Assessment was based on lifetime prevalence. An alcohol dependence symptom score was obtained from nine items based on the substance dependence criteria from the Third Revised and Fourth Editions of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1987; 2000), as listed in Hansell et al. (2008). All items were scored Yes/No (1/0), with the exception of items 2 and 7, which were coded as three level ordinal measures (Item 2: no = 0, one unsuccessful attempt to cut down = 1, more than one unsuccessful attempt to cut down = 3, and Item 7: no = 0, a marked (but less than 50%) increase in the amount required to achieve the desired effect = 1, at least a 50% increase in the amount required = 2). Items were summed to obtain a single score. Distributions of alcohol dependence symptom scores are shown in Figure 1. Approximately 34% of the sample had positive responses for 3 or more criteria, consistent with being classified as alcohol dependent.
