The progressive stages of cocaine abuse typically begin with euphoria, leading over time to dysphoria, paranoia, and cocaine psychosis. Cocaine psychosis often includes depression, delusional thinking, visual and auditory hallucinosis, and paranoia. After quitting cocaine, such symptoms usually remit within several days. Neuropsychiatric complications may also appear as manifestations of AIDS, AIDS-related complex, or direct central nervous system involvement of the human immunodeficiency virus (HIV). Early symptoms of such complications may predate seropositivity for HIV and may include many of the same symptoms as cocaine psychosis. Cocaine abuse may not only increase an individual's chances of becoming HIV positive and developing AIDS-spectrum disorders by virtue of its immuno-suppressive effects and the potential for repeated exposure to HIV through the sharing of contaminated needles, but the symptomatology of advanced cocaine psychosis may, in some cases, closely resemble and thereby mask the manifestations of the true cause of a patient's psychopathology, i.e., HIV. To minimize diagnostic errors, clinicians must adhere to a multidimensional assessment model. 20 references.