The measurement of alcohol dependence and impaired control in community samples.

The concept of the Alcohol Dependence Syndrome has been influential in the field of alcohol studies in the 1980s. The Severity of Alcohol Dependence Questionnaire (SADQ) is one of a generation of alcohol problem scales developed to measure degree of dependence rather than presence or absence of 'alcoholism'. This paper describes the development of a form of the SADQ for community samples of drinkers (SADQ-C) and its relationship to a brief scale designed to measure impaired control over drinking. In a sample of 52 problem drinkers, SADQ and SADQ-C correlated almost perfectly (r = 0.98). In a larger sample of 197 attenders at a controlled drinking clinic, Principal Components Analysis revealed one major factor accounting for 71.7% of the total variance. High internal reliability was indicated with a Cronbach's Alpha of 0.98. Application of this instrument in a random survey of Western Australian households is then described. It was necessary to remove items relating to 'reinstatement of dependence' for this sample. A single major factor was identified by principal components analysis, accounting for 69.1% of the total variance. In both the clinic and the community samples SADQ-C scores correlated highly with Impairment of Control scores. The findings are interpreted as supporting the view that there is a single dimension of alcohol dependence upon which all persons who drink alcohol with any regularity may be located.