0145-6008/(W2805-0018$03.00/0 Alcohousm: Clinical and Experimental Research Vol. 28, No.5. May Supplement 2004 \ Acute Alcohol Use and Suicidal Behavior: A Review of the Literature Cheryl J. Cherpitel, Guilherme L.G. Borges, and Holly C. Wilcox Background: Both acute and chronic use of alcohol are associated with suicidal behavior. However, the differing relationship of each component of alcohol use and possible causal mechanisms remain unclear. Methods: This article reviews and summarizes associations between acute alcohol consumption (with and without intoxication) and suicidal behavior (both completed suicide and suicide attempts) among adults 19 years and older, as presented in literature published between 1991 and 2001. Possible mechanisms and methodologic challenges for evaluating the association are also discussed. An application of a research design (the case-crossover study) that has the potential for addressing the effects of acute alcohol use over and above usual or chronic use is presented. Results: The majority of articles reviewed were restricted to descriptive studies that documented the prevalence of suicide completers or attempters who tested positive for alcohol use. A wide range of alcohol-positive cases were found for both completed suicide (10-69%) and suicide attempts (10-73%). Common methodologic limitations included the lack of control groups (for evaluating risk conferred by alcohol use), selection and ascertainment bias, and small sample sizes. The results of the case-crossover pilot study indicated substantially higher risk of suicide during or shortly after use of alcohol compared with alcohol-free periods. Conclusions: Although there is a substantial literature of published studies on acute alcohol use and suicidal behavior, the majority of studies focus on completed suicide and report prevalence estimates. Findings from such studies are subject to several possible sources of bias and have not advanced our knowledge of mechanisms in the association between acute alcohol use and suicidal behavior. The case- crossover design may help to overcome some limitations of these studies and facilitate evaluation of associations and possible causal mechanisms by which acute alcohol use is linked to suicidal behavior. Key Words: Acute Alcohol Use, Suicide, Attempted Suicide, Risk Factors, Case-Crossover Study. EGINNING WITH THE work of Emile Durkheim in the late 1800s, there has been a long tradition of sociological and epidemiologic studies on suicidal behavior. Contrary to Durhkeim's belief that alcohol consumption was only an individual and psychopathological factor in suicide, it is now viewed as a sociological phenomenon that has a deep impact on the variation found in suicidal behav- ior (Durkheim, 1966; Skog, 1991). Today, it is well accepted that both acute and chronic alcohol use are associated with suicidal beHavior (Berglund and Ojehagen, 1998), and From Alcohol Research Group (CJC), Berkeley, California; Instituto Nationalde Psiquiatria & UniversidadAutonoma Metropolitana-Xochimilco (GLGB), Col. San Lorenzo Huipulco, Mexico; and Johns Hopkins University (HCW), Bloomberg School of Public Health, Department of Mental Hygiene, Baltimore, Maryland. Received for publication January 21, 2004; accepted February 4, 2004. Supported, in part, by National Institute on Alcohol Abuse and Alcohol- ism National Alcohol Research Center Grant AA 05595. Reprint requests: Cheryl J. Cherpitel, DrPH, National Alcohol Research Center and Public Health Institute, Alcohol Research Group, 2000 Hearst Avenue, Berkeley, CA 94709; Fax.- 510-642-7175; E-mail: ccherpitel@arg.org. Presented at the University of Rochester Center for the Study and Preven- tion of Suicide and the National Institute on Alcohol Abuse and Alcoholism Alcohol and Suicide Workshop, Bethesda, MD, March 21-22, 2002. DOI:10.1097/01ALC.0000127411.61634.14 18S some consider this to be a_causal_re]atiojship (Brismar and Bergman, 1998). However, the causal mechanism for this relationship remains unclear (Hufford, 2001). This article addresses the association between acute alcohol consump- tion (with and without intoxication) and suicidal behavior, including both completed suicide and suicide attempts. We present a literature review of studies on the adult popula- tion (19 years and older) published during the years 1991 to 2001. The primary aims of this article are to assess what is known about th^jso^iation_betwe£D.. acute alcohol use .and suicidal behavior, discuss possible mechanisms of the asso- ciation and methodological challenges, suggest implications for future research, and describe the application of a method that used cases as their own controls to minimize potential bias from traditional case-control studies. Suicide is defined as "death arising from an act inflicted upon oneself with the intent to kill oneself (Rosenberg et al. 3 1988), whereas suicide attempt is defined as a "behavior with_a nonfatal outcome, for which there is evidence (either explicit or implicit) thaUhe person intended to kill, himself/ herself (O'Carroll et al., 1996). These definitions suggest that suicidal behavior implies a self-committed act carried outj#rih,,the intention toaieTWhen dealing with empirical studies, however, definitions become less stringent. In mor- B Alcohol Clin Exp Res, Vol 28, No 5, 2004: pp 18S-28S