Alcohol Mixed with Energy Drink Use as an Event-Level Predictor of Physical and Verbal Aggression in Bar Conflicts Kathleen E. Miller, Brian M. Quigley, Rebecca K. Eliseo-Arras, and Natalie J. Ball Background: Young adult use of alcohol mixed with caffeinated energy drinks (AmEDs) has been globally linked with increased odds of interpersonal aggression, compared with the use of alcohol alone. However, no prior research has linked these behaviors at the event level in bar drinking situations. The present study assessed whether AmED use is associated with the perpetration of verbal and physical aggression in bar conflicts at the event level. Methods: In Fall 2014, a community sample of 175 young adult AmED users (55% female) com- pleted a web survey describing a recent conflict experienced while drinking in a bar. Use of both AmED and non-AmED alcoholic drinks in the incident were assessed, allowing calculation of our main predic- tor variable, the proportion of AmEDs consumed (AmED/total drinks consumed). To measure perpe- tration of aggression, participants reported on the occurrence of 6 verbal and 6 physical acts during the bar conflict incident. Results: Linear regression analyses showed that the proportion of AmEDs consumed predicted scores for perpetration of both verbal aggression (b = 0.16, p < 0.05) and physical aggression (b = 0.19, p < 0.01) after controlling for gender, age, sensation-seeking and aggressive personality traits, aggressive alcohol expectancies, aggressogenic physical and social bar environments, and total number of drinks. Conclusions: Results of this study suggest that in alcohol-related bar conflicts, higher levels of young adult AmED use are associated with higher levels of aggression perpetration than alcohol use alone and that the elevated risk is not attributable to individual differences between AmED users and nonusers or to contextual differences in bar drinking settings. While future research is needed to identify motiva- tions, dosages, and sequencing issues associated with AmED use, these beverages should be considered a potential risk factor in the escalation of aggressive bar conflicts. Key Words: Aggression, Alcohol, Energy Drinks, Bar Conflict. A LCOHOL-RELATED AGGRESSION is a significant threat to the health and well-being of U.S. young adults, with 25 to 40% experiencing some type of physical aggression annually (Graham and Homel, 2008; Quigley and Leonard, 2005). Laboratory studies consistently demonstrate that alcohol exacerbates aggression, both by lowering the provocation threshold at which it is triggered (Ito et al., 1996) and by escalating its severity as the level of intoxication increases (Giancola et al., 2011). Alcohol increases physio- logical arousal, impairs inhibitory control, and narrows attentional focus, creating a state of “alcohol myopia” wherein the drinker focuses only on the most salient, typi- cally instigatory environmental cues at the expense of less salient, typically inhibitory cues (Steele and Josephs, 1990). Collectively, these psychopharmacological effects increase the likelihood that a drinking individual’s reaction to a potentially provocative situation will include some form of verbally or physically aggressive response. Emerging evidence now suggests that the long-standing problem of alcohol-related aggression may have begun to intersect with a relatively new practice increasingly embed- ded in young adult recreational drinking culture. Cocktails mixing alcohol with caffeinated energy drinks (AmEDs), most notably Red Bull vodkas and Jagerbombs, have risen rapidly in popularity since their introduction in the early 2000s, becoming a staple of the contemporary U.S. bar land- scape. Annual prevalence of young adult AmED use now stands at 39% among college students and 34% among non- students of comparable age (Monitoring the Future Study; Johnston et al., 2014). The practice is worrisome because these beverages have been globally linked with a constella- tion of risk-tolerant attitudes (Miller, 2008b) and problem behaviors, ranging from hazardous drinking and alcohol dependence to driving while intoxicated and unsafe sex (Arria et al., 2010; Miller, 2012; O’Brien et al., 2008). While most of this early research did not examine the co-occurrence From the Research Institute on Addictions (KEM, BMQ, RKE-A, NJB), University at Buffalo, The State University of New York, Buffalo, New York. Received for publication July 27, 2015; accepted September 30, 2015. Reprint requests: Kathleen E. Miller, PhD, Research Institute on Addictions, University at Buffalo, 1021 Main Street, Buffalo, NY 14203; Tel.: 716-887-2588; Fax: 716-887-2215; E-mail: kmiller@ria.buffalo.edu Copyright © 2016 by the Research Society on Alcoholism. DOI: 10.1111/acer.12921 Alcohol Clin Exp Res, Vol 40, No 1, 2016: pp 161–169 161 ALCOHOLISM:CLINICAL AND EXPERIMENTAL RESEARCH Vol. 40, No. 1 January 2016