    [Senate Hearing 116-252]
    [From the U.S. Government Publishing Office]

                                                            S. Hrg. 116-252

     MARIJUANA AND AMERICA'S HEALTH: QUESTIONS AND ISSUES FOR POLICY MAKERS

    =======================================================================

                                    HEARING

                                   BEFORE THE

                SENATE CAUCUS ON INTERNATIONAL NARCOTICS CONTROL
                              UNITED STATES SENATE

                         ONE HUNDRED SIXTEENTH CONGRESS

                                 FIRST SESSION

                                   __________

                                OCTOBER 23, 2019

                                   __________

      Printed for the use of the Senate Caucus on International Narcotics
                                    Control

    [GRAPHIC NOT AVAILABLE IN TIFF FORMAT]

                         Available via: www.govinfo.gov
                Senate Caucus on International Narcotics Control

                                   __________

                        U.S. GOVERNMENT PUBLISHING OFFICE
    41-181 PDF                  WASHINGTON : 2021

    --------------------------------------------------------------------------------------

                               JOHN CORNYN, Texas
                          DIANNE FEINSTEIN, California
                              JACKY ROSEN, Nevada

                                C O N T E N T S

                                  ----------

                                                                       Page
    Panel I Consisting of:
    Jerome Adams, MD, Surgeon General of the United States,
      Department of Health and Human Services, Washington, DC........     4
    Nora Volkow, Ph.D., Director, National Institute of Drug Abuse,
      North Bethesda, MD.............................................     5

    Panel II Consisting of:
    Robert Fitzgerald, Ph.D., Professor of Pathology, University of
      California-San Diego, San Diego, CA............................    17
    Staci Gruber, Ph.D., Professor of Psychiatry, Harvard Medical
      School, Boston, MD.............................................    19
    Sean Hennessy, Pharm.D, Ph.D., Professor of Epidemiology,
      University of Pennsylvania Perelman School of Medicine,
      Philadelphia, PA...............................................    21
    Madeline Meier, Ph.D., Assistant Professor of Psychology, Arizona
      State University, Tempe, AZ....................................    22

     MARIJUANA AND AMERICA'S HEALTH: QUESTIONS AND ISSUES FOR POLICY MAKERS
                      CAUCUS ON INTERNATIONAL NARCOTICS CONTROL
                                  ----------

                          WEDNESDAY, OCTOBER 23, 2019

                                           U.S. Senate,
                                                        Washington, DC.
        The hearing was convened, pursuant to notice, at 3:22 p.m.,
    in 215 Dirksen Senate Office Building. Senator John Cornyn,
    Chairman, presiding.
        Members Present: Senator Dianne Feinstein, Co-Chairman and
    Senator Jacky Rosen.
        The Chairman. Good afternoon. I would first like to begin
    this hearing by thanking our witnesses, and thanks to my Co-
    Chair, Senator Feinstein. We have been looking for a forum to
    have a hearing like this. As in so many areas, it seems like we
    are putting the cart ahead of the horse, and we would now
    really like to hear from the experts about what they can tell
    us about the public health consequences of marijuana use in the
    country.
        So far this year we have centered our efforts on prevention
    of addictive substances from entering the country and
    infiltrating our communities, but now we want to talk about
    something a little different.
        As you know, a 2018 Report by the Substance Abuse and
    Mental Health Services Administration found that an estimated
    43.5 million Americans used marijuana in the last year. The
    percentage of the population 12 years of age and older
    currently using marijuana has increased in recent years from
    under 7 percent in 2010 to more than 10 percent in 2018.
        And while marijuana is still a prohibited drug under
    federal law, more than 90 percent of the states allow for some
    medical use of marijuana in some capacity, and 10 states and
    the District of Columbia now allow for the recreational use of
    marijuana.
        Despite growing acceptance and accessibility of this drug
    and its derivatives, I believe we lack definitive evidence on
    the short- and long-term health implications of marijuana use.
    That is especially true for vulnerable populations like
    adolescents, pregnant women, and people suffering from mental
    health issues.
        Earlier this year, our Surgeon General, one of our
    witnesses here today, issued an Advisory that highlighted the
    risks of marijuana use for pregnant and nursing women and
    adolescents.
        I remain concerned about the lack of evidence regarding
    health risks of these groups, as well as the general
    population. And it may be helpful at some point for the
    witnesses to discuss what type of evidence that the medical
    community considers conclusive, or at least solid enough to
    make a policy determination on. Because there seems to be a lot
    of folk myths and other idiosyncratic ideas that really have
    not gone through the sort of peer review and published
    requirements that most scientific evidence has to go through in
    order to be accepted by policymakers.
        In 2017, the National Academy of Sciences, Engineering, and
    Medicine published one of the most comprehensive studies on the
    research of the health effects of recreational and therapeutic
    use of marijuana and cannabis-derived products.
        It included nearly a hundred conclusions. They found
    conclusive or substantial evidence that cannabis or
    cannabanoids, but not necessarily marijuana or marijuana-
    derived cannabanoids, are an effective treatment for chronic
    pain, chemotherapy-induced nausea and vomiting. However, they
    found insufficient or no evidence regarding potential
    therapeutic effects of cannabis or cannabanoids for a variety
    of health conditions considered.
        Additionally, they found substantial evidence that
    marijuana use had increased the risk of motor vehicle crashes,
    the development of schizophrenia, and other psychoses, and
    complications in pregnancy like lower birth weight.
        It is critical for people like Senator Feinstein and I and
    other policymakers to understand the public safety implications
    of increased marijuana use before we dive into the admittedly
    complex and difficult job of changing federal policy.
        In 2018, the Food and Drug Administration approved the
    first drug with an active ingredient derived from marijuana to
    treat rare, severe forms of epilepsy. It was only after
    rigorous studies and a thorough review by the FDA that
    physicians can have confidence in the safety, efficacy, and
    consistency of that drug. All this is to say that there are so
    many questions that still need to be answered.
        Surgeon General, Dr. Volkow, and the experts on our second
    panel will help shed light on what science tells us about the
    public health risks of marijuana and what we still need to
    learn.
        I look forward to hearing the testimony and discussing how
    we can work to prevent youth access to marijuana, and properly
    evaluate the safety and efficacy of any therapies that may
    utilize marijuana and cannabinoids.
        Let me now turn the floor over to my Co-Chairman, Senator
    Feinstein, for any opening remarks she would care to make.
        Co-Chairman Feinstein. Thanks very much, Mr. Chairman. As
    you know, I enjoy very much working with you, so this is a
    pleasure.
        The point of today's hearing is to better understand
    marijuana's impact on public health, and so I thank you very
    much for holding it.
        One thing I have learned is that marijuana is much more
    complex than I thought. It apparently contains hundreds of
    different compounds, all of which produce different effects. I
    am told that much of what we know about marijuana is anecdotal,
    which of course is problematic for us in terms of making
    policy. It is problematic for medical professionals in knowing
    how to treat it. And it is problematic for consumers when they
    use it.
        I am told this is due in part to the fact that marijuana's
    status as a Schedule One Drug makes it difficult to research.
    It is my belief that science should inform our policy, and that
    is why I, along with Senator Grassley and others, introduced
    the Cannabidiol and Marijuana Research Expansion Act which
    would remove barriers to research.
        The NIH recently increased the number of grants awarded to
    study marijuana, and I hope it will continue to do so. This
    will enable marijuana's potential therapeutic benefits really
    to be more understood as they are explored.
        It is important that we learn more about appropriate dosing
    and delivery mechanisms. It is important that we learn how
    marijuana components interact with other medications, how long-
    term use impacts the body. It is my understanding that the
    limited existing research has found varying degrees of evidence
    that components of marijuana may effectively treat conditions
    like intractable epilepsy, chemotherapy-induced nausea. I know
    that for a fact from family issues. And, vomiting. Muscle
    spasticity, chronic pain, and short-term sleep disturbances.
        The Food and Drug Administration has approved four
    marijuana-derived drugs to treat many of these illnesses.
    Despite the potential benefits, it is equally important to
    understand its adverse effects.
        For instance, studies show that marijuana can have a
    negative impact on the developing brain--this is one thing I
    hope to hear a little more about--including decreased cognitive
    abilities, loss of IQ, and increased risk of psychosis.
        I am going to end here, Mr. Chairman, in the interests of
    seeing--of listening to our panel, and I will put my remarks in
    the record. Thank you.
        The Chairman. Thank you, Senator.
        Our first witness is Vice Admiral Jerome Adams who serves
    as the 20th Surgeon General of the United States. During his
    tenure as Surgeon General, Dr. Adams has created several
    initiatives to tackle our Nation's most pressing health issues,
    including the opioid epidemic, oral health and the links
    between community health and both economic prosperity and
    national security.
        The Surgeon General issued an Advisory in August of this
    year on the potential health effects of marijuana use for
    adolescent brain development and use by pregnant mothers.
        Our second witness on the first panel is Dr. Nora Volkow,
    who has served as Director of the National Institute of Drug
    Abuse, or NIDA, since May 2003. That is quite a run. As a
    research psychiatrist and scientist, Dr. Volkow pioneered the
    use of brain imaging to investigate the toxic effects and
    addictive properties of abusable drugs.
        If I could ask each of you to limit your opening statement
    to about five minutes, and then we will make your complete
    statement part of the record, and then we can engage in some
    questions and answers, that would be great.
        So let me turn to you, Dr. Adams, to start, please.

    STATEMENT OF JEROME ADAMS, M.D., SURGEON GENERAL OF THE UNITED
                                 STATES

        Dr. Adams. Thank you very much, Chairman Cornyn, Co-
    Chairwoman Feinstein, and members of the Caucus. I appreciate
    the opportunity to share my recent marijuana advisory with you
    and to join national experts to discuss a complex issue that I
    feel demands our attention and our action.
        As you mentioned, in August 2019 I issued a Surgeon
    General's Advisory on Marijuana Use in the Developing Brain,
    emphasizing the importance of protecting our Nation from the
    health risks of marijuana use in adolescence and during
    pregnancy.
        I did this in response to alarming rates of marijuana use
    among pregnant women and young people, widespread and growing
    access to increasingly potent marijuana through legalization at
    the state level, and mounting evidence that marijuana use poses
    a risk to healthy brain development and to public health.
        As Surgeon General I have visited with communities and
    clinicians in places like California and Colorado, Georgia and
    Texas, Nevada and Oklahoma. And as a former state health
    commissioner myself, I have spoken with health department
    leaders across the country, my friends, many of them reluctant
    overseers of an enormous and poorly informed national public
    health experiment.
        Over and over I hear great and escalating concern about the
    rapid normalization of marijuana use, and the impact that a
    false perception of its safety is having on our communities,
    and specifically our young people and our moms-to-be.
        As you mentioned, sir, as of today 33 states and the
    District of Columbia have legalized marijuana in some way. I
    will say it again: We are conducting a massive public health
    experiment on our citizenry. And with greater legalization,
    young people are reporting a decline in perceived harmfulness
    of the drug. In 2018, only a third of adolescents said they
    thought weekly marijuana use was harmful.
        Marijuana is now the third most commonly used elicit
    substance in adolescents, behind alcohol and e-cigarettes. Last
    year, over 9 million 12- to 25-year-olds reported marijuana
    use, and each day 3,700 adolescents become new marijuana users.
        Unfortunately, the scary truth is that while the perceived
    harm of marijuana is decreasing, the potential for harm is
    actually increasing due to widespread access, increased
    potency, and multiple forms.
        Marijuana is now everywhere, especially in states that have
    legalized. And it can be smoked, drunk, eaten, and baked. As I
    like to say, this ain't your mama's marijuana. Not enough
    people know that today's marijuana is far more potent than in
    days passed. The amount of THC has increased three-fold in
    commonly cultivated plants over the last few decades, and
    dispensary products are often much stronger. Edible oils and
    waxes can deliver unpredictable concentrations of THC often of
    70 percent or more. This is important because the higher the
    THC concentration, the higher the risk to our young people.
        Across the country we have seen increased emergency
    department visits for psychosis and for nonfatal overdose. The
    earlier and more often a person uses marijuana, especially at
    these higher THC levels, the greater the peril.
        Nearly one in five people who begin marijuana usage during
    adolescence will become addicted. Yes, you can become addicted
    to marijuana.
        Science tells us frequent marijuana usage during
    adolescence can impair a child's attention, memory, and
    decisionmaking, and young people who regularly use marijuana
    are more likely to show a decline in IQ in school performance,
    are more likely to drop out, and are even more likely to
    attempt suicide.
        In pregnant women, marijuana is actually the most commonly
    used elicit substance. Between 2002 and 2017, marijuana use
    among pregnant women doubled. Marijuana usage during pregnancy
    can not only affect the baby's brain, but also can result in
    lower birth weight, a marker for early death and disability.
    And that is why that is so important.
        The Colorado PRAM study revealed a 50 percent increase in
    low birth weight in marijuana-using moms. THC is transmitted
    via breast milk, meaning the risk continues even after
    delivery.
        And finally, marijuana and tobacco smoke share some of the
    same harmful components, so no one should smoke either product
    around the baby.
        We already know a lot about the harms and potential harms
    of marijuana use on the developing brain, but I will be the
    first to admit we need to know more. We need to better
    understand the long-term health consequences of prenatal and
    youth exposure to marijuana, as well as strategies to decrease
    harms.
        But I want you to hear me say this: We know enough now to
    deliver sound guidance to protect the future of our Nation's
    youth. My Advisory includes resources to help parents,
    teachers, clinicians, and others safeguard our youth from harm,
    but it will take all of us using the best evidence and
    communicating it clearly to ensure a healthy future for our
    young people.
        This Advisory was carefully written based on the best
    currently available science, with input from NIDA, SAMPHSA,
    CDC, FDA, ACOG, AAP, and others. So please go to
    surgeongeneral.gov and share it.
        I will finish by saying my bottom line to you today is
    this: No amount of marijuana use during pregnancy or
    adolescence is known to be safe. Therefore, communities must
    consider and should not minimize the short- and long-term
    public health impacts of marijuana use.
        Thank you again for the opportunity to share this important
    information, and for your support in promoting healthy fetal
    and adolescent development to protect the youth of America. And
    I look forward to your questions.
        The Chairman. Thank you, Doctor. Dr. Volkow.

     STATEMENT OF NORA VOLKOW, Ph.D., DIRECTOR, NATIONAL INSTITUTE
                OF DRUG ABUSE, NORTH BETHESDA, MARYLAND

        Dr. Volkow. Good afternoon. Thanks very much for having me
    here, Chairman Cornyn and Co-Chairman Feinstein, and for
    holding this hearing on marijuana.
        It is an opportunity for us to bring to you what we are
    funding at the National Institute on Drug Abuse and what type
    of research we are funding to try to clarify the effects of
    marijuana in the young brain.
        As you mentioned, in 2018 there were 43.5 million people
    who reported use of marijuana in the past year, making it the
    most commonly used illicit drug in the United States, and its
    use is increasing.
        Marijuana exerts its effects by activating cannabinoid
    receptors which are part of our endogenous cannabinoid system
    that modulates multiple physiological processes in our brains
    and bodies. This system emerges early in gestation when it
    plays a critical role in helping to orchestrate brain
    development, which is why exposure to marijuana during early
    development can impact the function of the brain later in life.
        THC, the component of marijuana responsible for its
    intoxicating and addictive effects, freely crosses the
    placenta. Fetal exposure is associated with significant
    negative outcomes, including fetal growth restriction, lower
    birth weight, and preterm delivery.
        Research is ongoing to clarify the mechanisms through which
    it contributes to these effects, and to investigate the effects
    of marijuana to the fetal brain when used by itself or when
    combined with teratogenic drugs such as alcohol and nicotine.
        Adolescents, whose brains are also undergoing major
    developmental changes, are also particularly vulnerable to the
    negative effects of marijuana. Clinical studies of THC exposure
    during adolescence have shown greater sequence sensitivity to
    the rewarding effects of other drugs, which could be one reason
    why dosages of marijuana at a young age are more vulnerable to
    addiction later in life, not just to marijuana but to also to
    other drugs.
        Epidemiological studies have found repeatedly that kids who
    regularly consume marijuana have lower academic achievements
    and a higher risk of dropping out school. Brain imaging studies
    have shown that frequent marijuana use during adolescents is
    associated with structural and functional changes in areas of
    the brain necessary for attention, memory, emotions, and
    motivation, which might account for the adverse cognitive and
    behavioral effects associated with youth marijuana use.
        The association between marijuana use and mental illness is
    another area of major concern, particularly in light of the
    higher content of THC in today's marijuana. Serious mental
    illnesses and suicide are on the rise in our country. And while
    multiple factors are likely contributing to this rise, it is
    imperative to understand if exposure to high potency cannabis
    in adolescence is one of them.
        High potency marijuana can trigger acute psychotic
    episodes, which is one of the main causes for emergency
    department visits associated with cannabis use, which are also
    rising.
        While most of these episodes are short lasting, they can
    become chronic. Multiple studies, though not all, have
    associated adolescent marijuana use with an overall risk for
    the early onset of chronic psychosis such as schizophrenia.
        Adolescent marijuana use is also associated with increased
    risk of suicidal behavior. Many of the studies done to assess
    the effects of adolescent marijuana use have been criticized
    because of certain limitations. For example, some of them may
    have not controlled for other factors that affect adolescent
    brain development. Some may have had insufficient sample sizes.
    Most of them were conducted at the time when THC content in
    marijuana was much lower.
        To address this shortcoming, NIDA is leading two major
    studies. Study one is the Adolescent Brain Cognitive
    Development, or ABCD study, which is the largest long-term
    study of brain development in child health in the United
    States. The study has recruited over 11,000 children, aged 9 to
    10, who will be followed into early adulthood to investigate
    how the brain develops, and how its development is affected by
    substance use, including marijuana.
        The other one, which complements the ABCD study, is A
    Healthy Brain Child Development, or HBCD study, which is part
    of the NIH initiative and is currently in its pilot phase. This
    study would establish a large cohort of pregnant women and
    their infants to assess the child's brain cognitive and
    emotional development longitudinally over the course of the
    first 10 years of their lives. Findings will help researchers
    develop standards for normal brain development in childhood and
    to characterize the long-term impact of prenatal and postnatal
    drug exposures.
        Ensuring normal brain development is fundamental for
    achieving a person's full potential, which is why we owe it to
    the future generations to protect them from the potentially
    disruptive effects of cannabids to their brains and well being.
        Thank you very much, and I look forward to your questions.
        The Chairman. Thank you very much, both of you.
        I am struck, Dr. Adams, by your description as a poorly
    informed national health experiment with regard to marijuana.
    And of course part of what we are trying to do today is have a
    better informed discussion about this national health
    experiment.
        I see some parallels, perhaps--and I would be interested in
    your commentary on this--to what we learned about tobacco
    decades in the past. I even went back, with my staff's help,
    and found some advertisements by the tobacco industry where
    they would tout the health benefits of smoking. And not only
    were those not proven using the sort of peer-reviewed evidence,
    scholarship that we would expect, but there was not disclosure
    of the negative, the detriment to health--things like addiction
    to nicotine, lung cancer, cardiovascular disease, and the like.
        And I feel like there are some parallels, perhaps, here in
    the way we are wading into this debate. Do you think that is
    analogous, Dr. Adams, and Dr. Volkow? Or is it different?
        Dr. Adams. Well, sir, thank you for saying that. Because as
    the Surgeon General, I want every policy decision to have as
    much science infused into it as possible. And you are correct.
        We have seen this play before. We have seen it with a
    number of substances. Once upon a time, cocaine was thought to
    be an effective medicine and harmless. Once upon a time,
    opioids were thought to be good for whatever ails you, and to
    not have any harmful effects and no higher dosage limit.
        And not that I am in any way, shape, or form comparing
    marijuana to those substances, but from a policy point of view
    I think the lesson we should have learned was that we have to
    make sure the science is leading the policy, and that the tail
    is not wagging the dog. And many of the indications that people
    are using marijuana for are unproven. We are overstating the
    benefits and, in my opinion, we are downplaying the risks. And
    that is why I put out my Advisory, because one risk we cannot
    afford to ignore is the risk to our pregnant women and our
    young people, our Nation's future.
        The Chairman. Dr. Volkow.
        Dr. Volkow. Yes, I will completely agree, and I do want to
    state also the other aspect that we are learning with the use
    of marijuana at very high content, is we are finding out
    medical negative effects that we did not know existed. For
    example, a perfect example is the iferamesic syndrome where
    people that take high content THC chronically develop a
    syndrome where they cannot stop vomiting, with very, very
    intense abdominal pain.
        This was not described until 2006. And again, we have never
    seen it because we did not get exposed to this type of
    marijuana. So my concern relates to the fact that if we are not
    looking at something, particularly as we for example are
    discussing the use of marijuana in pregnancy, if we do not
    evaluate the outcome in these infants, we will not be able to
    understand what could be potentially very negative effects.
        And that is illustrated also with tobacco. In nicotine we
    did not know that smoking during pregnancy could have such
    negative effects until we studied it.
        Dr. Adams. And I am so glad you have someone on the second
    panel who is an expert on MVAs. There is this big misbelief out
    there that marijuana makes you a better driver, but the
    Colorado data shows us that MVAs went up, fatal MVAs went up in
    Colorado involving marijuana usage.
        And again going back to young people, I have got a teenager
    who is about to drive. The chips are already stacked against
    him. And we know that, just statistically speaking. The last
    thing we want is for these young people to think that marijuana
    use is safe or, Heaven forbid, that it actually will make them
    a better and more relaxed driver and lose even more of our
    teenagers on the roads now than what we already are.
        The Chairman. I know much of your testimony so far has
    focused on adolescents, pregnant women, and people with other
    conditions that would maybe make them more vulnerable, but are
    you suggesting, by inference, that marijuana consumption for a
    consenting adult who is otherwise healthy is harm-free?
        Dr. Adams. Well, as Surgeon General of the United States,
    the first thing I would say is absolutely not. There are plenty
    of substances out there which adults can partake of that are
    not only not harm-free, but which my office has a long history
    of trying to rein the horse back in on.
        You mentioned tobacco. Alcohol is one of the top killers of
    folks in our country. I think that again we need to learn from
    our mistakes and be careful about normalization of behavior.
        One of the other dangers about marijuana usage is that we
    do not know what we do not know. And so we do not want to
    conduct this experiment on our citizenry. And that is adults
    and young people. But we know enough about young people to take
    action now, and that is why I focused my efforts and my
    attention in that space at this point in time.
        But again, sir, I do not want anyone to mistake what I am
    saying as implying that these products are considered safe for
    general adult usage.
        The Chairman. Let me ask you about the research, because
    you have both referred to studies that have been done. Are
    there impediments, legal or otherwise, to the study of the
    health effects of marijuana in place?
        Dr. Adams. I will start off just by saying that Secretary
    Azar, the President, and I, have all stated publicly we need to
    make it easier to do research.
        The Chairman. What do we need to do to make that happen?
        Dr. Adams. Well, HHS is partnering with DEA. We are going
    around the country and talking to folks to find out barriers
    that exist to research. One of the things that has been
    announced within the past month was DEA making more strains of
    marijuana available so that folks can test more than just the--
    from the one facility in Mississippi, where you could typically
    get strains from.
        But Dr. Volkow is an expert in this area, and NIDA is
    intimately involved in the research process. So I would turn it
    over to her.
        Dr. Volkow. Part of the problem relies on the fact that
    marijuana is a Schedule One. And if you want to do research on
    a Schedule One, you have to get a DEA registration that can
    take, if you are lucky, one year to obtain, and that delays the
    process enormously.
        And every time that you make a change in your protocol,
    that also has to be submitted, and you have to wait for that to
    be approved. So it is a very lengthy, on the ability to get the
    research going. And then once you are going, right now the only
    source for marijuana that is available in our country is that
    that we provide through a contract to Missouri to a farm in
    Missouri.
        So if you as a researcher are interested in a particular
    strain of marijuana, you come to us at NIDA, it is probably
    unlikely that we have it and we will have to cultivate it. So
    the process also is very slow there.
        And finally, to the other component that makes it very
    difficult is that we are interested in understanding what
    people are taking out there. I mean, in the states they are
    legalizing marijuana and there are these dispensaries. And the
    varieties are very distinct.
        And so we do not know the difference between this or that.
    This product is being sold telling that it has this
    characteristic. We cannot fund research that relates to
    products that are actually being bought through these
    dispensaries because it is illegal.
        So we have been working for the past, I would say, several
    years with DEA to try to come up with an accommodation that
    would allow researchers to streamline the process so that they
    can work on an understanding both potentially negative but also
    potentially therapeutic effects of cannabids.
        The Chairman. Well I know Senator Feinstein mentioned some
    legislation that she is working on with Senator Grassley on the
    impediments to research, but that is perhaps something that we
    could work on together.
        Co-Chairman Feinstein. Great. I would love it. Thank you.
        Dr. Adams. Can I give a shout-out to Senator Feinstein? I
    am not allowed----
        The Chairman. Absolutely.
        Dr. Adams. I am not allowed to endorse or comment on
    pending legislation, but I was doing my homework. And you and
    Senator Grassley made a statement in the introduction of your
    legislation. You said medical treatment should be based on
    sound science, and for those who are sick that there are safe
    medications that have been proven effective.
        I could not agree with that more. And I think it is very
    important that folks such as yourself are acknowledging that
    and spreading that word.
        Co-Chairman Feinstein. Thank you.
        The Chairman. Senator Feinstein.
        Co-Chairman Feinstein. Thanks very much, Mr. Chairman.
        And thank you--[coughing], excuse me, I have a little
    throat problem.
        Dr. Adams. I am a doctor. I can help you with that.
    [Laughter.]
        Co-Chairman Feinstein. I may come to you.
        As I understand, investigations are ongoing. To date,
    nearly 1,500 lung injuries have been associated with the use of
    e-cigarettes and vaping products, with 33 confirmed deaths.
        THC has been present in most of the tested samples of these
    cases. Here is the question: Do we have enough research to
    understand the potential impacts of using e-cigarettes and
    vaping devices to consume marijuana products? What is the
    situation? And what happens to the lung when you use it?
        Dr. Adams. Thank you for that question. This is something I
    am terribly concerned about, and that HHS is really mounting an
    all-hands-on-deck response to.
        We have stood up our Emergency Operations Center at CDC. We
    are working with state and local health departments to get
    information in as quickly as possible. And you summarized it
    correctly, ma'am. A large number of these cases have been
    associated with vaping THC, particularly THC that has been
    obtained through the black market, if you will.
        Co-Chairman Feinstein. Explain what happens when you do
    this.
        Dr. Adams. Ma'am, well as an anestheologist I can tell you,
    God did not mean for much of anything besides oxygen to go into
    your lungs. And when you aerosolize oil and then suck it into
    your lungs and let it re-accumulate on the lining of your
    lungs, it can cause all sorts of bad things to happen.
        And I will also tell you, one of the big problems is we do
    not know what is in these pods. A lot of them are made on the
    black market, and the ones that are even made through, quote,
    ``legitimate sources'' we do not know all that is contained in
    them. And it is why last December I put out a Surgeon General's
    Advisory warning about the epidemic rise in vaping among young
    people, a 78 percent increase in vaping among students. And I
    pointed out at the time that a third of young people who were
    vaping had reported vaping marijuana.
        So I would say to you, before I turn it over to Dr. Volkow
    that, number one, the FDA and the CDC advised against vaping
    products containing THC.
        Number two, we advised not to modify or add any substances
    such as THC or other oils to products purchased in stores.
        And finally, no amount of marijuana usage during pregnancy
    or adolescence, no matter how it enters the body, is known to
    be safe. And no pregnant woman or young person should be
    vaping.
        Dr. Volkow?
        Co-Chairman Feinstein. Could I ask you a question? Have
    autopsies been done on the lungs of the 33 confirmed deaths? Do
    we know what happens to the lungs?
        Dr. Adams. Ma'am, what I would say is that--and again, I
    used to run a state department of health in Indiana. And one of
    the challenges is that these investigations start at a local
    level, and a lot of times the decisions about which samples are
    going to be collected, and which autopsies are going to be done
    are made before the state department of health is even alerted.
        And then the CDC finds out after that. So one of the big
    things that we are trying to help people understand is that we
    have to have a high index of suspicion. We have got to ask the
    right questions. And we should be doing an autopsy on all of
    these cases.
        Co-Chairman Feinstein. So autopsies have not been done?
        Dr. Adams. On some of them, but not all of them, ma'am.
        Co-Chairman Feinstein. On some of them?
        Dr. Adams. Yes.
        Co-Chairman Feinstein. Well what has been learned from the
    autopsies? What happens to the lungs?
        Dr. Adams. We know that there is damage to the cells of the
    lungs, to the tissues of the lungs. There is a lot of
    misinformation out there. Some of these cases had been reported
    to be associated with Vitamin E, and that was the case for some
    but it actually looks--it is an inflammatory injury. It is
    almost--I am trying to think of a good comparison--but again,
    it is as if a cell----
        Co-Chairman Feinstein. Enough to cause death?
        Dr. Adams. Oh, absolutely, ma'am. Lymphoid pneumonia has
    been found in some of these folks. But in other folks, it is as
    if the cells and the tissue were being eaten away. Again, you
    are putting toxic materials into the lungs that were never
    meant to be inhaled.
        Dr. Volkow.
        Dr. Volkow. Yeah, just basically in medical school they
    teach you that you should never, ever allow lipids to get into
    the lungs because they produce a very massive inflammatory
    reaction. So that's--and since you require the lungs to
    function properly for oxygen to be transferred, this is
    probably one of the reasons why it has had such negative
    effects.
        But I think it is also highlighting how we are approving
    these technologies in ways without recognizing what their
    negative effects are. And you are highlighting the acute
    effects. But, for example, we do not know what may be the
    effects on the function of the lung long term in those cases
    that you do not see this acute presentation.
        Co-Chairman Feinstein. Well let me ask this question. Are
    vaping devices well enough known? Do they bring on death----
        Dr. Volkow. Well, that----
        Co-Chairman Feinstein [continuing]. As it goes into the
    lungs? If you use--I do not know how to ask this question. If
    you use a vaping device, are you more apt to die?
        Dr. Volkow. Not necessarily. You are using a device that
    has quality control. And, for example, one of the things that
    we have done at NIDA is to develop a standard electronic
    cigarette that can be used to determine whether, for people
    that cannot stop smoking, that use of these vaping devices can
    help them actually be able to protect them from the negative
    effects of combustible tobacco.
        So provided that you have standards of quality control,
    both the device as well as the cartridges that you are using
    and the content of nicotine and the products, this device could
    be given as a therapeutic option for those that cannot stop
    smoking.
        Dr. Adams. And can I answer that question in another way,
    ma'am?
        Co-Chairman Feinstein. Yes.
        Dr. Adams. Even the people who are advocates for e-
    cigarettes and vaping devices describe them as ``harm
    reduction.'' Less harm does not mean harmless. No young person,
    no pregnant woman, no person who is not currently smoking,
    should even entertain using these devices. Because, again, you
    are taking substances that are in an unknown pod, and you are
    vaporizing them and taking them back into the lungs. And
    whether that is marijuana, or anything else out there, again we
    do not know what we do not know. But we know that those
    substances were never intended to go into your lungs, and they
    can be toxic.
        Co-Chairman Feinstein. Yes. I have particular concern about
    marijuana use by very young children. And the fact that--
    reports have shown that it results in a decline in IQ, in poor
    school performance, and higher rates of school absences.
        How prevalent is this?
        Dr. Adams. Let me take that at the 30,000-foot level, and
    then kick it to Dr. Volkow. It is important for us to
    understand, and a lot of folks say, well, I have smoked a
    joint, or I smoked marijuana back in the '80s, back in the
    '70s. The potency is much, much higher. A higher THC content
    equals more danger.
        Number two, not everyone is going to have the same effect.
    Every person is different. And so some people--as we know, some
    people smoke for five years and get lung cancer, and some
    people smoke for 50 years and do not get lung cancer.
        But if you are talking about a child, you want to give that
    child--I have three young kids--the best chance at life.
        Co-Chairman Feinstein. Yes.
        Dr. Adams. And we know that on a population level that the
    cumulative effects of having an entire population, 9 million
    young people using marijuana products is going to be a net
    negative for our country.
        But do you want to get into specifics, Dr. Volkow?
        Dr. Volkow. Yeah, I will just point out, I mean it is not
    surprising in a way because this endogenous cannabinoid system,
    one of the things that it does, it modulates the activation of
    neuronal networks. So when you are hyper-stimulated, it brings
    it down. When you are hyper-inhibited, it brings it up to
    create that certain window of optimal function. So if you are
    taking marijuana, in a way you are filtering many of those
    stimuli. And your development is dependent on those stimuli to
    actually create the final architecture.
        Co-Chairman Feinstein. How does marijuana impact school
    performance? What does it do to the brain?
        Dr. Volkow. The simplest one, it interferes with memory and
    learning. Someone that is stoned cannot remember. And that is
    not just adolescents, that is any adult.
        Co-Chairman Feinstein. I did not know that.
        Dr. Volkow. And as a result of that, if you are a student
    and your job is to learn, and marijuana stays in the body for a
    long time, you are going to have a long-lasting effect in your
    capacity to memorize and you will fail school.
        And that is without addressing the possibility that----
        Co-Chairman Feinstein. Is the memory loss permanent?
        Dr. Volkow. That is a question that there is controversy.
    There is some evidence that there is long-lasting impairment in
    memory and attention by some studies, and others show that
    after several months it recovers.
        And we don't--that is one of the reasons why we are doing
    the ABCD study, to actually, unequivocally determine if long-
    term use of marijuana will produce a long-lasting or
    irreversible change in memory, attention, and other process of
    cognition.
        Co-Chairman Feinstein. Wow. Is it because marijuana today
    is stronger, the THC factor?
        Dr. Volkow. That is not going to help at all. The content
    is much, much higher. And the higher the content--it is
    actually three-fold higher overall, and----
        Co-Chairman Feinstein. Wait, wait, wait. I am not trying
    to--three times higher than when?
        Dr. Volkow. Than 2002.
        Co-Chairman Feinstein. Really?
        Dr. Volkow. Yes.
        Dr. Adams. Ma'am, there was a study that looked at
    marijuana from 1995 till 2014, and they saw that marijuana in
    1995 the average strains were about 4.5 percent THC. The
    average strains in 2014 were about 12 percent. So that is where
    we get the three times number. But it is important to remember
    now that dispensaries have marijuana that is testing at about
    20, 25 percent. So that would be five times stronger than 1995.
        And then when you put it into oils and waxes, you can get
    70, 80, 90 percent THC. So I hate comparisons, but something
    that I say to folks that tends to resonate is, that is like the
    difference between having a light beer in 1995 and drinking a
    pint of vodka today. It is literally that much of a difference
    in concentration.
        Co-Chairman Feinstein. I do not think people know that.
        Dr. Adams. I do not think they do either, ma'am.
        Co-Chairman Feinstein. How do we get that out?
        Dr. Adams. Well, again, the Surgeon General Advisory. We
    need you all to help share it at surgeongeneral.gov. Please let
    people know this ain't your mother's marijuana.
        Dr. Volkow. And the other problem that is confounded is
    that when you go and buy a product, you do not actually know
    what the content of 9 THC is. And this particularly becomes
    problematic when you get an edible. You get the chocolate and
    you do not know the content, and so you do not know how much to
    take of it.
        And one of the reasons why people end up in emergency room
    admission with a psychotic episode is because the content is so
    high.
        Co-Chairman Feinstein. Well, now how big a problem is this?
        Dr. Volkow. In terms of emergency department----
        Co-Chairman Feinstein. No, the high content of
    hallucinogenic quality in marijuana today versus 10--excuse me,
    10, 15 years ago?
        Dr. Volkow. It is very problematic. And studies have
    consistently shown, for example, that investigate the negative
    effects of marijuana that the higher the content of 9-THC the
    greater the likelihood that you will have a psychotic episode.
    The greater the likelihood, actually, the risks associated with
    schizophrenia----
        Co-Chairman Feinstein. Which changes the nature of beliefs
    about marijuana. Because most people that I know believe it is
    relatively harmless. And what you are saying is, it is not
    today; that it is much stronger, and that it is much more
    volatile.
        Dr. Adams. Exactly. And Dr. Volkow is an expert and speaks
    on the effects on the individual, and she has, again, spoken of
    her wonderful brain imaging studies. I tend to look at the
    population level. And the metrics we look at are motor vehicle
    accidents going up. Emergency department admissions going up.
        Co-Chairman Feinstein. For marijuana use? You can prove
    that?
        Dr. Adams. Yes, ma'am. The emergency department admissions
    have gone up for accidental ingestions and for people showing
    up with psychosis. We are seeing all sorts of untoward effects
    from marijuana usage, again particularly in young people. But
    real concerning population health trends related to marijuana
    usage.
        Co-Chairman Feinstein. Could you provide us with some
    information? We may want to put out a paper as a result of
    this, and that might be one of the things that we would
    discuss.
        The Chairman. Well I know that has been one of the
    functions of this Caucus in the past, is to issue reports or
    papers on different topics, and certainly that is something we
    ought to consider doing.
        Co-Chairman Feinstein. Because I have young people in my
    family and, you know, you think it is all nothing. Hopefully
    they do not use it, but they sure can talk about it. So I think
    if I am understanding what you are saying, the potential danger
    of marijuana has gone up rather dramatically in the last 10, 15
    years?
        Dr. Adams. The potential danger has gone up, while the
    perceived harm of the product has gone down. And what I was
    quoting in my opening statement was NISDA data that looks at--
    that surveys young people from SAMPHSA. SAMPHSA data that
    surveys young people and asks them their perception of the
    dangers of marijuana. And their perceptions of danger are going
    down, particularly in states that have legalized, because they
    see it all around them. While the actual risk, both from a
    scientific point of view and on a population health level, is
    going up.
        Co-Chairman Feinstein. What has California done?
        Dr. Adams. Well, you have got someone from the California
    Cannabis Research Commission who is going to be on the second
    panel.
        Co-Chairman Feinstein. Oh, good.
        Dr. Adams. And I have been out there. I visited U.C. Davis.
    I have visited U.C.S.D. I have been to the L.A. County Health
    Department. I will tell you that all of the health officials I
    have spoken to are terribly concerned about the spike in
    pregnant women who are using.
        We have seen a doubling in pregnant women who report using
    marijuana, and they are concerned about the number of young
    people. It is causing disciplinary problems in schools, and we
    do not know what the long-term health effects are going to be.
    So in your State, ma'am, we are very concerned.
        Co-Chairman Feinstein. So just quickly, how is it more
    concentrated, more volatile, than it used to be?
        Dr. Volkow. The plant itself. I mean, like in biology you
    can determine the content of the active ingredients by breeding
    up varieties that have higher content. And that is how they
    have come up with plants that have higher and higher content,
    manipulating it.
        And now, with the use of resins, you can extract the active
    ingredient and put it in a cartridge----
        Co-Chairman Feinstein. Oh, dear.
        Dr. Volkow [continuing]. And that gives you even higher
    content. So this is just basically genetic, what the
    agricultural business has been doing to try to improve on the
    quality of the plants.
        Co-Chairman Feinstein. So we should not regard it as
    ``harmless''?
        Dr. Volkow. Oh, it is not harmless at all. And when you
    were asking about your own state, there were actually showing
    me that one of the emergency departments in one of the main
    hospitals in San Diego where they basically will have an eight-
    fold increase in emergency admissions from the cannabis over a
    period of eight years. Eight-fold. It is gigantic.
        Co-Chairman Feinstein. This is not just vaping----
        Dr. Volkow. This is not just vaping----
        Co-Chairman Feinstein. Oh, I thought you said----
        Dr. Volkow [continuing]. And smoking, and edibles, and
    every single way of administering cannabis.
        Co-Chairman Feinstein. So if a mother uses this strong
    stuff while she is pregnant, will that impact----
        Dr. Volkow. She can become psychotic herself. High-content
    THC, what people do not realize is high-content marijuana with
    very high THC can trigger an acute psychotic episode. And that
    leads you to the emergency department. It is a horrible
    experience.
        Co-Chairman Feinstein. What if she is pregnant? What does
    it do to the unborn child?
        Dr. Volkow. Well, you have there, on top of the negative
    effects to the mother, the fact that the marijuana will go into
    the fetus and affect the brain of the fetus. The fetus cannot
    complain, right?
        Co-Chairman Feinstein. Right.
        Dr. Volkow. But it is going to very likely be interfering.
    Imagine that there is this very precise process by which your
    brain determines when this neuron migrates here, when this
    neuron divides, when this neuron interconnects with another,
    and that is modulated by your own endogenous cannabinoid
    system.
        When you artificially stimulate that system, you are
    basically disrupting all of that perfect orchestration. That is
    why we have so much concern about the use of marijuana among
    pregnant women, children, and adolescents.
        Co-Chairman Feinstein. Can a baby be born addicted to
    marijuana?
        Dr. Volkow. I do not know of any description of a baby
    having been born addicted to marijuana. But what we do know is
    that babies can be born sedated because of the use of
    marijuana, particularly during the last trimester.
        But the condition of a baby that is born addicted, that has
    not been something that has been documented.
        Dr. Adams. And ma'am, something that again I was just in
    your state two weeks ago talking about were the infant
    mortality rates. We know one of the predictors of infant
    mortality is low birth weight. Well I was shocked when I saw
    the Colorado PRAMS data that showed that women who smoke
    marijuana have a 50 percent increased chance of having a baby
    born at low birth weight.
        And so that is another thing that people do not think about
    when they are prescribing marijuana to women who are pregnant
    or could be becoming pregnant.
        Co-Chairman Feinstein. Thank you.
        The Chairman. Well, unfortunately we are going to have to
    stop there with the first panel, because we obviously have a
    lot of questions and we want to continue the conversation, but
    we want to get to the second panel, too.
        So thank you, Dr. Adams, Dr. Volkow, for your contribution.
    And, believe me, we want to continue the conversation. Because
    as you can see, Senator Feinstein and I, and I am sure our
    other colleagues who could not be here today, have a lot of
    questions. And I think the American people deserve the facts,
    which is what we are trying to get to here.
        So thank you very much, and we will invite the second panel
    to come forward and get situated, and we will get started in
    just a second.
        Dr. Adams. And, Senator, we are happy to submit any
    information you need about the harms of marijuana usage that we
    have collected. Please share my Advisory, surgeongeneral.gov.
    We need to get the word out to folks that this is not some
    harmless product out there.
        The Chairman. We will do that, sir. Thank you.
        Dr. Volkow. And thanks for doing the hearing.
        The Chairman. Thank you.
        (Pause.)
        Well thank you very much. Our second panel includes experts
    who have conducted research on various aspects of public health
    and marijuana use.
        First, Dr. Robert Fitzgerald, who currently serves as a
    Professor in the Department of Pathology at the University of
    California-San Diego, where he is also the Director of the
    Toxicology Laboratory, Director of the Toxicology Laboratory,
    and Associate Director of the Clinical Chemistry Laboratory. He
    is Board Certified in Toxicology and Clinical Chemistry by the
    American Board of Clinical Chemistry, and his research, Senator
    Feinstein, focuses on marijuana-impaired driving. I know you
    had questions about that.
        Dr. Staci Gruber is Director of the Cognitive and Clinical
    Neural Imaging Core and the Marijuana Investigations for the
    Neuroscientific Discovery Program, otherwise called the MIND
    Program, both housed at the Harvard-affiliated Psychiatric
    Hospital in Belmont, Massachusetts' McLean Hospital. She is
    also an Associate Professor of Psychiatry at Harvard Medical
    School. Her research focuses on cognitive development and the
    effects of marijuana's major constituent compounds.
        Dr. Sean Hennessy is Professor of Epidemiology in Bio
    Statistics at the University of Pennsylvania's Perelman School
    of Medicine. Dr. Hennessy conducts research in the field of
    pharmacoepidemiology. That is a mouthful. Which is the study of
    the health effects of drugs and other medical products in
    populations. Dr. Hennessy is the past Scientific Chair and past
    President of the International Society for Pharmacoepidemiology
    and has served as the FDA's Drug Safety and Risk Management
    Advisory--served on that committee, the Drug Safety and Risk
    Management Advisory Committee for the FDA. Dr. Hennessy
    contributed to the National Academies of Science's 2017 Study
    on Marijuana's Health Effects.
        And finally, Dr. Madeline Meier is the Assistant Professor
    of Psychology at Arizona State University and Post-Doctoral
    Fellow, with support from the Duke University Trans
    Disciplinary Prevention Research Center. Her research interests
    involve adolescent marijuana use, as well as the health effects
    of marijuana concentrates.
        So obviously there is a lot of interest in what you have to
    say. If I could first recognize Dr. Fitzgerald and ask each of
    you maybe to speak for about five minutes, and then maybe be
    open to some questions. Your written remarks will be made part
    of the record, without further ado.
        So, Dr. Fitzgerald.

    STATEMENT OF ROBERT FITZGERALD, Ph.D., PROFESSOR OF PATHOLOGY,
             UNIVERSITY OF CALIFORNIA-SAN DIEGO, CALIFORNIA

        Dr. Fitzgerald. Thank you, Senator, Senator Feinstein. It
    is a pleasure to be here today to discuss issues related to
    marijuana and driving.
        As a way of brief introduction, my first job out of
    graduate school was as a forensic toxicologist from the State
    of Virginia where I helped work with the medical examiner to
    determine the cause and manner of death in medical examiner's
    cases.
        At the ME's office, I saw the devastating effects of
    driving under the influence on a routine basis. I also had the
    opportunity to work with both state and local law officers,
    along with prosecution and defense, to present scientific data
    in courts of law.
        Currently I am a clinical toxicologist at UC-San Diego
    where my research focuses on developing analytical methods to
    measure concentrations of THC and metabolites following recent
    marijuana exposure.
        I am part of a large team of investigators at the
    University of California-San Diego's Center for Medical
    Cannabis Research focused on understanding both beneficial and
    detrimental effects of cannabis on human health. We recently
    completed enrolling subjects in one of the largest studies to
    date looking at the effect of smoked marijuana on driving
    performance, and are in the initial stages of analyzing this
    data.
        The relationship between marijuana use and driving
    impairment is complex because of the unique pharmacokinetics--
    that is the time course in the body, and pharmacodynamics--that
    is its physiological effects--of THC.
        With ethanol there is a clear relationship between amount
    consumed, blood concentrations, and effect on driving. With
    marijuana, these types of relationships are much more complex.
        The relationship between blood THC concentrations and crash
    risk has not been established. But there is a clear
    understanding that THC impairs driving performance. The
    question that remains is how to best identify drivers who are
    impaired by marijuana. There are no perfect solutions, and
    legislative directives must balance keeping our roadways safe
    with due process.
        The problems with determining the relationship between
    concentrations of THC and impairment is that levels of THC vary
    widely depending on the route of administration, the time of
    sampling after dosing, and the characteristics of the
    individual consuming.
        Generally, smoked marijuana causes effects that start
    shortly after inhalation and last for about three hours. While
    subjects who eat marijuana start feeling effects about an hour
    later, and can have effects up to eight hours later.
        Unlike alcohol, which is cleared within 24 hours of
    drinking, THC and several metabolites accumulate in the body
    with repeated dosing. So frequent users have baseline
    concentrations of THC that exceed the per se limits in many
    states.
        After smoking, THC concentrations in blood change rapidly.
    And our studies have documented the poor relationship between
    concentrations of THC and measures of impairment. Studies like
    this led the National Safety Council to put out a Position
    Statement in 2017 that reads: ``It is further concluded that,
    due to rapid changes in blood THC concentrations over time,
    there is no minimum safe threshold blood concentration below
    which a driver can be considered to have been unaffected while
    driving following recent marijuana use. Consequently, there is
    no scientific basis for the adoption of THC per se laws for
    driving.''
        This statement was also supported by the International
    Association of Chiefs of Police. Despite these position
    statements, 18 states currently have some form of per se
    statutes.
        How do we keep our roads safe? In California, prosecution
    of driving under the influence of drugs is currently based on
    officer observations combined with toxicology testing. This
    practice will likely continue for the foreseeable future.
        Since there is no reasonable expectation that THC or a
    metabolite of THC will be useful for per se impairment, an
    alternative approach would be to develop methods that identify
    recent use. The biological specimens that could be used to
    determine if a driver has recently used marijuana are blood,
    breath, and oral fluid.
        The primary advantage of breath and oral fluid over blood
    is that they can be collected at the roadside at the time of a
    traffic stop, as opposed to blood which typically takes about
    90 minutes to collect.
        This is an important consideration because, unlike ethanol,
    concentrations of THC fall by more than 90 percent in that
    short time frame. There is a variety of ongoing efforts to
    identify recent-use markers.
        In respect to my time limit, I would like to close my
    initial statement by mentioning two items that I think this
    Caucus needs to be aware of so they can help shape appropriate
    regulations.
        Due to federal restrictions, investigators cannot study the
    cannabis products our population is exposed to. As Dr. Adams
    indicated, we have unleashed a massive experiment that is sort
    of uncontrolled in our population, and our most powerful
    resources, our research community, has limited ability to study
    that.
        This is a critically important public health issue that
    needs to be changed. Currently there is no standardized data
    collection for driving under the influence of drugs. Without
    good data, it is difficult to develop good policy.
        I hope my testimony was helpful and look forward to
    answering questions. Thank you.
        The Chairman. Thank you very much. Dr. Gruber.

      STATEMENT OF STACI GRUBER, Ph.D., PROFESSOR OF PSYCHIATRY,
             HARVARD MEDICAL SCHOOL, BOSTON, MASSACHUSETTS

        Dr. Gruber. Thank you, Senator Cornyn and Senator
    Feinstein, and members of the Caucus who may tune in later to
    see this----
        Co-Chairman Feinstein. Could you speak directly into the
    microphone?
        Dr. Gruber. Certainly. Is that better?
        Co-Chairman Feinstein. Yes.
        Dr. Gruber. I should be better at this.
        So as you have heard, and as we know, the Nation is in the
    midst of a green rush, and marijuana or cannabis headlines
    flood news outlets daily. Yet it is often difficult for people
    to read through study findings and make sense of what we know
    and what we do not.
        Despite the fact that 33 states have fully legalized
    medical marijuana, and another 15 have limited medical
    marijuana laws, leaving only 2 states without access, nearly
    all of what we know about the impact of marijuana comes from
    studies of recreational marijuana users.
        These studies typically focus on those with chronic, heavy
    marijuana use. Data across studies is somewhat inconsistent,
    but generally reflect differences between those who use
    marijuana and those who do not spanning a number of areas that
    we have heard allusions to already, including cognitive
    performance. Domains most commonly affected include memory and
    executive functioning. For example, the ability to inhibit
    inappropriate responses, or to use feedback to change one's
    behavior. These are reportedly impacted by marijuana use.
        Earlier onset of marijuana use, as well as higher frequency
    and magnitude of use, are also associated with greater
    difficulty on these tasks. And studies of brain structure and
    function have also reported deficits or differences between
    marijuana users and non-users, specifically as among early
    onset or adolescent users of marijuana.
        This is not surprising. As you heard from Dr. Volkow, we
    know that during adolescence the brain is neuro-developmentally
    vulnerable. That is, it is under construction. It is sensitive
    not just to marijuana but to other substances--alcohol,
    illness, injury.
        Another concern that we have heard a lot about today is the
    rising potency of marijuana products. Particularly problematic
    for youth, our most vulnerable consumer group, THC, the primary
    intoxicating compound of the plant has increased 300 percent,
    or more than three-fold, in flower products since 1995. And
    these novel concentrate products that we have also heard
    illusions to, Dabs, Shatter, Wax, you have heard these terms,
    THC levels of these products go at least up to and sometimes
    north of 90 percent.
        Cannabidiol, or CBD, may mitigate some of the negative
    effects that we see from THC, but it is virtually undetectable
    in recreational products today. Thus far there have been no
    studies that have directly assessed the impact of potency or
    novel versus conventional products in either recreational
    consumers or medical patients.
        It is also important to remember that not all marijuana use
    is the same. And our recreational marijuana consumers are not
    the same as our medical marijuana patients.
        For example, their goal of use is wholly different. Our
    recreational marijuana consumers--I have spent nearly 30 years
    with these folks--their goal is to change their current state
    of being, or to get high. Our medical marijuana patients are
    not interested in getting high. They use to alleviate symptoms.
    They say things like I want to sleep through the night. I would
    like to be able to take a drive with my son. I want to go for a
    walk with my kids.
        As a result, their product choices are often different.
    Recreational consumers often choose products very high in THC.
    Our medical patients choose products that may be high in THC
    but often contain other compounds, things like cannabidiol or
    other non-intoxicating compounds.
        Cannabis and cannabinoids have demonstrated therapeutic
    potential for a number of indications. We heard reference to
    the 2017 National Academy's report noting conclusive or
    substantial evidence that cannabis or cannabinoids were
    effective for, quote, ``the big three, chronic pain, nausea and
    vomiting as a function of chemotherapy, and muscle spasticity
    as a function of MS.
        We also know that epadadialexis or purified CBD extract was
    approved for pediatric onset intractable seizure disorders. But
    despite the fact that medical cannabis has been legal since
    1996, data regarding the impact of medical marijuana treatment
    is severely limited. Preliminary evidence from the very first
    longitudinal studies of medical marijuana patients demonstrate
    improvements in some areas of cognitive performance, including
    areas noted to be impaired in those with recreational use.
        We also see improvements in clinical state, better sleep,
    decreased pain, and notable reductions in the use of
    conventional medications including opioids, so important in the
    midst of this crisis.
        When it comes to marijuana, one size does not fit all. We
    have a single term, marijuana, and we often hear it used to
    refer to anything like the whole plant or individual compounds
    from the plant, intoxicating or not, which mean very different
    things.
        Current regulations around marijuana limit the type and
    scope of research projects we can do. And, contrary to popular
    belief, we cannot currently study the impact of products that
    patients and consumers are actually using via clinical trial
    models, significantly reducing external or ecologic validity.
        Further, as Dr. Volkow testified, the Schedule One status
    of marijuana leads to a number of obstacles in conducting
    research. Policy at this point has clearly outpaced science.
    And as the Nation has warmed toward both the use of medical and
    recreational marijuana, the need for empirically sound data is
    critical in order to maximize benefit and reduce harm.
        Regardless of how you feel about marijuana, science and not
    emotion or rhetoric must be our guide. We have a responsibility
    to provide the best and most accurate data to our medical
    marijuana patients, our recreational consumers, our health care
    providers, and the general public so they can make the best,
    most informed decisions about marijuana use.
        At this point, I would thank you for your ongoing efforts
    and being willing to help move things forward. Thank you.
        The Chairman. Thank you, Dr. Gruber. Dr. Hennessy.

       STATEMENT OF SEAN HENNESSY, PHARM.D., Ph.D., PROFESSOR OF
      EPIDEMIOLOGY, UNIVERSITY OF PENNSYLVANIA PERELMAN SCHOOL OF
                  MEDICINE, PHILADELPHIA, PENNSYLVANIA

        Dr. Hennessy: Good afternoon, Senators. My name is Sean
    Hennessy and I am a Pharmacist Epidemiologist at the University
    of Pennsylvania. I was a member of the 16-person committee that
    wrote this 468-page report entitled ``The Health Effects of
    Cannabis and Cannabinoids'' that the National Academics of
    Science, Engineering, and Medicine released in January 2017.
        The report is a comprehensive review and synthesis of the
    then-existing literature about the potential health effects,
    both therapeutic and harmful, of cannabis and cannabis-derived
    products.
        The report lists nearly 100 different conclusions about
    these effects. It also discusses four barriers to conducting
    research on cannabis and makes four recommendations on how to
    address research gaps.
        I would like to summarize this report as 6-4-4. Six health
    effects with high-level evidence. Four challenges to conducting
    research. And four recommendations to moving forward. So among
    the highest levels of evidence about the health effects of
    cannabis we made the following conclusions.
        One, cannabis use prior to driving appears to increase the
    risk of motor vehicle crashes, as we have heard about today.
        Two, in states where cannabis is legal, there is an
    increased risk of unintentional cannabis overdose in children.
        Three, pregnant women who smoke cannabis increase the risk
    that their baby will be born with lower birth weight.
        Four, initiating cannabis use at a younger age is a risk
    factor for developing problematic cannabis use later in life.
        Five, long-term cannabis smoking increases the risk of
    chronic breathing problems. And six, some people with chronic
    pain or muscle spasm from multiple sclerosis can obtain relief
    of their symptoms using cannabis-based products.
        Most of the studies for these uses examined orally
    administered cannabis extracts, rather than smoked cannabis.
    The report also identified the following four challenges to
    conducting research on the health effects of cannabis.
        One, there are specific regulatory barriers, including the
    classification of cannabis as a Schedule One substance that
    impede research.
        Two, it is difficult for researchers to gain access to the
    quantity, quality, and type of cannabis product that they need
    to conduct research.
        Three, it is difficult to obtain funding to support
    cannabis research. And four, improvement and standardization in
    research methods are needed.
        Finally, the report makes the following four
    recommendations:
        One, public health agencies and other groups should fund a
    national cannabis research agenda.
        Two, agencies of the U.S. Department of Health and Human
    Services should convene a workshop to develop a set of federal
    standards and benchmarks to guide high-quality research on
    cannabis.
        Three, federal, state, and local health authorities should
    fund improvements to the public health surveillance system.
        And four, the CDC, NIH, FDA, and others should convene a
    committee to characterize regulatory barriers and propose
    strategies to develop the resources and infrastructure that are
    needed to conduct cannabis research.
        I thank you for your attention and the opportunity to
    discuss these important issues, and look forward to answering
    your questions.
        The Chairman. Thank you, Dr. Hennessy. Dr. Meier.

      STATEMENT OF MADELINE MEIER, Ph.D., ASSISTANT PROFESSOR OF
          PSYCHOLOGY, ARIZONA STATE UNIVERSITY, TEMPE, ARIZONA

        Dr. Meier. Good afternoon, Mr. Chairman and Senator
    Feinstein.
        Co-Chairman Feinstein. Could you speak directly into the
    mike? It is hard to hear.
        Dr. Meier. Thank you for inviting me to contribute to my
    knowledge about cannabis effects on cognitive functioning.
        The most comprehensive study of cannabis use in cognitive
    functioning was published by our group in 2012. Today I am
    going to describe that 2012 study and explain the findings, why
    they are important, and what additional research is needed.
        We have studied the association between persistent cannabis
    use over time and change in IQ from childhood to adulthood. And
    we asked whether cannabis effects on IQ were concentrated among
    adolescent onset cannabis users. That is, cannabis users who
    began using before age 18.
        Data came from the Dunedin Study, which is a study of 1,000
    children born in 1972 and '73 in Dunedin, New Zealand, and
    followed from birth to age 38, with 96 percent of the sample
    taking part in the study at age 38.
        IQ was tested at age 13, before anybody in the cohort had
    started using cannabis, and again at age 38 after some members
    of the cohort had been using cannabis for years. We found that
    persistent cannabis use from ages 18 to 38 was associated with
    decline in IQ. And this decline in IQ was concentrated among
    adolescent onset persistent cannabis users. These are cannabis
    users who began using cannabis before age 18 and continued
    using for many years thereafter.
        Specifically, individuals who began using cannabis in
    adolescence before age 18, and used it for years showed an
    average 8 point IQ decline from childhood to adulthood.
    However, individuals who used cannabis short-term in
    adolescence showed only weak evidence of IQ decline.
        Further, individuals who began using cannabis in adulthood
    sometime after age 18 did not show decline in IQ even when they
    used persistently.
        Quitting or reducing cannabis use did not fully restore
    intellectual functioning. Decline in IQ could not be explained
    by alcohol or other drug use, or by reduced years of education
    among cannabis users.
        Decline in IQ could also not be explained by low childhood
    socioeconomic status or poor childhood self-regulation. Friends
    and relatives reported noticing more attention and memory
    problems in everyday life among the persistent cannabis users.
    These findings are important for a number of reasons.
        First, an especially important feature of this study is
    that we had IQ test data from both before and after study
    members started using cannabis. This allowed us to rule out the
    possibility that IQ deficits in cannabis users predate the
    onset of cannabis use.
        We showed that regardless of their IQ test performance in
    childhood, adolescent onset persistent cannabis users performed
    worse than nonusers, and worse than adult onset cannabis users
    on IQ tests in adulthood.
        Second, the eight-point IQ decline we observed among
    cannabis users who began using cannabis in adolescence and
    continued using for many years is non-trivial. For example, an
    average person has an IQ of 100, placing them in the 50th
    percentile for intelligence, compared to same-age peers. If
    this average person loses 8 IQ points, they drop from the 50th
    to the 29th percentile for intelligence.
        Third, IQ is a predictor of a person's access to a college
    education, their lifelong total income, their access to a good
    job, and their performance on the job. Individuals who lose 8
    IQ points may be disadvantaged relative to their same-age peers
    in many important aspects of life. In fact, the adolescent
    onset persistent cannabis users from our 2012 study ended up in
    occupations that were less prestigious, less skilled, and less
    well paid than their parents' occupations.
        Finally, only about 2 percent of the sample became those
    adolescent onset persistent cannabis users. Thus, any effect of
    cannabis on IQ is confined to a relatively small segment of the
    population. Nonetheless, findings are concerning given that
    fewer adolescents today believe that regular cannabis use
    presents a serious health risk.
        Additional research is needed to answer the following
    questions:
        One, what are the mechanisms underlying cannabis-related IQ
    decline?
        Two, what are the parameters of cannabis use that determine
    the magnitude and persistence of cognitive deficits? These are
    things like frequency, duration, quantity of use, and potency.
        Three, does cognitive functioning recover with abstinence?
        Four, are there individual differences in susceptibility to
    cannabis-related cognitive deficits?
        To answer these questions, we need large-scale longitudinal
    studies to follow use from before to well after cannabis
    initiation, and to combine cognitive testing with brain imaging
    to better understand the mechanisms that might underlie
    cannabis-related decline in IQ.
        The Adolescent Brain and Cognitive Development Study was
    launched in part to meet this need. Thank you.
        The Chairman. Thank you, Dr. Meier.
        Welcome, Senator Rosen. Thank you for joining us. Let me
    start with a five-minute round of questioning.
        Dr. Gruber, just a point of clarification. We heard from
    the previous panel that THC concentrations in recreational
    marijuana have at least tripled. But I see in your paper you
    say that you believe it has quadrupled from 1995 to 2017. Is
    that correct?
        Dr. Gruber. I think the prior panel referenced the paper
    that was published----
        I think the prior panel referenced the paper that was----
        Co-Chairman Feinstein. Louder, please? I'm sorry.
        Dr. Gruber. Sure. Is that better? I think the prior panel
    referenced the publication from 2014----
        The Chairman. Oh, okay.
        Dr. Gruber. At that time, the difference from '95 to 2014
    was about three times.
        The Chairman. Three times?
        Dr. Gruber. Right now, the average potency across the
    Nation from government-seized products is about 17 percent.
    That is contrasted to about just under 4 percent in 1995.
        The Chairman. Okay, so that is significant. You think the
    best information is it has quadrupled in concentration?
        Dr. Gruber. I would say in terms of national averages for
    THC, that is right.
        The Chairman. But----
        Dr. Gruber. Those were recreational products.
        The Chairman. But you also point out--and this is really
    the point I wanted to get to--is that there are concentrates,
    other products that have been created. You mentioned things
    like Dabs, the colloquial name for concentrated oil, created by
    extracting THC from flower-based marijuana products, Shatter
    Wax, Butter, and others, that all have a significantly higher
    concentration potency compared to conventional marijuana
    products as high as 80 percent more concentrated. Is that
    correct?
        Dr. Gruber. Or higher, absolutely right. This is the
    recreational market that is very focused on increased THC
    because if the goal of use is to become intoxicated, or to
    change your current state of being, you are looking for
    products that will deliver that bigger bang for the buck, if
    you will. So these products are very, very popular and becoming
    more popular across the Nation in the recreational market.
        The Chairman. Well it strikes me as significant. If you
    smoke it, it is about four times more powerful than it was in
    1995. But you can take it in a concentrated form that could be
    80 percent of traditional marijuana product.
        Dr. Gruber. Exactly. THC is significantly higher, as we
    heard from our first panel, significantly higher these days
    than in prior years.
        The Chairman. Well I can imagine just from a scientific
    standpoint trying to figure out what the dosing is, and what
    the effect of a dose is very difficult given the range of ways
    that people can get access to the active ingredient.
        Dr. Gruber. Mode of use is very important in terms of onset
    of effects and duration of effects. Absolutely true. Especially
    important for our medical cannabis patients.
        The Chairman. Dr. Fitzgerald, you have done a lot of work,
    you said, in terms of its impact on impaired drivers. Would it
    be fair to say that the concentration of THC and whether it is
    consumed from recreational use of smoking marijuana compared to
    these concentrates? Does it have a--is there a correlation
    between the concentration of the product that you consume and
    the level of impairment for drivers?
        Dr. Fitzgerald. So I think that is one of the issues that
    Dr. Adams brought up, as well, is that we have not even been
    able to study the Dabs and the concentrates. It is not possible
    to do those studies, currently.
        The Chairman. But those are not standardized products? I
    mean, like you would be able--you cannot compare widgets to
    widgets, I guess.
        Dr. Fitzgerald. Correct.
        The Chairman. Because they are all sort of concocted by
    whoever makes them, according to their own recipe, and the
    like.
        Dr. Fitzgerald. Several issues there. One, we do not know
    what is actually in those. They are labeled. California
    actually does have a reasonably good laboratory system for
    analyzing plant materials, as well as Dabs and things for
    pesticides and concentrations of THC. But that is only in the
    legal market. And the legal market, unfortunately, is a small
    share of the total market of recreational marijuana.
        The Chairman. As we know, there has been an unfortunate
    increase in suicides in the country, a lot of concerns about
    our Veterans in particular, but not just Veterans. It is just
    young people and others who end up taking their life.
        I wonder, do you find any correlation between self-
    medication of people with underlying mental health disorders
    that get exacerbated by the use of marijuana or some of these
    concentrated products?
        I do not know who would be the most appropriate person to
    ask. If you have an opinion, please jump in.
        Dr. Gruber. I have an opinion, since I work in a
    psychiatric hospital and have been seeing the patients for
    about 30 years.
        The Chairman. It sounds to me like you are qualified.
        Dr. Gruber. Maybe, I don't know. It's under debate. I can
    tell you that there are many, many patient populations that
    derive real benefit from using cannabis or cannabinoid-based
    products. And the potential risk for individuals with
    undiagnosed conditions or disorders--you know, where we hear
    about these individuals who are using and not necessarily
    disclosing, or they are self-medicating. One of the important
    things to be mindful of is that it is not necessarily the
    cannabis. But we have to be mindful of what is driving the
    cannabis use.
        Individuals who have different types of conditions, as I
    mentioned, often get benefit from use. But it is very, very
    important to watch these people over time and to look at the
    impact versus, you know, sort of a cross-sectional assessment,
    in a longitudinal fashion.
        No doubt some individuals with differing conditions have
    their conditions exacerbated by cannabis use. That is why it is
    so important to be able to identify the most likely compounds
    from the plant which may make things worse versus those which
    may make things better.
        In fact there is evidence to suggest some compounds from
    the plant may actually really positively impact some of these
    conditions that we see. And this is why so many people are
    turning toward them. But without real empirically sound data to
    guide these types of studies, we have limited ability to give
    them information.
        The Chairman. Well my understanding, my layman's
    understanding, is that there is some evidence that epilepsy can
    be treated using THC-related products.
        Dr. Gruber. Cannabidiol.
        The Chairman. Okay. Is there any--what other benefits have
    you been able to identify based at least on anecdotal
    information, in the absence of these longitudinal studies? What
    other benefits do you suspect may be derived from use of
    marijuana?
        Dr. Gruber. So different compounds from the plant may very
    well have individualized benefits. We know about cannabidiol. I
    think this was mentioned in your bill. Cannabidiol has been
    shown to potentially be efficacious not just for epilepsy,
    which is now approved by the FDA, Epidialial Schedule Five, but
    for other conditions. There have been some interesting studies,
    including preclinical work, in areas like anxiety. A number of
    different conditions may be positively impacted by cannabidiol.
    Other compounds may yield, again, therapeutic potential, but we
    do not have much in the way of long-term studies. And
    unfortunately, it is very difficult to study these compounds
    using clinical trial models, sort of the gold standard for
    deriving empirically sound data, given our current
    restrictions.
        We have an ongoing--we just started a long-term clinical
    trial, open label to double-blind, of a whole plant full
    spectrum product for patients with anxiety. This data will be
    very, very important since so many people turn to things like
    CBD and they say it is good for this, it is good for this, and
    it would be great to have empirically sound data to lean on to
    actually guide patients and care givers.
        The Chairman. I even have a friend who said they put CBD
    product in their pet food----
        Dr. Gruber. Sure.
        The Chairman [continuing]. So their pet--it relieves their
    pet of anxiety. So I guess it cures everything.
        Dr. Gruber. I do not know about everything, but there is
    some data from studies outside of this country, small studies,
    in terms of cannabidiols' impact on anxiety, some pre-clinical
    work, and finally some work here. So it certainly begs the
    question of how much more we need, which in my opinion is a lot
    more. But we are starting.
        The Chairman. Thank you. Doctor--Doctor Feinstein? Senator
    Feinstein. (Laughter.]
        Co-Chairman Feinstein. Thank you. Thirty-three states and
    the District of Columbia have legalized marijuana in some form.
    And each state has its own laws and regulations.
        Should we be concerned that the lack of uniformity across
    states in terms of testing, labeling, packaging, the strength
    of products that may be sold, how they may be advertised, and
    how they may be accessed, can lead to consumer confusion? And
    this could produce unintended acute public health effects,
    including increased emergency room visits.
        In Colorado, for example, there was a three-fold increase
    in marijuana-related emergency room visits between 2012 and
    2016. So here is the question:
        Would uniform regulations across states be helpful to
    ensure consumer safety and reduce public health impacts such as
    emergency room visits associated with marijuana use? Who would
    like to go--why don't we just go right down the line. If you
    have a comment, make it. If you do not, you do not.
        Dr. Fitzgerald. Yes, certainly I think California is a
    model there for the fact that all the state-approved marijuana
    has actually been through a very sophisticated testing scheme
    to show its purity, show that it does not have pesticides, show
    it does not have fungus, and those things. There is some
    question about the reliability of different laboratories, and
    it would be nice to have a reference laboratory that everyone
    else sort of standardizes against. That would be useful to have
    uniform labeling. And certainly the CDC can be helpful in that
    regard.
        Co-Chairman Feinstein. Thank you.
        Dr. Gruber. I think it is incredibly important to have
    uniformity.
        Co-Chairman Feinstein. I am having trouble hearing you.
        Dr. Gruber. I think it is incredibly important to have
    uniformity, and even more important to have full disclosure of
    ``what's in your weed''? People have no idea very often what
    they are getting. So I think it is incredibly important, since
    states make their own, sort of their own rules and regulations
    about what is allowed.
        In my State of Massachusetts--and I spend a lot of time in
    California as well--these things are clearly defined in terms
    of testing for aflatoxins, heavy metals, pesticides,
    contaminants, yeast, mold----
        Co-Chairman Feinstein. So a standard across the United
    States would be helpful?
        Dr. Gruber. I think having a reference standard would be
    incredibly important in making sure every state does thorough
    testing is critical.
        Co-Chairman Feinstein. Thank you.
        Dr. Hennessy. I agree. I do not have anything to add.
        Co-Chairman Feinstein. Thank you.
        Dr. Meier. I agree, as well, and do not have anything
    additional to add.
        Co-Chairman Feinstein. Okay. What is the most common form
    of marijuana concentrate being used by adolescents? And how
    much THC does it contain? Adolescent use is my big concern.
        Dr. Meier. My group just published I believe the first
    epidemiological study of that. And we found that you can talk
    about concentrates as a general class, but there are two really
    different types of concentrates--one that is extracted using a
    solvent like butane--and those tend to have generally higher
    concentrations than the other class of concentrates where the
    THC is extracted using ice, or just rubbing it. And that has
    still much higher THC content than, for example, marijuana
    which is the buds of the cannabis plant. And that adolescents
    are using all of that. But primarily they are using the
    solvent-extracted----
        Co-Chairman Feinstein. They are using the what?
        Dr. Meier. The solvent-extracted concentrates.
        Co-Chairman Feinstein. What is that?
        Dr. Meier. Which go by names, various names. Dabs is the
    generic name to refer to just taking a very small kind of waxy
    piece of the concentrate. But then there's Butane Hash Oil, or
    they call it BHO, and it is called that because you extract the
    concentrate with butane solvent.
        It is also called ``Honey Oil,'' ``Crumble,'' lots of
    different names for it. And while those products look
    different, one can look like a waxy sticky substance, one can
    look like butter, they all contain similarly high levels of
    THC.
        Co-Chairman Feinstein. Ah-hah. So are they heavily used by
    adolescents?
        Dr. Meier. We know from the State of Arizona one in four
    adolescents have said they have tried concentrates.
        Co-Chairman Feinstein. So what would you suggest we do, if
    anything?
        Dr. Meier. I think we need--my primary concern is educating
    parents and people like you to recognize what a concentrate is.
    It does not look like marijuana. It looks very different, and
    recognizing that that contains very high levels of THC which
    could pose risks to health.
        Co-Chairman Feinstein. Well would you have a standard for
    this? Does that makes sense? Or should government get involved
    in this? I think, you know, when you talk about adolescents,
    you do not want them to die and you do not want them to become
    addicted.
        Dr. Meier. Correct. We do not want them to become addicted.
    But we still need to do research on whether adolescents who use
    concentrates are more likely to become addicted than if they
    use the lower THC marijuana.
        So I think we need more research, because some evidence
    suggests that it is possible that these concentrates will not
    have ill effects if adolescents are titrating their use, which
    means using less when the THC content is high.
        Co-Chairman Feinstein. Thank you. Thanks, Mr. Chairman.
        The Chairman. Senator Rosen.
        Senator Rosen. Well thank you. I want to thank Chairman
    Cornyn, Ranking Member Feinstein, for holding this important
    hearing. I want to thank all of you for your years of school
    and research and dedication to this extremely important topic.
        I want to talk a little bit about medical marijuana.
    Although marijuana is legal in Nevada for both medicine and
    recreational purposes, the research that you are doing is so
    important for my state's hospitals, providers, schools,
    parents, law enforcement agencies, anybody that is concerned
    with the public health impact. And there are approximately in
    Nevada about 17,000 medical marijuana patients.
        So this research that you do really impacts their lives,
    their ability to seek treatment for their medical conditions.
    And so with that in mind, I really appreciate the bipartisan
    approach which has led to this hearing, and I hope the
    conversation will continue to be research and science based. It
    is so important that we have these longitudinal studies,
    epidemiological studies, so on and so forth. It makes a real
    difference as to how our communities can educate and legislate,
    if we need to, to do the right thing.
        But I want to talk about the potential benefits of medical
    cannabis in treating our Nation's Veterans. We have over
    220,000 Veterans in Nevada. And, let me tell you, I do not have
    to tell you how much they do struggle. They struggle with
    chronic pain. They struggle with depression, anxiety, post
    traumatic stress symptoms, and in too many cases they are
    becoming addicted to medications prescribed to them--opioids,
    other things like that.
        Our Veterans have given so much to their country, they just
    want to come back. They want to claim their lives and continue
    to serve their communities in whatever way is good for them and
    their families.
        And so VA providers are currently prohibited from
    recommending or prescribing cannabis use. The VA will not
    reimburse Veterans for medical marijuana prescriptions from any
    source.
        Former VA Secretary David Shulkin, he stated last week he
    believes the VA should be involved in research and anything
    that could potentially help Veterans and their wellbeing.
        So to Dr. Hennessy, and then anyone else after, you were a
    member of a committee that conducted rigorous overview of
    available research on the potential health benefits of
    cannabis, or therapeutic benefits. It also identifies barriers
    to research and you made recommendations.
        So I would really appreciate your thoughts of how we might
    use cannabis to help our Veterans through anxiety and
    depression in those ways, and find alternatives to treat the
    issues that they are suffering from when they come home.
        Dr. Hennessy. So thank you for your question, Senator. So
    of the uses that you mentioned, there is randomized trial data
    supporting the use of cannabis products for chronic pain. And
    the cannabis products that were studied most often for chronic
    pain was an oral solution of one-to-one THC to CBD. It was not
    either smoked or vaped cannabis.
        The other indications that you mentioned, anxiety,
    depression, PTSD, there are not good data from randomized
    trials that support the efficacy of either whole cannabis or
    cannabis-derived products for those indications.
        Lack of evidence does not mean that the products are not--
    that none of the constituents of cannabis are not effective. In
    some cases it merely means that the studies have not been
    conducted, or not enough of them have been conducted to
    identify a beneficial effect, if there is one.
        Senator Rosen. But you would support us funding, or lifting
    the ban on some of the research to find out if we can use these
    products effectively, Dr. Gruber?
        Dr. Gruber. Yes. And thank you so much for focusing on this
    issue. We have a program through the MIND program called
    Serving Those Who Have Served. And it is dedicated to our
    Veterans. Because so many are already using cannabis of
    cannabanoids for treatment, many are interested in using it.
    But we have no real data.
        Senator Rosen. Right.
        Dr. Gruber. So, you know, we come at this as a quasi
    clinical trial because we cannot administer products that are
    in the marketplace, given our current federal regulations and
    restrictions. So we do the best that we can.
        But we followed these folks over time, longitudinally. And
    we need more data like that to be able to really understand the
    impact. As referred to by Dr. Hennessy, we do not have a ton of
    data. But certainly lifting anything that would allow greater
    research efforts to be made I would be in favor of.
        Senator Rosen. Well thank you. I want to--you spoke about
    chronic pain, and I was fortunate enough to be able to start
    the Comprehensive Care Caucus, which is focusing on palliative
    care, people living with a terminal illness or chronic disease,
    and they need palliative care, although they may not be getting
    curative care.
        And so can you speak to the effects of how we could use
    cannabis in the palliative care spectrum for those, as I said,
    living with chronic disease, or living longer with terminal
    illness, to relieve some of the symptoms that they may be
    having as a result of their disease?
        Dr. Hennessy. Sure. So one of the symptoms that patients in
    palliative care experience is chronic pain. And as I mentioned,
    there are clinical trials showing that oral solutions of
    cannabis extract are effective for chronic pain.
        In terms of other indications for use in the palliative
    care setting, I think more research is needed to be able to
    recommend them as effective therapies. We do not want to
    recommend therapies and offer false hope to people for
    therapies that end up not being effective. That, in addition,
    has side effects on their own.
        Senator Rosen. Right. Thank you.
        Dr. Gruber. I think it is also important, just to dovetail
    on what Dr. Hennessy is saying, to be able to assess the actual
    products that patients are using, as opposed to just sort of
    guessing. And the one-to-one ratios of oral solutions, things
    like Sativex, are not necessarily in the marketplace for our
    palliative care patients.
        Our ongoing longitudinal study at the MIND program actually
    follows patients with chronic pain as a subgroup, and they
    demonstrated improvements over time using lots of different
    products. But this research is really in its infancy, and this
    is, as far as I know, the only longitudinal study like this in
    the country.
        Senator Rosen. Right.
        Dr. Gruber. We need a lot more.
        Senator Rosen. Well I applaud all of your work, and I do
    think that particularly in the medical space trying to find the
    ways that we can use marijuana, whether for chronic pain,
    anxiety, terminal disease, PTSD, depression, if we can find
    ways that make people--help them go better through their lives,
    then it is definitely worth researching. And I appreciate your
    hard work. Thank you.
        The Chairman. Thank you, Senator Rosen.
        Dr. Gruber, I think I understand what you were telling me
    earlier. Let me just confirm I got this right. There is a part
    of marijuana that will make you high. That is THC, right? The
    active ingredient?
        Dr. Gruber. That is the primary psychoactive compound in
    the plant, yes.
        The Chairman. Okay, that is a more eloquent way of saying
    it than I did. And then there are other products from the
    marijuana plant, or that can be derived from that, like CBD
    that you think has some medicinal or beneficial effects? But
    that has little or no THC in it. Correct?
        Dr. Gruber. Correct. Just to clarify, really quick and
    dirty, cannabis sativa-L, the plant, is comprised of hundreds
    of compounds. The primary psychoactive compound is THC. That
    gets you high. The primary non-intoxicating constituent is
    cannabidiol, shown to have tremendous--at least thought to have
    tremendous therapeutic benefit.
        There are many, many other cannabinoids--canabachromine,
    canabajeral, tetrahydro canabaren, as well as terpinoids, the
    essential oils that give cannabis its characteristic scent and
    flavor profile that have also been touted to have potential
    beneficial effects. Flavanoids. The plant is incredibly
    complex. It is not just THC and CBD, although I know that is
    where we start our discussions, but it is important to remember
    that alongside THC we have CBD and other players.
        The Chairman. Would it be possible for Congress to de-
    schedule or to treat CBD and other non-THC products differently
    than it would THC or psychoactive components of the plant?
        Dr. Gruber. As I understand it, currently under the
    Controlled Substance Act anything that comes from the plant
    cannabis sativa with greater than .03 percent THC by weight
    falls under Schedule One. Anything that comes from industrial--
    so-called ``industrial hemp'' legalized in the 2018 Farm Bill,
    or Hemp Bill, CBD from that source is legal. So that is de-
    scheduled.
        The Chairman. So Congress has already carved out an
    exception, basically, for hemp?
        Dr. Gruber. For industrial hemp-derived CBD, ostensibly the
    DEA will allow those types of research studies to move forward.
        The Chairman. And what differentiates those two, is one has
    a negligible, if any, THC component.
        Dr. Gruber. That's right.
        The Chairman. And the other product that is a psychoactive
    one has the THC at a much more concentrated level.
        Dr. Gruber. Much more concentrated levels. Both plants have
    THC. Industrial hemp maxes out by definition as .03 percent THC
    by weight. Cannabis sativa-L, when we think of marijuana, we
    think of that plant that can be bred to have very, very high
    levels of THC, as well as levels of other cannabanoids. There
    are differences in the two cultivars.
        The Chairman. Well that is helpful. Thank you, very much.
        Senator Rosen, do you have anything else you would like to
    ask?
        [No response.]
        The Chairman. Well, let me express my gratitude to each of
    you and our previous panel of witnesses. This is a conversation
    we should have started a long time ago, but I am glad at least
    we are starting it now.
        And as you can tell, there is a lot we have to learn,
    Members of Congress, the policymakers, but I think the American
    people. I think the risks, the health risks of marijuana use
    have been undersold, and as we heard from the previous panel,
    but yet there are beneficial uses that do not involve the
    psychoactive component we have heard that could be enormously
    helpful.
        So this has been very informative and so I thank you for
    it. Thank you for your participation. We are going to close the
    hearing now, but we will leave the record open for another week
    in case any member of the Caucus has written questions they
    would like to ask to follow on.
        But taking Senator Feinstein up on her suggestion, it may
    be that the Caucus would decide to publish a white paper on
    what we have learned here, perhaps for the benefit of others,
    including policymakers like ourselves, and that is something we
    are going to look into as well.
        So we look forward to continuing the conversation with you,
    and thank you very much for being here.
        (Whereupon, at 5:01 p.m., Wednesday, October 23, 2019, the
    hearing in the above-entitled matter was adjourned.)
        [Questions and answers and submissions for the record
    follow.]
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