Early neuropsychological impairment in HIV‐seropositive intravenous drug users: evidence from the Italian Multicentre Neuropsychological HIV Study

Abstract

The aim of the Italian Multicentre Neuropsychological HIV Study is to assess the prevalence and natural history of cognitive deficit in intravenous drug users (i.v.DUs) during the asymptomatic phase of HIV infection. The study is currently being conducted in four centres (Napoli, Benevento, Verona and Pavia) whose catchment areas are characterized by different levels of prevalence of HIV infection. Cognitive evaluation is being performed by means of a standardized neuropsychological test battery. A total of 251 subjects (167 males and 84 females) have been recruited in the cross-sectional phase of the study, including 75 asymptomatic HIV-seropositive i.v.DUs (HIV+/i.v.DUs), 97 HIV-seronegative i.v.DUs (HIV-/i.v.DUs) and 79 non-i.v.DU seronegative controls matched to i.v.DUs with regard to sex, age and educational level. The prevalence of global cognitive impairment (performance at least 1.5 standard deviations worse than the average of the control group, on at least two out of five tests) was significantly higher in HIV+/i.v.DUs than in either HIV-/i.v.DUs (22.7% vs. 8.2%; P < 0.01) or healthy controls (22.7% vs. 2.5%; P < 0.001). The difference between HIV-/i.v.DUs and healthy controls was not statistically significant (8.2% vs. 2.5%; P = 0.19). The results of this study lend further support to the 'cerebral reserve' model. The cerebral reserve could indeed be reduced in i.v.DUs as a consequence of chronic exposure to the substance of abuse, so that these subjects become more vulnerable to direct and indirect neurotoxic effects of HIV.

Sensation Seeking and Visual Selective Attention in Adults with HIV/AIDS

“…Individual differences in sensation seeking and/or arousal might also explain the inconsistency in research results on drug abuse and HIV infection. Although some studies report greater cognitive impairment in drug abusing HIV positive adults relative to control subject groups (seronegative drug abusers and clean seronegatives) (e.g., Starace et al 1998), other studies report no interactive effect between drug abuse and HIV infection (e.g., Selnes et al 1997). Perhaps the greater sensation seeking (on average) in HIV positive drug abusers facilitates their selective attention and related cognitive abilities, offsetting any expected exacerbated cognitive deficits due to drug abuse.…”

Neuropsychological Complications of HIV Disease and Substances of Abuse

“…In one study, 251 individuals were categorized into three groups: 75 asymptomatic HIV-seropositive IDUs, 97 HIV-seronegative IDUs and 79 HIV-seronegative non-IDUs. Five cognitive tests were administered and the results combined to calculate global cognitive impairment (GCI) [75] . The outcomes indicated that the prevalence of GCI was significantly higher in HIV seropositive IDUs, than in either of the two groups of HIV-seronegative individuals.…”

The Impact of Neuropsychological Functioning on Adherence to HAART in HIV-Infected Substance Abuse Patients

“…This rate of impairment is considerably higher than found in prior studies with similar samples. 16,72 Additionally, neuropsychological impairment was not associated with adherence and was not associated with a discrepancy between self-reported and a more objective (MEMS) measure of adherence. However, the WTARused here as a proxy for premorbid verbal intelligence-was a significant predictor of the discrepancy between electronically monitored and self-reported adherence.…”

“…[4][5][6][7][8] However, less severe deficits in memory, concentration and attention abilities remain common, [9][10][11] with some estimates as high as almost 40%. 6 Substance use, also common in this population, is a major risk factor thought to exacerbate neuropsychological dysfunction, 12 and the risk of neuropsychological impairment may be particularly high in opiate users 13,14 and methadone maintenance patients, [15][16][17][18][19] regardless of HIV status. However, at least one study 20 suggests that engagement in methadone maintenance therapy improves neuropsychological performance.…”