Poor medication adherence and risk of relapse associated with continued cannabis use in patients with first-episode psychosis: a prospective analysis
Schoeler T, Petros N, Di Forti M.
Lancet Psychiatry. 10 July 2017. DOI: http://dx.doi.org/10.1016/S2215-0366(17)30233-X
This study of almost 400 young people with first-episode psychosis showed that continued cannabis use predicted poor outcome, including risk of relapse, number of relapses, length of relapse, and care intensity at follow-up. Around 20-36% of the adverse effect of cannabis use was mediated by poorer medication adherence. The authors suggest more actively focusing on reducing cannabis use to achieve more effective treatment of first-episode psychosis.
http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(17)30233-X/fulltext