Marijuana Research at NIDA

What kinds of marijuana research does NIDA fund?

As part of its mandate to study drug abuse and addiction and other health effects of both legal and illegal drugs, NIDA funds a wide range of research on marijuana (cannabis); its main psychoactive ingredient, delta-9-tetrahydrocannabinol (THC); and chemicals related to THC (cannabinoids), including:

• Patterns and trends in marijuana use and attitudes, particularly among adolescents
• Short- and medium-term effects of THC on the brain and behavior; driving under the influence of cannabis
• Long-term effects of prenatal and adolescent cannabis exposure on brain development
• The development and impact of prevention programs on marijuana use
• Screening and brief assessment for marijuana abuse
• Medications and behavioral treatments for cannabis use disorder
• The working of the brain’s cannabinoid system, including its role in pain and HIV
• Potential therapeutic uses of THC and other cannabinoids in treatment of pain, HIV, and addiction
• Social, behavioral, and public health impacts of policy changes related to marijuana (i.e., “medical marijuana” and recreational legalization)

Does NIDA permit or fund studies on therapeutic benefits of marijuana?

Yes. Research suggests that THC and/or other cannabinoids (chemicals that act on the same receptors as THC in the brain and body) may have potential in the treatment of pain, nausea, obesity, wasting disease, addiction, autoimmune disorders, and other conditions. NIDA has provided and continues to provide funding for research related to therapeutic uses of cannabinoids, as it pertains to its mission, including studies on the use of THC and cannabidiol, another chemical constituent of marijuana, for the treatment of pain (as an alternative to opioid pain relievers) and addiction. For example, one currently ongoing study is examining the use of cannabidiol to reduce opioid craving in people with heroin addiction.

Research on therapeutic uses of marijuana or other chemicals in the marijuana plant could be supported by any Institute or Center at NIH where the disease, conditions, or affected organs are studied. For instance, the National Institute on Alcohol Abuse and Alcoholism is supporting a preclinical (animal) study on the use of cannabinoids to reduce neuroinflammation caused by HIV and exacerbated by alcohol use. Similarly, the National Cancer Institute is funding a preclinical study on the potential benefits of cannabinoids for the treatment of breast-cancer induced bone pain.

Note that the vast majority of research proposals received and funded by NIH on therapeutic benefits of cannabinoids have examined individual cannabinoid chemicals or, in a few cases, marijuana leaves delivered through some other means than smoking. Various factors make smoked marijuana therapeutically less promising than medications derived from cannabinoids, including the potential harmful health effects both short-lasting (sedation, cognitive and motor impairment) and long lasting (addiction, respiratory effects). Marijuana leaves contain numerous poorly understood or even toxic chemicals besides THC. It is also difficult to standardize dosages of a highly variable herb delivered in cigarettes or food (see NIDA’s fact sheet, “Is Marijuana Medicine”). A few medications derived from THC, however, are now FDA approved for relieving nausea associated with cancer chemotherapy and stimulating appetite in patients with wasting syndrome that often accompanies AIDS.

Whether submitted to NIDA or another NIH institute, research proposals to study therapeutic benefits of marijuana or one of its ingredients must meet the same accepted standards of scientific design as any other proposal and, on the basis of peer review, should meet public health significance and Institute priorities and be competitive with other applications that qualify for funding.

What is NIDA’s role in providing marijuana for research purposes?

In addition to funding research, NIDA also supports a drug supply program, which provides controlled substances (including research-grade marijuana) to researchers for scientific purposes. The marijuana supply program operates pursuant to the Single Convention on Narcotic Drugs, which requires each Nation to designate a single official source of marijuana for medicinal research. In the United States, NIDA has been designated the responsible agency.

NIDA contracts with the University of Mississippi to grow marijuana for use in research studies. The University designates a secure plot of land where marijuana crops are grown every few years, depending on demand. The marijuana is grown, harvested, stored, and made into cigarettes of varying THC content for research.[1] NIDA provides this marijuana (at no cost) both for NIH-funded projects and for non-NIH-funded projects that have been deemed scientifically valid by a Department of Health and Human Services (HHS) scientific review panel. Researchers do not need to be funded by NIH to obtain research-grade marijuana, but non-NIH-funded proposals must pass the HHS review process. (Applications approved by the HHS panel do not require additional approval from NIDA.)

The review process for non-NIH-funded proposals began in 1999, when HHS announced a series of steps to help facilitate research into the medical uses of marijuana and its specific chemical ingredients: http://grants.nih.gov/grants/guide/notice-files/not99-091.html. To date, 18 applications to obtain marijuana for medical research have been submitted by potential researchers not funded by NIH; of those, 15 received approval to obtain research-grade marijuana from NIH.[2]

How can researchers obtain marijuana from NIDA?

Studies not funded by NIH must go through the HHS review process. The HHS review committee consists of experts from across the Department of Health and Human Services with backgrounds relevant to the research being proposed.  Representatives’ expertise may range from expertise in drug development, to mental health and substance use disorders, to pain management, to alternative medicine (aligned to the goals of the proposal). The final decision as to whether or not to approve a proposal is based on the consensus of the experts on the review committee.

NIH-funded studies are not required to go through the HHS committee review, since grant applications already go through a rigorous, three-step NIH review process: (1) the NIH peer review system, which assesses the scientific and technical merit of all grant applications; (2) the Institute’s National Advisory Council, comprising eminent scientists as well as public members from the community; and (3) the Institute Director, who makes the final decision on the merit of an application for funding, based on peer review, public health significance, and Institute priorities.

Once an application has been scientifically evaluated and approved (whether through the HHS committee or through the NIH review process), researchers must then complete paperwork necessary for any projects involving both human participants and a Schedule I controlled substance: an Investigational New Drug application from the FDA and a DEA registration number for Schedule I substances.

When the above steps have been completed, investigators then contact the NIDA Drug Supply Program to place an order for marijuana with specific THC concentrations. The program official verifies that the application is complete (with all the above-mentioned steps fulfilled), and forwards the order on to the contractor responsible for shipping the marijuana.

For further information on this process, go to http://grants.nih.gov/grants/guide/notice-files/not99-091.html

Does NIDA have an official stand on legalization or decriminalization of marijuana for either recreational or therapeutic use?

No. NIDA is a scientific, not a policy-making agency (the same is true for the NIH as a whole). NIDA’s role is to conduct and support scientific research on drugs and drug abuse and to advise the public and policy-makers (such as Congress, the White House Office of the National Drug Control Policy, and the Drug Enforcement Administration) on the results of that research—with the goal of ensuring that the nation’s drug policies are informed by science.

That said, NIDA does closely watch legislative changes both nationally and at the state level, in order to anticipate and assess how changing drug policies—for instance laws around recreational or therapeutic use of marijuana—may affect rates of substance use and related public health issues that are our area of concern. The annual NIDA-supported Monitoring the Future survey of adolescent drug use and attitudes, for example, has over the past several years detected increasing use of marijuana by teens associated with a decreasing perception of marijuana’s harmfulness—a trend that may be linked to the public conversation about “medical marijuana” (and in some states legalization advocacy) over the same period of time. NIDA is encouraging its grantees to study effects of changing marijuana legislation, through administrative supplements to existing grants.

[1] In addition to analysis of grown material, the University of Mississippi facility also analyzes samples of confiscated marijuana that are provided by the Drug Enforcement Administration (DEA). These analyses provide a means of determining potency trends of illicit marijuana by determination of the THC concentrations and also of screening for herbicide contamination which might create a public health problem.

[2] The three remaining applications were returned to the applicants with the HHS review committee’s concerns and comments regarding study design and/or human subject protection. Applicants were also provided instructions on how to submit a revised proposal for additional review, although this option was not exercised in those three cases.