Relationship between depressive symptoms and adherence to direct-acting antivirals: Implications for Hepatitis C treatment among people who inject drugs on medications for opioid use disorder

Background: Interferon-based regimens exacerbated depressive symptoms, which interfered with treating hepatitis C virus (HCV) among people who inject drugs (PWID). Direct-acting antivirals (DAA) are not associated with worsening depressive symptoms; however, the impact of depressive symptoms on adherence remains little known. We examined the association between depressive symptoms and adherence to DAA among HCV-infected PWID. A secondary aim was to identify the optimal cut-off for major depressive disorder for this population. Methods: Participants were 150 HCV-infected PWID on maintenance treatment enrolled in a randomized clinical trial testing three HCV care models. Severity of depressive symptoms were assessed using the Beck Depression Inventory-II (BDI-II) at baseline and every 4 weeks during treatment. Current major depressive disorder at baseline was diagnosed by the Mini-International Neuropsychiatric Interview. Adherence was measured during treatment (weeks 1-12) using electronic blister packs Results: BDI-II scores > 18 were identified as the optimal threshold for diagnosing major depressive disorder. Participants with BDI scores > 18 at baseline had significantly lower adherence rates at weeks 1-4 of treatment compared to those with BDI scores < 18 (b = -0.23, 95% CI: 0.45-0.01, p = 0.044), but not in any other time intervals (weeks 5-8, b = -0.03, 95% CI: -0.32, 0.26, p = 0.825; weeks 9-12, b = -0.33, 95% CI -0.70, 0.02, p = 0.066). Conclusions: Elevated depressive symptoms were associated with lower adherence to DAA only during the first 4 weeks of HCV treatment. Neither severe depressive symptoms nor major depressive disorder appears to be a barrier to DAA adherence among PWID.