Objective: The primary purpose of this study was to provide a comprehensive assessment of the underlying factor structure of the Alcohol Dependence Scale (ADS). Secondary goals included assessing concurrent validity of the total ADS and subscales derived from the factor analyses with variables related to alcohol dependence and further evaluating the validity of two proposed dichotomously scored, reduced-item ADS measures.
Method: Responses to the ADS were obtained from participants who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for alcohol dependence in two large randomized clinical trials: COMBINE (Combining Medications and Behavioral Interventions Study; n = 1,335; 69% male) and Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity; n = 1,666; 75% male). Both exploratory and confirmatory factor analyses were conducted, and validity coefficients were obtained.
Results: Across samples, analyses supported a correlated, three-factor solution representing loss of behavioral control and heavy drinking, obsessive-compulsive drinking style, and psychoperceptual and psychophysical withdrawal. The ADS was significantly related to other measures of severity of dependence, craving for and preoccupation with drinking, temptation to drink and confidence in the ability to not drink in high-risk relapse situations, heavy and sustained drinking patterns, concerns about negative alcohol-related consequences, and awareness of problematic drinking.
Conclusions: These findings support a three-factor solution for the ADS and its ability to assess the construct of alcohol dependence in a reliable and valid manner. The 12-item reduced ADS measure (reflecting mostly dependence-related items), as opposed to the 9-item reduced ADS measure (generally excessive drinking items), provided validity coefficients comparable to the total, 25-item ADS.