Daily,high‐potency cannabis linked to first 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 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 percent of cases of first‐episode psychosis could be prevented, rising to 30.3 percent in London and 50.3 percent in Amsterdam.