Legalization status of cannabis affects people's views on benefits

Reviewed by Kate Anderton, B.Sc. (Editor)Dec 10 2019

Residents of states where cannabis has been legalized are more likely to believe it has beneficial effects - including health benefits in treatment of pain and anxiety or depression, reports a survey study in the Journal of Addiction Medicine, the official journal of the American Society of Addiction Medicine (ASAM). The journal is published in the Lippincott portfolio by Wolters Kluwer.

Our results show that residents of states where marijuana has been legalized for recreational use have an overall more favorable view towards potential benefits of marijuana use and were more likely to attribute benefits to marijuana use that are not supported by evidence."

Salomeh Keyhani, MD, MPH, University of California, San Francisco, and colleagues

They believe their findings raise concerns, at a time when the cannabis industry is growing rapidly and new products are being aggressively marketed.

Legalization status affects views on cannabis' benefits and risks

The researchers surveyed a nationally representative sample of approximately 9,000 US adults for their beliefs and opinions regarding cannabis. Viewpoints were compared for residents of states where is legal for recreational use, legal for medical use, or not legal.

"Overall, residents of states where marijuana was legalized for recreational purposes were more likely to endorse the belief that marijuana use had benefits compared to residents of other states," Dr. Keyhani and coauthors write. Most respondents believed that cannabis is beneficial for pain management: 73 percent in "recreationally legal" states, 67 percent in "medically legal" states, and 63 percent in "non-legal" states.

There's limited evidence to support the effectiveness of cannabis in pain treatment. More research is needed to establish whether cannabinoids are beneficial in the management of pain, Dr. Keyhani and coauthors write. In addition, the possible benefits of cannabinoid therapeutics cannot be extrapolated to untested and unregulated high-potency products currently marketed to the public.

Residents of states where cannabis is recreationally legal were also more likely to believe it has other unproven or unstudied benefits, such as relief from stress, anxiety, and depression. There's no evidence that cannabis can help treat these conditions – in fact, some data suggests cannabis use may adversely affect the management of anxiety and depression. Residents of recreationally legal states were more likely to say that smoking cannabis is "somewhat or much safer" than smoking tobacco – a belief unsupported by research evidence.

In all three groups of states, the majority of respondents believed that cannabis use carries a risk of developing addiction. Residents of recreationally legal states were more likely to believe cannabis use has certain other risks, including memory impairment and decreased intelligence and energy.

Not surprisingly, residents of recreationally legal states were more likely to report any type of cannabis use in the past year: about 20 percent, compared to 15 percent in medically legal states and 12 percent in non-legal states.

Cannabis is legal for recreational or medical purposes in 33 states and the District of Columbia. The trend toward legalization has been accompanied by rapidly increasing rates of recreational use, as well as cannabis use disorders. Dr. Keyhani and colleagues conclude: "The favorable views of residents in recreationally legal states are cause for concern given the tide of commercialization, growing number of unstudied high-potency products, and the favorable media coverage promoting use."

Richard Saitz, MD, MPH, Senior Editor of Journal of Addiction Medicine, points out that we have seen this situation before, and it did not go well. "In the early phases of the opioid epidemic, youth interpreted the fact that opioid medications were prescribed as a signal that they might be safe, and that perception was associated with misuse," Dr. Saitz comments. "Now, where cannabis is endorsed as 'medical' and where it is legal for non-medical use, people are more likely to perceive it as having benefits. As with opioids, we are now seeing an increase in cannabis use and cannabis use disorder."