Cannabis Linked to Bipolar Disorder Risk in Longitudinal Studies

A systematic review published in the Journal of Affective Disorders analyzed longitudinal studies tracking individuals without prior bipolar disorder diagnoses. Researchers found that cannabis users subsequently developed more bipolar diagnoses and reported increased manic or hypomanic symptoms compared to non-users. While the association is noteworthy and warrants clinical attention, particularly for at-risk populations, observational data cannot establish direct causation. Healthcare providers should consider cannabis use history when evaluating patients for mood disorders, and individuals with family histories of bipolar disorder should be counseled about potential risks.