NASEM Report Recommends Removing Barriers to Cannabis Research

Photo of marijuana coming out of a prescription bottle ©Shutterstock/Atomazul

Last month, the National Academies of Science, Engineering, and Medicine (NASEM) released a major new report on the health effects of cannabis and its constituent compounds, based on a comprehensive assessment of research conducted since 1999. The National Academy of Medicine, formerly the Institute of Medicine (IOM), is a nonprofit organization of medical and health professionals whose reports provide independent research reviews and recommendations on pressing issues in the field. The Health Effects of Cannabis and Cannabinoids is its first report on the subject since 1999, when (as the IOM) the organization reached the conclusion that "accumulated data indicate a potential therapeutic value for cannabinoid drugs, particularly for symptoms such as pain relief, control of nausea and vomiting, and appetite stimulation."

The new report is based on reviews of research on both the cannabis plant itself and its constituents, but its conclusions are substantially similar to the 1999 report: While cannabis use, particularly smoked cannabis, poses some long-term health and safety risks, there is evidence that cannabis or cannabinoids can treat certain medical conditions, which include nausea and vomiting from chemotherapy, spasticity from multiple sclerosis, and pain.

However, most research to date on the therapeutic potential of cannabinoids has studied individual cannabinoid chemicals, especially delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). And while the full report is highly detailed and provides appropriate caveats for the limitations of the research, I have concerns that the report summary and press coverage may give the impression that the findings apply equally to the cannabis plant ("medical marijuana") and to the cannabinoid formulations that have undergone rigorous clinical trials. In addressing potential therapeutic benefits of the cannabis plant and its constituents, it is important to explicitly identify the cannabinoid tested to avoid mistakes such as ascribing the potential antiepileptic effects of CBD to "marijuana," which usually contains less than 1 percent of this cannabinoid.

Even the existing evidence on cannabis and cannabinoids for pain, rated as "strong" in the NASEM report, is based on research with limitations. For studies using the cannabis plant (5 total), the sample sizes were small, studies were short (with duration under 2 weeks, which is too short to assess effectiveness for chronic pain), and they were subject to problems with blinding. The strongest evidence comes from studies with isolated cannabinoid compounds (e.g., THC), not the whole plant. Nevertheless, there are modest but consistent positive findings reported for treating certain types of pain with cannabis, suggesting a promising area for further therapeutic development. 

"Medical marijuana" that has any appreciable THC content may have notable adverse side effects, including impairment of judgment and motor function and the risk of addiction. Unfortunately, there are currently no consistent quality controls, no assurances that patients are informed about side effects, and unclear recommendations about dosing and route of administration. It is important for people to understand the range of effects produced by cannabis as they weigh the risks and benefits for treating their health conditions with products from state dispensaries.

Regarding long-term psychosocial and mental health risks of marijuana use, the report largely supports the conclusion that use during adolescence is associated with various adverse outcomes and that it is associated with increased risk of psychosis and psychotic disorder and can worsen symptoms of these disorders. The report also found that cannabis use is associated with an increased risk for developing substance dependence other than cannabis use disorder. However, it did not find evidence that cannabis use raises risk of depression, anxiety, or post-traumatic stress disorder (PTSD), and it found only moderate support for links between cannabis use and poor academic achievement and educational outcomes. The NIDA does not concur with the latter conclusion: While it is true that the available data cannot establish causality of these adverse outcomes, the statistical association is consistent, substantial, and dose-related, especially for early and heavy use.

Regarding physical health effects of marijuana use, the report found a lack of clear evidence for any link to heart attack or stroke and lack of an association with cancers of the lung, head, and neck. Our sister Institute, the National Cancer Institute, does not concur with the strength of that conclusion, since disentangling the effects of tobacco from cannabis can be challenging and some data do suggest that a link to these cancers may exist. The report did find a link to low birth weight in babies born to mothers who used cannabis while pregnant but insufficient evidence at this point to draw strong conclusions on other childhood outcomes of prenatal exposure.

The NIDA strongly agrees with the report’s finding that there are impediments to performing quality research on cannabis and cannabinoids and that there is a need to address these impediments so that researchers can draw more confident conclusions. The report makes four major recommendations:

  • Address research gaps across the areas of basic and clinical research, policy, and public health and safety.
  • Identify strategies to improve the quality of research on cannabis, including better research standards and benchmarks.
  • Strengthen federal and state-based public health surveillance efforts to better track the effects of new policies.
  • Address regulatory barriers to cannabis research.

Although a single report could not hope to address all the complexities of cannabis, cannabinoids, and their health effects, NASEM is to be commended for tackling a massive and often contradictory literature and for making a strong case for the need for further research. We will have more confident conclusions about this drug's benefits and its harms only when it is easier for qualified researchers across the country to do high-quality research.

Dr. Nora Volkow, Director

Here I highlight important work being done at NIDA and other news related to the science of drug use and addiction.

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We are in the middle of an "opioid epidemic".
You say "there is evidence that cannabis or cannabinoids can treat certain medical conditions, which include nausea and vomiting from chemotherapy, spasticity from multiple sclerosis, and pain."

You don't say "YAY, THIS COULD HELP"?
Well, maybe, possibly, could be, may impair judgement, the plant itself, blah blah blah.
We are in the middle of an "opioid epidemic". We are where we are because of YOUR BEST THINKING.

Your "ho hum" reaction to the possibility of a NON-DEADLY, natural substance, which you just said is an effective alternative to treating pain, is indicative of the kind of thinking that continues to FUEL this "epidemic".

"Here we have a big fat HOSE filled with water"
"We've been staring at that hose since 1999, instead of USING IT, let's stare at it for ANOTHER TWO DECADES"

 Medical benefits

Legalizing recreational marijuana is a huge mistake in my thinking. When used recreationally, it is not regulated. It impairs judgement, mobility, and motivation. It is known to cause permanent brain damage if used during the adolescent years on into adulthood (adolescence ending when the brain is no longer developing...age 25 or 26, thereabouts). I keep hearing marijuana has medical value as a natural "drug" to treat a variety of issues, such as reducing the side effects of cancer treatment. WHY ARE WE NOT TREATING MARIJUANA AS ANY OTHER CONTROLLED SUBSTANCE???? SHOULD IT NOT BE SOLD IN PHARMACIES AND REGULATED LIKE ANY OTHER POWERFUL DRUG?


I always knew the cognitive impairment and memory impairment as well as motor coordination issues. I think other drugs such as meclizine assist with nausea and does not cause addiction as does marijuana or the above symptoms. I am not a supporter of medical marijuana or for legalizing recreational marijuana either as is a habit forming narcotic which does has serious side effects and dependencies.


I would like to volunteer for a study. The side effects pale in comparison to cancer, and the opioid epidemic. I actually happen to like the side effects.

Sign me up


I've never smoked marijuana, but I worked in the treatment industry for 20 years and saw how it affected lives. Medical marijuana? I had several clients tell me that one or both of their parents used marijuana for "medicinal" purposes. When I asked what they thought of that, they always told me it was just an excuse to get high. I thought one very successful businessman and father said it best when expressing the affects of his marijuana smoking over the past 25 years when he said: "A day doesn't go by when I look in the mirror and wonder "what could have been". I feel the same way. I have a son, now schizophrenic, who started using marijuana when he was 14. Not a day goes by that I don't look at him and wonder.."what could have been". What you are doing is NOT helpful! We have an Opiod epidemic and a Marijuana epidemic!!

 Drugs and drugs

Are the people suffering from multiple sclerosis aware of the range of effects produced by tizanidine, baclofen, or diazepam?
Causality and association remeber me Sir Austin Bradford Hill's words "Finally, in passing from association to causation I believe in 'real life' we shall have to consider what flows from that decision. On scientific grounds we should do no such thing. The evidence is there to be judged on its merits and the judgment (in that sense) should be utterly independent of what hangs upon it - or who hangs because of it. But in another and more practical sense we may surely ask what is involved in our decision".

 Thousands Stop Using Opioids, thanks to Cannabis

So NIDA will sit on the fence with all of the evidence at hand?
Then they are part of the farce that has been inflicted upon this great nation since 1937.

Pharmaceutical companies get rich by the billions as good people die every 20 minutes from their poisonous, FDA-approved HEROIN- and NIDA wants to sit back and wait some more?

The studies have been done for decades, NIDA. Stop following along with the FDA and DEA while they allow our veterans, parents, and children to be poisoned by their deadly pills. People have been benefiting from using cannabis ("marijuana") for thousands of years.
Honest education and regulation are bringing down teen use across the nation. Why do you think use is dropping?
Parents are teaching their kids the truth about cannabis.
It is not anything like heroin. It should not be Schedule 1. It never took a life.

Stop this never-ending, ill-fated, misleading FAKE DRUG WAR that is killing, addicting, and incarcerating our neighbors.
Tell the children the Truth. Then, maybe we will finally break the cycle of addiction.

 Marijuana use doubles last decade, so does heroin

Reasonable estimates suggest that regular marijuana use doubled during the last decade. Plus opioid addiction also rose correspondingly, even more so. Coincidence or not?

Let's realize that today's pot lobby is using ALL possible avenues to promote its agenda of widespread marijuana liberalization and acceptance. They claim that psychoactive marijuana (not just CBD) can cure all sorts of ailments, like it’s the world's new, all natural miracle drug. They are now even claiming marijuana can stem the opioid epidemic! Which seems equivalent to claiming beer consumption prevents alcoholism. Nutty!

In fact, the exact opposite may be true. That is, increased marijuana acceptance may be inadvertently expanding the lure for the opioids. That’s because many in their perpetual quest to get ‘high’, might begin to experiment with other drugs. The medical field needs to be very wary.

It’s very possible the pot lobby itself is inadvertently causing this horrible heroin epidemic.

 CaliforniaBill is entitled to his ideas just like FLAT EARTHERS

Bill thinks the "pot lobby" is "claiming marijuana can stem the opioid epidemic!".
BOTH Johns Hopkins University AND The Rand Corp have documented that states that have legal cannabis suffer 20% FEWER opioid deaths than states that don't.
These institutions have NO incentive to lie, and their credibility is beyond reproach!
He, erroneously, thinks it's a "nutty" claim by the pot lobby.

YES, cannabis use has gone up.
And as there are twice as many Americans under 21 than there are over 65, (US Census) adult use should be expected to continue to go up.
He neglects to point out though, that legality of cannabis has actually resulted in LOWER teen use of the plant (NIH).

Trying to connect the increase in cannabis use to the increase in opioid use is just a baseless idea swimming around in his head.

It has been well documented that reckless prescribing and false claims from drug companies have caused the opioid epidemic.
The continuous blundering of our nation's drug policies have only added to the problem.

Then, the MONEY. Yes, it is true that our nations #1 cash crop is OBVIOUSLY profitable!
Colorado ALONE took over $1.6 BILLION in cannabis sales off the black market last year and earned the state around $150,000,000.00 in cannabis tax.

Some people may think that the sales from our biggest cash crop should stay underground, or be diverted to Mexican criminals, but im not one of those people.

 Pot use may be priming brain for later opioid use

I appreciate Ricky's reply, yet I respectfully disagree.

In defense of my position, I agree that the current opioid crisis may in part be due to over-prescription, which does of course warrant serious attention. However, I suspect that the great bulk of this crisis has far more to do with the desire of addicts to seek out opioids any which way they can. Doctors for the most part are not prescribing medical marijuana to any measurable degree that would substantiate those findings. Instead more likely, addicts are intentionally abusing prescribed opioids not for pain relief, but merely to get 'high'.

And because of this abuse, some doctors may be reluctant to prescribe opioids in cases where real pain could be relieved! A real shame.

Particularly scary now are findings that earlier exposure to marijuana may be 'priming' the brain's pleasure seeking pathways for drugs such as heroin! Please refer to research by Dr. Yasmin Hurd of the Mount Sinai School of Medicine. And if that is not alarming enough, further studies suggest epigenetic modes may be priming offspring, and further generations, to have a desire for opioids. That is, vulnerability to addiction may be inherited by gene expression rather than gene alteration!

The implications are haunting. A whole generation of Americans, who essentially said "Yes" to marijuana and other drugs may have inadvertently 'primed' their offspring to have brains that are far more susceptible to becoming addicted with drugs such as heroin!