Effect of substance misuse in early psychosis

BackgroundStudies examining the temporal relationship between substance use and the onset of psychotic symptoms in schizophrenia are inconclusive.MethodThree groups of out-patients with schizophrenia were compared on onset of illness, symptoms and quality of life. Fifty-one subjects had no past or present history of substance misuse, 29 subjects had a history of past substance misuse occurring around the onset of their illness, and 33 subjects were currently misusing substances.ResultsCurrent substance misusers had poorer quality of life scores and less negative symptoms than the non-users. Those who had a past history of substance misuse had a significantly earlier age of onset than those with no substance use.ConclusionsAttention should be paid to substance misuse present at the first episode. Treatment for schizophrenia should begin even though a diagnosis of drug-induced psychosis cannot be ruled out.