Cognitive function in HIV-1-infected drug users.

Loss of cognitive ability, the most common neuropsychological complication in HIV-1 disease, may influence compliance with treatment and has been associated with decreased functional capacity, as well as an increased risk of mortality. In HIV-1-infected drug users, cognitive impairment affecting attention, memory, planning of complex tasks, information processing, and motor processes, has been reported, similar to findings in predominantly HIV-1-infected nondrug-using cohorts. The issue of whether early signs of cognitive dysfunction can be identified in asymptomatic HIV-1-infected drug users remains controversial. Evaluation of potential confounding factors, such as drug abuse, age, education, nutritional status, which may influence cognitive function, is essential for determining the dominant cause of neuropsychological abnormalities. There is evidence for a time-limited, protective effect against the development of AIDS dementia with zidovudine therapy. The potential ability of other therapies (e.g., antioxidants, B-complex vitamins) to prevent neuronal damage and protect the brain remains to be determined.