Substance use disorders among mentally ill patients in a General Hospital in Sri Lanka: prevalence and correlates

Abstract

OBJECTIVES: To determine the prevalence, and demographic and clinical correlates of substance use disorders among the mentally ill. DESIGN AND SETTING: Cross sectional analytical study. Data were collected from consecutive patients treated at a Tertiary care Psychiatry Unit, Western Province, Sri Lanka using an interview schedule administered by a senior registrar in psychiatry. MEASUREMENTS: Diagnosis was based on ICD 10 criteria and the Clinician Rating Scale: Alcohol Use Scale (AUS) and the Drug Use Scale (DUS). The data were analysed using SPSS and WinPepi software programmes, utilising the chi squared, t test and median test. RESULTS: Among a sample of 325 patients, 66% were male; 33% were diagnosed with depressive disorder, 30% with schizophrenia, 23% with bipolar affective disorder and 13% with other disorders. Prevalence of comorbid substance use disorders was 43% (95% CI 38 - 49%). Alcohol was the commonest type of substance used. Those who had a comorbid substance use diagnosis were more likely to be male, have a lower educational level, be unemployed and have a poorer level of social support. They were also found to have poorer treatment adherence, increased number of hospital admissions and an increased association with episodes of violence. CONCLUSION: A significant proportion of patients were found to have a comorbid substance use diagnosis and associated complications. These findings have important implications for service provision for mentally ill patients with a comorbid substance use disorder.