Drug Abuse and Hepatitis C Infection as Comorbid Features of HIV Associated Neurocognitive Disorder: Neurocognitive and Neuroimaging Features

Abstract

Substance abuse and co-infection with hepatitis C (HCV) are two highly relevant determinants of neurocognitive and neuroimaging abnormalities associated with HIV. Substance abuse and HCV are common in the HIV population and there is increasing evidence that the CNS is directly compromised by these comorbid conditions via additive or synergistic processes. In this article we review the current literature regarding mechanisms of neuronal injury as well as the neuropsychological and neuroimaging signatures associated with substance abuse and HCV status among HIV patients. We discuss specific methodological challenges and threats to validity associated with studies of HIV and comorbid substance use disorders or HCV and review potential strategies for minimizing their confounding effects. Efforts to understand the interactions between HIV, substance abuse and HCV co-infection will lead to more complete models of neuropathogenesis of HIV and a greater understanding of the variability in neuropsychological expression of HIV Associated Neurocognitive Disorder.

The neuropsychiatric aspect of the HCV infection

“…The prognosis for HIV dis-ease becomes significantly worse among the HCV infected subjects. 6 Both viruses have effects that may contribute to CNS dysfunction. 6,7 Patients in the asymptomatic HIV stage often exhibit impaired attention, speed of processing and working memory.…”

“…2 On the other hand, Clifford et al showed in their study that patients simultaneously infected with HIV and HCV achieved worse results in cognitive tests and were more depressed (57 vs. 32% among HIV infected). 6 Also Chermer et al report that the HCV infection independently influences the impairment of cognitive functioning, especially learning abilities, abstract thinking and motor skills. 6 Changes in the white matter were reported in the co-infected subjects, suggesting a direct relation with the presence of HCV in the brain.…”

“…In accordance with literature data, the frequency of psychiatric disorders concomitant with HCV has increased dramatically. 4,6 What is more, the HCV infection is significantly more prevalent in the population of psychiatric patients than in the general population. The prevalence is estimated to be 9-11 times higher, and reaches nearly 20%, without discrepancies between groups, among psychiatric in-and out-patients.…”

“…It is being considered that acquiring one of the viruses is a risk factor of being infected with the other. 6 The unspecific character of the psychopathological symptoms in the HCV infection makes the process of thorough diagnostics and adequate treatment difficult. 5 The clinical picture is quite often unclear, with somatic symptoms attracting all the attention; the psychiatric symptoms are non-specific and often recognized as manifestations of the viral infection.…”

“…3,5 Untreated psychiatric disorders not only decrease the already low quality of life but also cause non-adherence, contributing to worse treatment outcomes. 6 Finally, the above disorders, when left untreated, result in higher rates of risk-taking behaviors among the infected, thus imposing a danger not only to patients themselves but also to the healthy population. 3 This article presents a spectrum of psychopathological symptoms and psychological dysfunctions, an outline of current theories on the neuropathology and psychiatric aspects of HCV infection treatment.…”