Neural correlates of cross-commodity discounting in cocaine users and controls

s / Drug and Alcohol Dependence 140 (2014) e2–e85 e13 Alcohol demand indices predict outcomes among heavy-drinking young adults receiving a brief intervention Michael Bernstein2,1, J. Murphy3, J. MacKillop4, S. Colby1 1 Brown University, Providence, RI, United States 2 University of Rhode Island, Kingston, RI, United States 3 University of Memphis, Memphis, TN, United States 4 University of Georgia, Athens, GA, United States Aims: This study looked at the impact of baseline alcohol demand indices on alcohol consumption following a brief alcohol intervention. Methods: Participants (N=150, 43% female, 65% White, ages 17–20)were non-college-attending heavy episodic drinkers proactively enrolled in an intervention study that compared the efficacy of a motivational interview (MI) and relaxation training control (REL) on reducing alcohol use. Using self-reported data, we calculated participants’ average number of drinks per week and frequency of heavy drinking (HD, 5+ drinks) at baseline, a 6 week follow up (W6), and a three month (M3) follow up. At baseline, participants also completed a hypothetical alcohol purchase task, by indicating howmany alcoholic drinks they would purchase and consume across a range of prices ($0 to $20). From this task, five demand indices were calculated: Breakpoint (first price that completely suppresses consumption), Omax (maximum expenditure), Pmax (price atwhichdemandbecomeelastic), Intensity (consumption when drinks are free), and elasticity (slope of the demand curve, or sensitivity to price). Results: Hierarchical regressions controlling for gender and baselinedrinking showed that several demand indiceswerepredictive of drinking outcomes. Specifically, greater baseline Omax and intensity, and less elasticity predictedmoreW6 drinks/week in the MI condition. At M3, greater baseline breakpoint, Omax, intensity, and less elasticity predicted more drinks/week in the REL condition. Demand indices were predictive of W6 HD frequency in the MI condition and M3 HD frequency in the REL condition. Conclusions: The results suggest that elevated demand indices (except elasticity, which negatively predicted consumption) may be a risk factor of poor intervention response. However, there were differences according to condition, assessment period, and alcohol use measures. Financial support: The first author plans to complete the early career travel award application. Otherwise, there is currently no support. http://dx.doi.org/10.1016/j.drugalcdep.2014.02.056 Pair housing of juvenile male rhesus macaques: A pilot study Megan L. Bertholomey, Stephen Kohut, P. Fivel, Nancy K. Mello Alcohol and Drug Abuse Research Center, McLean Hospital/Harvard Medical School, Belmont, MA,