Neuropsychiatric aspects of HIV infection among older adults

Abstract

Treatment advances such as the advent of highly active antiretroviral therapy (HAART) have translated into greater life expectancy for HIV-infected individuals, which will ultimately result in a "graying" of the HIV/AIDS epidemic. In addition, older individuals are engaging in a higher rate of high risk behaviors than had been previously expected. As such, study of older HIV-infected patients, including study of the psychiatric and neurocognitive aspects of the disease, appears highly indicated. Epidemiological studies have demonstrated that HIV infection is associated with higher rates of several psychological/psychiatric disorders when compared to general population base rates. There is also a rich literature that has documented the adverse neurocognitive effects of HIV infection, ranging from subtle cognitive complaints to frank dementia, among younger adults. Although it has been hypothesized that older age may potentiate the deleterious effects of HIV infection, little is actually known, however, regarding the incidence, prevalence, course, and clinical features of HIV-associated psychiatric and cognitive dysfunction among older adults. This article provides an overview of the epidemiology and clinical manifestations of HIV-associated cognitive and psychiatric disorder across the age spectrum, with particular focus on what is known regarding the interaction of advancing age and HIV infection. Future directions for research are suggested, including basic epidemiologic study of incidence and prevalence rates of neurodisease among older HIV-infected adults as well as investigations designed to determine whether the nature, severity, course, or treatment of such disorders differs among older versus younger patients.

Fig. 1

Cognitive impairment: age by HIV disease status. HIV+/Non-AIDS = CDC. Groups A1, A2, B1, B2. AIDS = CDC Groups A3, B3, C1, C2, C3. Adapted from Hardy et al. (1999) [69]. Data drawn from a convenience sample of 694 HIV-infected and 282 uninfected controls, primarily sampled from infectious disease clinics specializing in the treatment of HIV infection.

Fig. 2

Percentage of persons reported to the CDC with a diagnosis of AIDS with an HIV encephalopathy as their initial AIDS-defining diagnosis (September 1987 to August 1991). From Janssen et al. (1992) [71]. These epidemiologic data are drawn from cases of HIV encephalopathy among 144,184 persons with AIDS reported to the Centers for Disease Control (CDC) from September 1, 1987 through August 31, 1991.

Fig. 3

Rates of psychopathology among older (≥50 years) and younger <50 years) HIV+ adults. Adapted from Hinkin and Castellon, 2000 [72]. These data are drawn from a convenience sample of 125 HIV-1 seropositive persons participating in a study of factors influencing medication adherence in HIV/AIDS. Approximately 25% of this sample were female, approximately 25% were over the age of 50, and roughly 80% were members of ethnic minority groups.