Cognitive Training to Reduce Impulsivity in HIV-infected Cocaine Users

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Project Summary Of the 1.2 million Americans living with HIV, over half experience neurocognitive impairments (NCI) that adversely affect daily living and are predictive of increased morbidity and mortality. HIV-infected individuals who are addicted to stimulant drugs like cocaine are at even higher risk for NCI, which contributes to impulsive decision making, and engage in high rates of risky behaviors that are associated with both poor clinical outcomes and HIV transmission to others. Delay discounting, a key aspect of impulsivity, describes the tendency to devalue a reward as the delay to its receipt increases. Individuals addicted to drugs tend to prefer smaller, immediate rewards over larger, delayed rewards. Excessive discounting is associated with a wide range of other health risk behaviors, including risky sex. The Competing Neurobehavioral Decision Systems model posits that excessive discounting results from greater relative strength of the impulsive system over the executive control system. Our own work suggests that HIV infection modulates the effect of cocaine on brain functioning in the executive control network during delay discounting. Prior research supports a robust association between excessive discounting and working memory impairment. As a core executive function that supports self-regulation, working memory is theoretically an intervention target for HIV risk reduction. Computerized working memory training has been shown to decrease delay discounting in stimulant users, but it has not yet been tested in HIV-infected drug users. The proposed R21 study will test the preliminary efficacy of a computerized cognitive training program to improve working memory and reduce delay discounting in HIV- infected cocaine users. Using a randomized trial design, we will assign 50 participants to either the experimental cognitive training condition or an attention-matched control condition. Participants will complete 16 sessions in 8 weeks, with assessments at baseline, post-training, and 1-month follow-up to evaluate intervention effects. We hypothesize that cognitive training will, relative to the control condition, lead to greater improvements in working memory and reductions in delay discounting. We will also examine change in HIV risk behaviors (cocaine use, risky sex, and medication adherence). Results will support an R01 application for a larger scale trial to rigorously test the impact of cognitive training on HIV-related behavioral and clinical outcomes. This innovative line of research has important translational implications for HIV clinical practice, including dissemination in resource-limited settings with few neuropsychology specialists. This proposal directly advances a high priority topic for AIDS-designated funding by testing a novel treatment for HIV- associated NCI in drug users. By focusing on a high-risk population that continues to drive HIV transmission, this research has strong potential to improve neurobehavioral functioning in HIV-infected persons, and ultimately to reduce the incidence of new HIV infections.