Increased Sensitivity to the Disinhibiting Effects of Alcohol in Binge Drinkers Cecile A. Marczinski, Stewart W. Combs, and Mark T. Fillmore University of Kentucky Heavy episodic alcohol use, or binge drinking, is a serious public health problem. Binge drinking is endemic in college students and has resulted in numerous alcohol-related tragedies, including acute alcohol poisonings, falls, and automobile collisions. Such negative outcomes might occur because binge drinkers are generally more impulsive, and this impulsivity might be exacerbated under alcohol. The purpose of this study was to examine this hypothesis by comparing the acute effects of alcohol on a cognitive measure of behavioral control in binge and nonbinge drinkers. The results indicated that binge drinkers act more impulsively and report feeling more stimulated under an acute 0.65 g/kg dose of alcohol compared to nonbinge drinkers. The present finding of a heightened disinhibitory reaction to alcohol in binge drinkers may help explain the link between impulsivity and problem drinking at a more fundamental level of behavioral control. Keywords: binge, alcohol, behavioral control, college students, impulsivity Heavy episodic or binge drinking has been argued to be the number one public health hazard and the primary source of pre- ventable morbidity and mortality for the more than 6 million college students in the United States (Wechsler, Dowdall, Daven- port, & Castillo, 1995). Epidemiological evidence has shown that binge drinking is widespread on college campuses, with almost half of the students reporting binge drinking. In addition, binge drinking has been associated with unplanned and unsafe sexual activity, assaults, falls, injuries, criminal violations, and automo- bile crashes (Wechsler et al., 1994; Wechsler, Dowdall, Daven- port, & Rimm, 1995; Wechsler, Dowdall, Maenner, Geldhill-Hoyt, & Lee, 1998; Wechsler, Lee, Kuo, & Lee, 2000). Binge drinkers are 14 times more likely to drive while impaired by alcohol than are nonbinge drinkers (Naimi et al., 2003), and driving while intoxicated is more directly associated with binge drinking than with chronic heavy drinking (Borges & Hansen, 1993; Duncan, 1997). Approximately 500,000 college students are injured and 1,700 die each year from alcohol-related injuries (Hingson, Heeren, Winter, & Wechsler, 2005). One potential explanation for the correlation between binge drinking and elevated alcohol- related injury risk (Cherpitel, 1993; Simons, 2003) is that binge drinkers are generally more impulsive and are more disinhibited by alcohol compared to more moderate drinkers. However, although there is intuitive appeal for the hypothesis that the impulsive response style of binge drinkers might be exacerbated by alcohol, the hypothesis lacks empirical support. In general, acute alcohol intoxication is associated with myriad negative outcomes, including violent crimes, injuries, and automo- bile accidents (Pernanen, 1976). Impaired self-control has long been associated with acute alcohol intoxication and is often a significant contributor to such negative consequences. A number of theories postulate that two distinct processes govern behavioral control: one that activates behavior and one that inhibits behavior (Fowles, 1987; Gray, 1976, 1977; Logan & Cowan, 1984; Patter- son & Newman, 1993; Quay, 1997). The two processes act in opposition to one another and the relative strength of each is assumed to determine behavioral control. Deficient behavioral inhibition is inferred by observations of overactive, impulsive behavior (Logan, Cowan, & Davis, 1984) and is considered to be a primary mechanism by which alcohol impairs self-control (Fill- more, 2003). In recent years, model-based assessments of behavioral inhibi- tion mechanisms have been used to study the acute effects of alcohol on the ability to inhibit inappropriate behavioral responses (Fillmore, 2003). Inhibitory processes normally serve to regulate behavior by suppressing or terminating prepotent (i.e., environ- mentally triggered) responses (Jentsch & Taylor, 1999). Thus, failures of inhibition result in impulsive and inappropriate actions (Fillmore, 2003). Several studies have examined the effects of alcohol on inhibitory processes using stop-signal and cued go/ no-go models that assess behavioral control as the ability to quickly activate and suddenly inhibit prepotent responses (Abroms, Fillmore, & Marczinski, 2003; de Wit, Crean, & Rich- ards, 2000; Fillmore & Vogel-Sprott, 1999; Marczinski & Fill- more, 2003, 2005; Mulvihill, Skilling, & Vogel-Sprott, 1997). These studies found that moderate doses of alcohol impaired the ability to inhibit a prepotent response. The impairing effects of alcohol were evident in spite of the relatively simple nature of the Cecile A. Marczinski, Stewart W. Combs, and Mark T. Fillmore, De- partment of Psychology, University of Kentucky. This research was supported by a grant from the Alcoholic Beverage Medical Research Foundation (A/B/M/R/F) to Cecile A. Marczinski and National Institutes of Health Grants R21 DA021027 and R01 AA12895 to Mark T. Fillmore. Correspondence concerning this article should be addressed to Mark T. Fillmore, Department of Psychology, University of Kentucky, Lexington, KY 40506-0044. E-mail: fillmore@uky.edu Psychology of Addictive Behaviors Copyright 2007 by the American Psychological Association 2007, Vol. 21, No. 3, 346 –354 0893-164X/07/$12.00 DOI: 10.1037/0893-164X.21.3.346 346