The alcohol dependence symptoms (ADsx) measure was the count of the number of lifetime DSM-IV criteria that respondents endorsed from the SSAGA (Bucholz et al., 1994). Responses ranged from 0 to 7. ADsx was natural log-transformed after adding 1 to adjust for the positive skew and to retain participants who endorsed zero symptoms. Individuals who never initiated alcohol use were coded as missing (n = 35).
