Even scientists who wish to conduct research on cannabis in states where it is legal may risk their DEA licenses or federal funding by performing that research. All cannabis used for government-sanctioned research must be obtained through the NIDA Drug Supply Program, and NIDA’s sole source of marijuana is the University of Mississippi. As a result, researchers are limited in the types, strains, compositions, and forms of the cannabis that they receive to study.
The National Academies of Sciences, Engineering, and Medicine (NASEM) have identified three significant barriers to cannabis research, all of which are a direct result of the current federal laws related to cannabis. The NASEM committee found that “[i]nvestigators seeking to conduct research on cannabis or cannabinoids must navigate a series of review processes that may involve the National Institute on Drug Abuse (NIDA), the U. Researchers are not permitted, for example, to study the actual cannabis being sold quasi-legally across the majority of states.
Despite these local laws, possession and use of cannabis remains illegal under federal law pursuant to the Controlled Substances Act of 1970, under which it is classified as a Schedule I drug. implemented strong and effective regulatory and enforcement systems to control the cultivation, distribution, sale, and possession of marijuana," except where a lack of federal enforcement would undermine federal priorities, because of its “expectation that states and local governments that have enacted laws authorizing marijuana-related conduct will implement strong and effective regulatory and enforcement systems that will address the threat those laws could pose to public safety, public health, and other law enforcement interests.” In January 2018, the Cole Memorandum was rescinded by Attorney General Jeff Sessions during Donald Trump’s presidency.
Research Obstacles One hurdle cannabis researchers are facing is the legality – or lack thereof – of conducting their research. Drug Enforcement Administration (DEA), institutional review boards, offices or departments in state government, state boards of medical examiners, the researcher's home institution, and potential funders.”  The long and arduous application process serves as a barrier to research, and has been found to discourage cannabis researchers from applying for grant funding or pursuing additional research efforts. Secondly, the NASEM committee found that the barriers to cannabis supply significantly limited the amount and scope of research that is taking place.
Because the vast majority of available cannabis has not been subject to evidence-based and peer reviewed research, clinicians do not have the best tools to treat their clients.
Notwithstanding the need for additional research, NAADAC recognizes and accepts the findings of the November 2016 Surgeon General’s report on Facing Addiction in America 2016, as well as the January 2017 NASEM report cited above.
Thirdly, the NASEM committee found that there are limited funding opportunities through the National Institute of Health (NIH) and NIDA. Increased funding opportunities are necessary for adequate research to take place.
Accordingly, it is NAADAC’s position that the federal government must issue new guidance to provide legal protections for scientists studying cannabis and provide increased funding for this research to take place.
 In 2016, DEA put into place a mechanism by which other private entities could apply for permission to cultivate and distribute research-grade cannabis. Retrieved from Pacula RL, Powell D, Heaton P, Sevigny EL.
Despite dozens of applications being submitted, as of December 2018, no other facilities have been approved. “DEA decision keeps major restrictions in place on marijuana research.”  National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Board on Population Health and Public Health Practice; Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda. Assessing the effects of medical marijuana laws on marijuana use: the devil is in the details.