Alcohol-related behaviors were assessed across increasing levels of severity. Drinking frequency was measured by asking: ‘How often do you use alcohol?’. Responses included ‘never’ (0), ‘once a year’ (1), ‘two to four times a year’ (2), ‘every other month’ (3), ‘once a month’ (4), ‘more than once a month’ (5), ‘once a week’ (6), ‘more than once a week’ (7) and ‘daily’ (8). Intoxication frequency was assessed by asking ‘How often do you use alcohol in such a way that you get really drunk?’. Responses were the same for drinking frequency. We transformed these ordinal measures into pseudo-continuous measures of the frequency of these behaviors in a typical 30-day period [9,48]. Finally, we included a count of life-time DSM-IValcohol dependence (AD) symptoms, assessed using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), a reliable and valid clinical instrument [49]. Each alcohol measure was log-transformed (left anchored at 1) to adjust for positive skew. Relationship status was measured by asking: ‘How long (in years) have you been together with your present partner?’. Respondents that indicated they were not in a
