New Study De-Links Cannabis Legalization With Increased Rates of Psychosis

Written by Lydia Kariuki

A recently published study has found that reported psychosis-related conditions did not increase in states that have legalized cannabis for medical and recreational use. The study which was conducted by researchers from the University of Philadelphia and  Stanford University was published in JAMA Open Network earlier this month.

This was a retrospective cohort study that analyzed commercial health insurance and Medicare Advantage claims in the period beginning on 1st January 2003 and ending on 31st December 2017. In total, 63 million individual claims were covered in the study. All beneficiaries were aged above 16 years and were eligible for insurance for at least one month in that period.

During the period, there were over 7 million psychosis-related diagnoses and over 20 million prescriptions for antipsychotic drugs. In the same period, a total of 29 states legalized cannabis for either medical and/or recreational use. The researchers found that states that had legalized cannabis in the period did not experience a statistically significant increase in psychosis-related diagnoses.

The results seem to contradict what had been earlier on predicted as a possible consequence of legalization. As NIDA puts it, regular consumption of high-potency marijuana could increase your odds of developing psychosis by up to five times! This is of course influenced by the age when marijuana is first used, frequency of use, and genetic predisposition.

Is it too early to predict the full mental health impact of cannabis legalization? For now, prudence is advised, especially for the younger demographics.

About the author

Lydia Kariuki