Twenty-five HIV-seropositive drug abusers (DA + HIV + ) (groups II-III
and IV [A, C2 and E] of the CDC classification) were evaluated by use
of the WAIS scale to determine any possible involvement of cognitive
functions in the not yet overt phases of AIDS. The results were compar
ed with those obtained in two control populations composed of 19 seron
egative drug abusers (DA + HIV - ) and 24 healthy subjects (DA - HIV -
) to evaluate, in addition to the disease, the possible effect of the
use of alcohol and toxic substances on cognitive performance. In spit
e of the small number of subjects, the study indicated that drug abuse
is the main factor, among those analyzed, in determining a decline in
cognitive functions.