Daily, high‐potency cannabis use linked to first‐episode psychosis

Daily use of marijuana (cannabis) is associated with a greater than three times increased risk of psychotic disorder compared to never users, according to a study published in the March 19 issue of Lancet Psychiatry . This risk increased to nearly five times if high‐potency cannabis was used. Across the 11 sites included in the study, if high‐potency cannabis were not available, 12.2% of cases of first‐episode psychosis could be prevented, rising to 30.3% in London and 50.3% in Amsterdam.