Relationship between substance abuse and first-episode psychosis - a South African perspective

Abstract

Background. Co-morbidity between substance abuse and psy- chotic disorders is high. Few studies have examined therelationship between first-episode psychosis and substance abuse. Several questions emerge from this common relationship and many of them remain unanswered.

Objectives. To determine the effect of substance abuse on psychosis in terms of onset, duration, severity of symptoms, use of medication and outcome.

Method. Thirty - three subjects with first-episode psychosis, as well as primary caregivers, were interviewed re g a rding substance abuse and its relation to illness. Thirty-six control subjects were also interv i e w e d .

Results. Twenty-seven per cent of subjects abused substances in the 3 months before onset of illness, and 77.8% of the abusers w e re male. Subjects in the first-episode psychosis group were m o re likely to choose cannabis as their substance of abuse than c o n t rols. They also started abusing substances at a younger age than controls. Subjects with first-episode psychosis who abused substances presented at an earlier age than non-abusers. Substances affected symptoms at baseline presentation .

Conclusions. Substance abuse has a significant impact on first- onset psychosis as far as age of onset and symptom severity are c o n c e rned. Subjects with an underlying vulnerability to psychosis seem to start abusing substances at an earlier age than the general population. Males are more likely to abuse substances than females.