Neuropsychiatric manifestations of hepatitis C treatment in HIV/HCV co-infection

Hepatitis C (HCV) infection is associated with high rates of mortality and morbidity. Interferon alpha based treatment for HCV offers a good rate of viral clearance, however the associated neuropsychiatric side effects increase the risk of treatment interruption and disease progression. The HIV/HCV coinfection is of particular interest due to association with higher rates of HCV treatment side effects and earlier treatment discontinuation when compared with HCV mono-infection. Therefore, the aim of the thesis was to further explore the effect of coinfection on mood and cognition and how HCV interferon based treatment influences neuropsychiatric side effects in mono and co-infected samples. Firstly a meta-analysis was performed to explore cognitive impairment and depression in HIV HCV co-infection. The results suggested that there was consistent literature indicating that the coinfected group were more cognitively impaired and more likely to be depressed than the HCV and HIV monoinfected groups. Secondly empirical studies were conducted to analyse the profile of depression during interferon-based treatment, and explore potential risk factors, such as gender and immune profile. Co-infected patients appeared less vulnerable to the emergence of depressive symptoms during HCV treatment than HCV mono-infected patients. Additionally, neither female gender nor immune response were associated with increased vulnerability to depression. Finally, a longitudinal study investigating cognitive performance during interferon-based treatment was conducted. A significant effect of treatment on information processing speed level of executive function was observed. Overall the research reported in this thesis further clarifies the nature of interferon induced depression and cognitive effects differences between mono and coinfected groups. Having identified a neurovegetative symptom profile and speed of processing impairment of executive function during HCV treatment, the discussion considers the potential of targeted interventions via psychotropic medication and cognitive interventions to minimise the impact of these treatment effects and optimise outcomes in this clinical group