The most informative time-frame appears to be within the past 6 months, as it is an optimal period to link alcohol consumption and alcohol-related problems (Hartley et al., 2004; Townshend & Duka, 2002, 2005; Weissenborn & Duka, 2003). Longitudinal studies of binge drinking have established that college students inconsistently report heavy episodic drinking across time (Schulenberg, O'Malley, Bachman, Wadsworth, & Johnston, 1996; Weingardt et al., 1998), so that a 2-week time-frame would underestimate binging prevalence (Vik, Tate, & Carrello, 2000). A recent study found that nearly one third of those classified as nonbinge drinkers (<5/4 drinks) during a 2-week time period in the middle of the month were classified as either binge drinkers (≥5/4 drinks, 1 or 2 times during the past 2 weeks) or frequent binge drinkers (≥5/4 drinks, ≥3 times in past 2 weeks) during the first 2 weeks of the month (LaBrie, Pedersen, & Tawalbeh, 2007). Use of a 2-week time period, therefore, would yield approximately 30% of heavy binge drinkers being excluded. A past 6 months time-frame for college samples captures the vacation time of the
