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Cannabis effects on human cognition, motivation, psychosis require more informed research

Current knowledge regarding cannabis effects on human behavior may not be applicable to current day use of the drug, according to researchers.

Colorado, Washington, Oregon and Alaska and Washington, D.C., recently passed laws legalizing cannabis use for recreational use, which could potentially trigger unintended consequences for health and social systems in the United States.

To inform political discourse with scientific evidence, Nora D. Volkow, MD, of the National Institute on Drug Abuse, and colleagues reviewed literature to identify what is known and not known regarding the effects of cannabis on human cognition, motivation and risk for psychosis.

The review highlighted the critical and broad role of the endocannabinoid system in the brain, and therefore the need to clarify what aspects of cannabis exposure confer greatest risk for the development of adverse outcomes, including cannabis use disorder, cognitive deficits, lack of motivation and psychosis.

Further, there are questions regarding policy that require research regarding advertising, cannabis use during pregnancy and its effect on fetus development, effects of secondhand cannabis smoke and more.

“If we stay the current course, we are likely to uncover effects that were rare in the past only because the use was not as widespread as that of legal drugs,” Volkow and colleagues wrote.

The current, limited knowledge of cannabis effects may only apply to ways in which the drug was previously used due to the changing landscape of cannabis use — such as higher tetrahydrocannabinol potency, new methods of ingestion and novel drug combinations — and changing cultural norms.

“The areas explored in this article, which reflect only a subset of the multiple effects of cannabis use on the brain and body, belie the ubiquity of the cannabinoid signaling system. Therefore, in addition to expanding our basic research efforts, we should try to learn as much and as rapidly as we can from the ongoing changes in local policies to minimize the harms and maximize the potential benefits,” the researchers concluded. – by Amanda Oldt

Disclosure: Volkow reports no relevant financial disclosures. Please see the full study for a list of all authors’ relevant financial disclosures.