Experts warn against cannabis use during adolescence, pregnancy, and while driving

Their recommendations are based on an “umbrella review” of 101 meta-analyses on cannabis and health. Umbrella reviews synthesize previous meta-analyses and provide a high-level summary of evidence on a particular topic.

To address this, an international team of researchers set out to assess the credibility and certainty of over 500 associations reported between cannabis and health in 50 meta-analyses of observational studies and 51 meta-analyses of randomized controlled trials, pooling data from hundreds of individual studies.

Based on at least suggestive level evidence in observational studies and moderate certainty evidence in trials, the researchers found an increased risk of psychosis associated with cannabinoids in the general population.

Specifically, cannabis use was associated with psychosis in adolescents (when brain development is still taking place), and with psychosis relapse in people with a psychotic disorder.

Reference: Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomized controlled trials and observational studies, The BMJ, DOI 10.1136/bmj-2022-072348