Is hepatitis C infection associated with increased risk of depression in persons with methamphetamine dependence?

The abuse of methamphetamine (MA) has increased in the United States over the past 15 years and is associated with considerable negative social, psychological, and health effects, including symptoms of depression. Infection with the hepatitis C virus (HCV), which is independently associated with increased risk of depression, is common among MA users, possibly due to high rates of transmission risk behaviors in this cohort (eg, injection drug use). Given the prevalence of depression among HCV-infected individuals and MA users separately, the current study aimed to determine whether HCV infection and MA dependence are associated with additive effects on depression. Focused psychiatric evaluations were conducted on 39 individuals with both MA dependence and HCV infection (MA + HCV +), 57 persons with only MA dependence (MA + HCV -), and a comparison sample of 46 participants with neither risk factor (MA - HCV -). Consistent with prior research, greater self-reported symptoms of depression were observed in the MA + groups relative to MA - HCV - participants; however, there was no evidence to suggest an additive effect of HCV infection. Surprisingly, the prevalence of current and lifetime diagnoses of Major Depressive Disorder (MDD) did not differ across the study groups. Results from this study suggest that HCV infection does not confer an additive effect on the severity of depressive symptoms or the prevalence of major depression in persons with MA dependence.