• Neurobehavioral deficits as observed on neuropsychological testing in HIV/HCV-coinfected individuals before and after receiving anti-HCV treatment. [ Time Frame: Measured before drug administration, Week 12 of drug administration, and Week 12 of follow-up ] [ Designated as safety issue: No ]
  

• Psychiatric symptoms [ Time Frame: Measured before drug administration, Week 12 of drug administration, and Week 12 of follow-up ] [ Designated as safety issue: No ]
  
• Neuroimaging data (from a nested cohort of participants) [ Time Frame: Measured before drug administration, Week 12 of drug administration, and Week 12 of follow-up ] [ Designated as safety issue: No ]
  

The World Health Organization estimates at least 3% of the world's population is infected with chronic hepatitis C virus (HCV), and up to one third of all HIV infected people are coinfected with HCV. HCV can damage the liver cells and cause liver diseases such as cirrhosis and hepatocellular carcinoma. People infected with HCV can also suffer from neurocognitive deficits, including problems with information processing, slowing of muscular processes related to thinking, and difficulty focusing on complex things. These neurocognitive deficits are similar to those found in HIV infected individuals, and previous research indicates that people infected with both HIV and HCV have greater overall cognitive impairments. This study aims to determine the impact of anti-HCV treatment on neurocognitive, neuropsychiatric, and neuroimaging factors in people infected with HCV and people coinfected with both HCV and HIV. The study also aims to measure whether possible neurocognitive improvements from anti-HCV treatment are related to a physical health outcome, measured as a sustained virologic response, and whether adherence to the medication schedule laid out for the participants influences possible positive effects on either neurocognitive or physical health.

Two kinds of participants will be recruited for this study: those infected with HCV and those infected with both HCV and HIV. These two groups will be compared to determine how comorbid HCV and HIV infection affects treatment outcomes. The treatment specified for HCV is pegylated interferon alfa and ribavirin (PEG-IFN/RBV), considered standard care for patients with chronic HCV. Participants will continue to see their doctors as regularly scheduled, and any other prescribed medications or advice concerning HCV treatment will be noted by researchers.

All participants will be tested at baseline, after 12 weeks of treatment, and 12 weeks after the completion of treatment. A subset from each group of participants will undergo additional neuroimaging tests. Participation in this study will last for varied amounts of time depending on the recommended treatments for HCV. Based on each virus' genotype and rapid virologic response, the treatment period for HCV may last 24 or 48 weeks, with further extensions of 12 to 24 weeks in some cases.

During the three testing sessions, each lasting 5 hours, participants' health, cognitive functioning, and medication adherence will be measured. Testing will include self-report measures, intelligence tests, tasks designed to assess cognitive functioning, and motor functioning tasks. Urine tests screening for narcotics will also be collected. In addition to self-report measures, caps to pill bottles storing HCV medication will automatically record every time the cap is removed to measure adherence to the medication schedule.