1. DIFFERENCES IN ALCOHOLISM RISK FACTORS BETWEEN AFRICAN AMERICANS AND CAUCASIANS WITHIN AN ALCOHOL-CHALLENGE PARADIGM S.L. Pedersen & D.M. McCarthy University of Missouri Introduction  Compared to Caucasians, African Americans have lower lifetime prevalence of most psychiatric disorders, including alcohol use disorders (Breslau et al., 2005).  African Americans also exhibit different drinking patterns than Caucasians (e.g. Bachman et al., 1991; Warheit et al., 1996; Dawson, 1998):  Initiate drinking later and increase use slower  Higher rates of abstinence  Increased persistence for alcohol use disorders once they develop  Numerous risk factors have been identified for Caucasian heavy drinking and alcohol-related problems.  Alcohol expectancies (see Goldman et al., 1999; Jones et al., 2001 for reviews)  Disinhibition/impulsivity (Sher & Trull, 1994),  Response to alcohol (e.g., Schuckit & Smith, 2001)  Additionally, in Caucasian samples, disinhibition and alcohol expectancies have been found to influence response to alcohol (Erblich & Earlywine, 2003; Brunelle et al., 2004; Schuckit, 1998).  However little research has tested potential explanations for racial differences in alcohol use.  This study tests group differences in 1) alcohol expectancies, 2) disinhibition, and 3) response to alcohol as potential explanations of drinking differences between African Americans and Caucasians. Study Hypotheses:  We tested mean differences between African Americans and Caucasians on alcohol use and risk factors for heavy use. African Americans should exhibit:  Lower positive alcohol expectancies.  Lower levels of disinhibited personality traits.  Higher self-reported sensitivity to alcohol.  We hypothesized that African Americans would experience less stimulation and more sedation from alcohol following the alcohol challenge. Discussion  This study tested two potential models for explaining differences in heavy alcohol use between Caucasians and African Americans.  A mean difference model, where lower levels of drinking in African Americans is due to lower levels of common risk factors for alcohol involvement (alcohol expectancies, disinhibition).  An alcohol response model, where African Americans exhibit lower stimulation and increased sedation following alcohol administration.  Results of the current study are consistent with a mean difference explanation, identified in prior research (McCarthy et al., 2001).  African Americans reported lower positive alcohol expectancies.  African Americans reported lower levels of four disinhibited personality traits.  Additionally, results from self-report suggested that African Americans reported greater sensitivity to the sedating effects of alcohol during their heaviest drinking period. This increased sensitivity would suggest reduced risk.  Contrary to hypothesis, alcohol challenge results indicated that African Americans experienced increased stimulation from alcohol on the ascending limb compared to Caucasians.  Prior research in Caucasian samples indicated that increased stimulation on the ascending limb is associated with increased risk of alcoholism (e.g., Newlin & Thompson, 1990).  As our African American sample experienced greater stimulation but reported lower drinking, our alcohol challenge results may indicate that response to alcohol may function differently for African Americans.  It may also be that genetic differences in the alcohol metabolizing enzymes (e.g., ADH polymorphisms) account for group differences in alcohol challenge results.  Data collection for this project is currently ongoing.  Future analyses will test for potential differences in mediation/moderation of risk between African Americans and Caucasians (e.g. religiosity). Acknowledgements Supported by NIAAA grants R21 AA015218: PI Denis M. McCarthy; T32 AA13526 ; PI Kenneth Sher. Method Participants  178 participants (mean age = 21.87, SD = 1.23; 43% male) completed the first visit of a two part alcohol- challenge study.  131 participants completed the second laboratory visit (105 African Americans, 26 Caucasians).  Participants were recruited from posted advertisements. Measures  Demographics.  Alcohol Use. Past month quantity, frequency, and frequency of heavy drinking.  Disinhibition. Negative Urgency, lack of Premeditation, lack of Perseverance, Sensation Seeking (UPPS: Whiteside & Lynam, 2001) and Positive Urgency (Cyders et al., 2007).  Alcohol expectancies (Goldman et al., 1997).  Subjective Response  Retrospective Sensitivity. Number of drinks required to feel an effect after first 5 drinking occasions and during period of heaviest drinking (SRE: Schuckit et al., 1997)  Acute Response. Stimulation and sedation assessed across ascending and descending limbs (BAES: Martin et al., 1993) Procedure  Visit 1: Questionnaires.  Visit 2: Alcohol challenge.  Completed baseline measurements (BAES, BAC)  Dosed with.72 g/kg ethanol at 9:00 am  Measurements repeated at 15, 30, 45, 60, 90, 120, and 150 minutes after alcohol administration. Analytic Plan  Test mean differences in alcohol use, retrospective sensitivity to alcohol, alcohol expectancies, and disinhibition.  Fit separate linear growth models for acute response on ascending and descending limbs using Mplus 4.2 (Muthén & Muthén, 2007).  Use these models to examine associations between racial group and acute response to alcohol. Results Mean Level Racial Differences  Drinking Behavior  African Americans reported lower levels of recent alcohol use:  past month (t = -4.41, p <.001)  typical quantity/frequency of drinking (t = -2.47, p <.05)  Alcohol Expectancies  African Americans reported lower positive alcohol expectancies (t = -3.56, p <.001).  Disinhibition  African Americans reported lower levels of disinhibited personality traits:  urgency (t = -2.14, p <.05)  sensation seeking (t = -3.20, p <.01)  lack of perseverance (t = -2.40, p <.05)  positive urgency (t = -3.11, p <.01)  Retrospective Sensitivity to Alcohol  African Americans reported increased sensitivity to alcohol during their heaviest drinking period (t = -3.85, p <.001). Acute Response to Alcohol  African Americans experienced increased stimulation from alcohol on the ascending limb (ß = -.32, p <.01).  There were no differences between groups in acute sedation on the descending limb. Intercept -.32 p <.01.08 ns -.05 ns.07 ns -.26 p <.05 RaceGender BAES Stim Slope