First-episode drug-induced psychosis: a medium term follow up study reveals a high-risk group

Background Little is known about firstepisode drug-induced psychosis (F19.5). Objectives To examine the incidence, course, diagnostic stability, and outcomes of first-episode drug-induced psychosis (F19.5), and compare with first-episode schizophrenia (F20–21). Method An observational database was set up on all patients aged 16 and over with a first episode psychosis living in a county in Northern England between October 1998 and October 2005. Data were collected at presentation and annual follow-up. Information on patients with an ICD-10 diagnosis of either drug-induced psychosis (F19.5) or schizophrenia (F20) was compared. Results There was no significant difference between the two groups in levels of hospitalisation and violence. Patients with a drug-induced psychosis were more likely to lose contact with services, and a third developed a schizophrenia- spectrum disorder. Conclusions Increased attention should be paid to maintaining engagement with this high-risk group who have a high rate of transition to schizophrenia