Age at first drink excluded small sips or tastes. Past-year volume of ethanol intake (Dawson, 2003) was set to the larger of the sum of four beverage-specific volumes or the volume for all beverage types combined. Interval since onset of dependence is the difference between age at baseline and age at first onset of dependence. Severity of dependence as represented by number of Wave 1 past-year AUD symptoms reflected positively endorsed items out of a list of 34 that included severe headaches following drinking or when trying to cut down. Number of episodes of dependence was used to identify individuals with prior episodes of dependence.
