Within the last year, 12 or more states have revised their marijuana laws or are considering doing so. As of 2018, 31 states, as well as the District of Columbia, Guam and Puerto Rico, had "comprehensive public medical marijuana cannabis programs." The criteria for a comprehensive program, as specified by the National Conference of State Legislatures and other organizations, are:
In addition, 15 states allow use of low THC, high cannabidiol (CBD) products for medical reasons or allow limited defenses. These 15 states are not considered to have "comprehensive" programs.
Nine states and the District of Columbia have legalized recreational use of marijuana: Alaska, California, Colorado, Massachusetts, Maine, Nevada, Oregon, Vermont and Washington.
The liberalization of state marijuana laws corresponds with public opinion. A 2018 poll by Quinnipiac University indicates that 93 percent of American voterås favored legalization of marijuana for medical purposes, and 63 percent favored legalization of marijuana without additional restraints.
Although state laws regarding marijuana use have become more permissive, federal laws have not. The federal Controlled Substances Act, passed in 1970, is still on the books. That law was passed as part of President Richard Nixon’s War on Drugs. Under the law, marijuana is a Schedule I drug, which means, from the perspective of the federal government, marijuana "has a high potential for abuse" and "the drug or other substance has no currently accepted medical use in treatment in the United States."
For a period during the Obama administration, however, the federal government relaxed enforcement of marijuana laws.
President Obama’s Deputy Attorney General, James Cole, wrote a "guidance" memo to United States Attorneys noting the changes in state laws and directing a more hands-off approach by the federal government "[i]n jurisdictions that have enacted laws legalizing marijuana in some form and that have also implemented strong and effective regulatory and enforcement systems to control the cultivation, distribution, sale and possession of marijuana."
Cole said, "[E]nforcement of state law by state and local law enforcement and regulatory bodies should remain the primary means of addressing marijuana-related activity."
In early 2018, Attorney General Jeff Sessions issued his own memo, rescinding the Cole Memo.
The Department of Justice said it was "announcing a return to the rule of law," adding that "Congress has generally prohibited the cultivation, distribution and possession of marijuana." U.S. Attorneys were directed "to enforce the laws enacted by Congress and to follow well-established principles when pursuing prosecutions related to marijuana activities."
Although Sessions has followed the Trump administration’s approach of undoing initiatives of the Obama administration, the federal government is not expected to markedly increase prosecutions of marijuana offenses.
The Institute of Medicine, part of the National Academies of Sciences, Engineering and Medicine, issued a report in 2017 on "The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research."
The report stated there was evidence to support use of cannabis or cannabinoids for treating multiple conditions.
On the negative side, the report said evidence suggested "cannabis use is likely to increase the risk of developing schizophrenia, other psychoses, and social anxiety disorders, and to a lesser extent depression."
Among the organizations issuing guidelines to physicians on the topic is the Federation of State Medical Boards. These guidelines were adopted in 2016 and have much in common with general medical standards:
Physicians should consult licensing boards and professional organizations for standards that may be applicable to them.
Jeff Atkinson is a professor for the Illinois Judicial Conference and has taught health care law at DePaul University College of Law in Chicago.