Cannabis and first-episode psychosis: Different long-term outcomes depending on continued or discontinued use. Schizophrenia Bulletin 37: 631–639

Objective: To examine the influence of cannabis use on long-term outcome in patients with a first psychotic episode, comparing patients who have never used cannabis with (a) those who used cannabis before the first episode but stopped using it during follow-up and (b) those who used cannabis both before the first episode and during follow-up.Methods: Patients were studied following their first ad-mission for psychosis. They were interviewed at years 1, 3, and 5. At follow-up after 8 years, functional outcome and alcohol and drug abuse were recorded. Patients were clas-sified according to cannabis use: 25 had cannabis use before their first psychotic episode and continuous use during fol-low-up (CU), 27 had cannabis use before their first episode but stopped its use during follow-up (CUS), and 40 never used cannabis (NU). Results: The 3 groups did not diffe