Objective Life expectancy of psychiatric patients is markedly shorter compared to the general population, likely partly due to smoking or misuse of other substances. We investigated prevalence and correlates of substance use among psychiatric patients. Methods Within the Helsinki University Psychiatric Consortium Study, data were collected on substance use (alcohol, smoking, and illicit drugs) among patients with schizophrenia or schizoaffective disorder (n = 113), bipolar (n = 99), or depressive disorder (n = 188). Clinical diagnoses of substance use were recorded, and information on smoking, hazardous alcohol use, or misuse of other substances was obtained using questionnaires. Results One-fourth (27.7%) of the patients had clinical diagnoses of substance use disorders. In addition, in the Alcohol Use Disorders Identification Test, 43.1% had hazardous alcohol use and 38.4% were daily smokers. All substance use was more common in men than in women. Bipolar patients had the highest prevalence of alcohol use disorders and hazardous use, whereas those with schizophrenia or schizoaffective disorder were more often daily smokers. In regression analyses, self-reported alcohol consumption was associated with symptoms of anxiety and borderline personality disorder and low conscientiousness. No associations emerged for smoking. Conclusions The vast majority of psychiatric care patients have a diagnosed substance use disorder, hazardous alcohol use, or smoke daily, males more often than females. Bipolar patients have the highest rates of alcohol misuse, schizophrenia or schizoaffective disorder patients of smoking. Alcohol use may associate with symptoms of anxiety, borderline personality disorder, and low conscientiousness. Preventive and treatment efforts specifically targeted at harmful substance use among psychiatric patients are necessary.
Keywords: alcohol misuse; psychiatric care; smoking; substance use.