Nicotine, alcohol and drug dependence and psychiatric comorbidity

BACKGROUND: There is a well-recognised relationship between substance use disorders and other psychiatric disorders. This relationship has been well documented in a range of population-based studies. AIMS: This study aims to report on consumption patterns of and dependence on nicotine, alcohol and non-prescribed drugs and to report on the levels of psychiatric morbidity in these groups. METHOD: A national household study of psychiatric morbidity was conducted in England and Wales. Psychiatric assessment was based on the Clinical Interview Schedule-Revised (CIS-R). Measures of nicotine, alcohol and drug use and dependence were obtained. This paper compares the levels of psychiatric morbidity in the non-dependent and the nicotine-, alcohol- and drug-dependent cases. RESULTS: Twelve per cent of the non-dependent population were assessed as having any psychiatric disorder compared with 22% of the nicotine-dependent, 30% of the alcohol-dependent and 45% of the drug-dependent population. CONCLUSIONS: There is a clear relationship between dependence on nicotine, alcohol and drugs and other psychiatric morbidity.