Aim: Pegylated interferon (PegIFN) therapies for hepatitis C virus (HCV) infection often induce a depressive state. This study aimed to identify the risk factors for and clinical characteristics of PegIFN-induced depressive state.
Methods: Sixty-nine subjects with HCV who received PegIFN therapy were enrolled. Before beginning therapy, all subjects were evaluated using the Neuroticism-Extraversion-Openness Five-Factor Inventory and the List of Threatening Events Questionnaire. Beck Depression Inventory (BDI) scores were also evaluated at baseline, 2-4 weeks after initiating therapy, and every 4 weeks thereafter.
Results: During the study, 18 subjects (24.3%) developed a depressive state (BDI >= 10). A bimodal peak of onset was observed during the early (28 weeks) and late (after 20 weeks) therapy phases. Moreover, we observed that baseline BDI scores (odds ratio [OR] = 1.40, P = 0.0104) and neuroticism (OR = 1.14, P = 0.0275) were significant risk factors for developing a depressive state. To determine the specific characteristics of this condition, we compared the BDI subscales between the 'PegIFN-induced' and 'general' depressive state reported previously. We found that the score at 'somatic symptoms' was higher in the 'PegIFN-induced' group.
Conclusion: Our results indicate the following: (i) PegIFN-induced depressive state most frequently develops during the first 8 weeks of therapy; (ii) baseline BDI and neuroticism scores are risk factors for PegIFN-induced depressive state; and (iii) the core symptoms of PegIFN-induced depressive state are different from those of 'general' depression.