JAMA NetworkComorbidity and Coaggregation of Major Depressive Disorder and Bipolar Disorder and Cannabis Use Disorder in a Controlled Family Study

In this cross-sectional study of 586 probands and 698 first-degree relatives, cannabis use disorder and bipolar disorder II in probands were associated with an independent increase in risk of cannabis use disorder in relatives; bipolar disorder I and major depressive disorder in probands were not significantly associated with cannabis use disorder in relatives. The risk of cannabis use disorder was highest among relatives with both familial and individual history of bipolar disorder II.