Objective: The authors' goal was to study the potential effect on cognitive function of an interaction of HIV infection and a history of alcohol abuse.
Method: The subjects were 30 HIV-negative and 50 HIV-positive men with and without a past history of alcohol abuse. Thirty-three of the men (12 HIV negative and 21 HIV positive) had a past history of alcohol abuse, and 47 (18 HIV negative and 29 HIV positive) had never abused alcohol. Each subject's history of alcohol use was obtained by using a syndromal approach based on the Structured Clinical Interview for DSM-III-R and a quantitative approach. Each subject was given a battery of neuropsychological tests assessing verbal reasoning, reaction time, intelligence, memory, and dexterity. The subjects were then compared on a summary neuropsychological impairment rating.
Results: There were no significant differences in CD4 level, age, education, depression, anxiety, or other drug abuse history between the HIV-positive and HIV-negative groups with and without a history of alcohol abuse. Significant effects on cognitive function were found for past alcohol abuse and HIV infection, with significant interactions in verbal reasoning, auditory processing, and reaction time. This demonstrates that HIV infection and a history of alcohol abuse have independent effects on some aspects of higher cognitive function but may have synergistic effects on other cognitive domains. In the HIV-negative subjects there were no differences in cognitive function between subjects with and without a history of alcohol abuse. Among the HIV-positive subjects, those with a history of alcohol abuse performed more poorly on tests of verbal IQ, verbal reasoning, and reaction time.
Conclusions: There are both additive and interactive effects of previous alcohol abuse and HIV infection on cognition. Individuals with a history of past alcohol abuse may be at greater risk for cognitive dysfunction in the context of HIV infection.