Somatic symptoms and the association between hepatitis C infection and depression in HIV-infected patients.

Studies of depression and hepatitis C virus (HCV) infection in HIV-infected patients have been contradictory and often not addressed key differences between HCV-infected and uninfected individuals including substance use. This cross-sectional observational study from the University of Washington HIV cohort examined associations between HCV, symptoms, and depression in HIV-infected patients in routine clinical care. Patients completed instruments measuring depression, symptoms, and substance use. We generated depression severity scores and used linear regression to examine the relationship with HCV accounting for demographic and clinical characteristics. We conducted sensitivity analyses in which we removed depression somatic symptom items (e.g., fatigue) from depression scores, and sensitivity analyses in which we also adjusted for nondepression somatic symptom items to examine the role of somatic and nonsomatic symptoms in the association between depression and HCV. Of 764 HIV-infected patients, 160 (21%) were HCV-infected. In adjusted analysis, HCV-infected patients had worse depression severity (p =0.01) even after adjusting for differences in substance use. HCV remained associated with depression severity in secondary analyses that omitted the depression somatic patient health questionnaire-9 (PHQ-9) items (p=0.01). However, when nondepression somatic symptoms were included as covariates in multivariate analyses, HCV was no longer associated with depression (p=0.09).