However, with medical marijuana legal in 29 states and the District of Columbia, I feel that psychologists in those jurisdictions have an ethical duty to be familiar with medical marijuana, including potential uses to address problems their patients may have with numerous medical issues.
WebMD is one good source of information, including a recent posting on the use of marijuana in pain management (https://www.webmd.com/pain-management/features/medical-marijuana-uses). For most people, marijuana increases appetite, decreases nausea, reduces falling, improves sleep, decreases depression, decreases pain and has other benefits.
A given patient could spend months or years in psychological treatment if the psychologist does not assess for potential benefits from medical marijuana – or any other medication that might be helpful. Marijuana (cannabis) was a patent medication available over the counter until 1937 in the United States.
For a lot of information about the history of marijuana as medicine, one can download a free copy of by far the best book on the subject, Licit and Illicit Drugs by Ed Brecher and the editors of Consumer Reports published in 1972 (http://www.druglibrary.org/schaffer/library/studies/cu/cumenu.htm).
While the Controlled Substances Act places any form of THC (the active ingredient in marijuana) in Schedule I, as having NO medical use, the Drug Enforcement Administration (DEA) places synthetic THC (Marinol, dronabinol) in Schedule III, meaning that it can be prescribed by any physician for any medical purpose.
Every psychologist should watch the videos in which Sanjay Gupta, M.D., CNN’s medical expert, lauds the success of CBD in markedly reducing seizures in children. They’re on YouTube and could be found by searching for Dr. Gupta’s name.
One of the many good websites for information about marijuana/cannabis is https://www.thecannabist.co.
Andrew W. Kane, Ph.D., is a clinical, consulting and forensic psychologist in Milwaukee, Wisc. He served on the Wisconsin State Citizens Council on Alcohol and Other Drug Abuse in the 1970s (appointed by governors of both parties) and has read dozens of books and many hundreds of articles about marijuana/cannabis since 1970. He also served on the Wisconsin Psychological Association’s ethics committee for 10 years. His email is: firstname.lastname@example.org