The significance of number of days abstinent but not lifetime consumption or duration of AUD as a moderator of ES distribution could be interpreted as support for a model in which alcohol-related brain damage occurs primarily during intoxication, not withdrawal (Crews and Nixon, 2009). The ability of the brain to heal itself after a sizable but time-limited dose of alcohol is supported by an animal model of binge drinking showing complete normalization of ventricular dilation after 7 days of recovery (Zahr et al., 2010). An alternative explanation is that duration of abstinence possessed greater predictive power than lifetime consumption or AUD duration because it was quantified with greater precision, thereby introducing less random error into analyses. Although the reliability and validity of lifetime consumption and AUD duration have proven adequate in most cases (Jacob et al., 2006; Koenig et al., 2009), these measures necessarily entail estimation and interpolation in the participant’s self-report. Many study participants resided in controlled environments with supervised abstinence prior to data collection, a factor likely to increase the accuracy of the abstinence variable.
