Prevalence and patterns of substance misuse in schizophrenia

Abstract

Aims and Method To identify the prevalence and patterns of substance misuse in patients with schizophrenia in a catchment population in Dublin, and to compare this with that of a control group from general practice. Ninety-nine patients and 75 controls were interviewed using a semi-structured technique. Urine samples were obtained from all patients and controls were analysed for illicit substances. Results Prevalence of illicit substance and alcohol misuse was similar among patients (illicit substances, 45%; alcohol, 33%) and controls (illicit substances, 43%; alcohol, 25%). Patterns of substance misuse were similar, apart from ecstasy, which was used more commonly by controls. Discrepancies were found between histories of drug use and urinalysis. Clinical Implications Illicit substance misuse in patients with schizophrenia may mirror usage in the general population, rates of misuse reflecting cultural factors rather than illness and patterns of misuse reflecting geographical variations in the availability of drugs. A combination of screening methods is more effective than the use of a single source of information.