The effect of recent stimulant use on sustained attention in HIV-infected adults.

Evidence suggests that stimulant use may exacerbate the deleterious cognitive effects of HIV, and that it has similar neuropathological consequences. In the current study, we examined the effect of recent stimulant use on sustained attention in adults infected with HIV. The sample consisted of 23 non-drug users and 17 stimulant users (cocaine and/or methamphetamine), all who were HIV-positive. Drug use was determined via urine toxicology. Sustained attention was assessed with the Conners' Continuous Performance Task--second edition (CPT-II). Groups were compared on overall performance variables, as well as patterns of performance across time. Compared to the non-drug users, stimulant users showed a gradual increase in reaction time variability and omission errors. Stimulant users' scores indicated impaired vigilance relative to an age and gender-matched normative sample. The groups were equivalent on other measures of attention, global neuropsychological functioning, mood, and demographic variables. The results indicate that recent stimulant use among HIV-infected adults adversely affects sustained attention.