Cognitive impulsivity and HIV serostatus in substance dependent males

AbstractHIV-seropositive (HIV1) drug users show impaired performance on measures of integrity of prefrontal–subcorticalsystems. The Iowa Gambling Task (GT) is mediated primarily through ventromedial–prefrontal systems, and poorperformance on this measure (“cognitive impulsivity”) is common among substance dependent individuals (SDIs) aswell as patients with disease involving prefrontal–subcortical systems (e.g., Huntington disease). We hypothesizedthat HIV1 SDIs might be more vulnerable to cognitive impulsivity when compared with HIV-seronegative (HIV2)SDIs because recent studies report evidence of additive effects of HIV serostatus and drug dependence on cognition.Further, working memory is considered a key component of GT performance and is reliably impaired among HIV1SDIs compared to controls. We administered the GT to 46 HIV1 and 47 well-matched HIV2 males with a past orcurrent history of substance dependence. In addition, we evaluated correlations between subjects’ scores on the GTand on a delayed nonmatch to sample (DNMS) task in order to test if working memory deficits accounted forcognitive impulsivity among the HIV1 subjects. The HIV1 subjects performed significantly more poorly on theGT compared to the HIV2 group but this effect could not be explained by working memory deficits. Implicationsof these findings for future basic and applied studies of HIV and substance dependence are discussed.(JINS, 2004, 10, 931–938.)Keywords: HIV, Prefrontal cortex, Addiction, Drug abuse, Gambling task