The Australian twin panel is a volunteer national twin sample maintained by the Australian National Health and Medical Research Council. Between 1980 and 1982, a questionnaire survey of adult twins registered with the panel produced replies from both members of approximately 3,800 twin pairs. Researchers conducted a followup telephone diagnostic interview survey between 1992 and 1994. The baseline questionnaire included questions about the respondents’ smoking histories. From the duration of smoking reported in these data, respondents who had smoked only once or twice apparently classified themselves as “never smokers.” Therefore, a positive response on the smoking section of the survey indicated a history of regular smoking rather than a history of experimentation with cigarettes. By combining these data with information about lifetime prevalence of alcohol dependence according to the American Psychiatric Association’s Diagnostic and Statistical Manual, Third Edition, Revised (DSM–III–R), as reported in the interview survey, the usual finding can be replicated, indicating a strong association between smoking and alcohol dependence.
