Treatment with pegylated interferon alpha (PEG-IFN-α) is associated with depression more frequently in chronic hepatitis C (CHC) patients than with other inflammatory diseases.

To prospectively asses sex differences in the prevalence of depression in CHC patients during the PEG-IFN-α, as well as in the CHC group with no therapy.

Sample consisted of 103 subjects with CHC on the PEG-IFN-α and 103 subjects with CHC without interferon therapy. The diagnosis of depressive disorder was established by using Structured Clinical Interview and Criteria of International Classification Disorder. The severity of depression was assessed by using Hamilton Depression Rating Scale (HAMD ≥ 8) prior to PEG-IFN-α (baseline) and at the follow-up visits (4th, 12th, 24th, 48th, 72nd week).

During the course of PEG-IFN-α, 49.5% of subjects showed depressive symptomatology (HAMD ≥ 8). Except at baseline and in the 72nd week, on the all other follow-up visits the prevalence of depression was significantly higher in female subjects (*all Ps < 0.05). The strongest difference was observed in the 12th week: of all the subjects with HAMD ≥ 8, 68.8% were female and 32.7% were male (P < 0.001). The multivariate logistic regression model showed that female sex is a very strong predictor for the development of depression during the interferon treatment [Exp (B) = 6.729]. There were no significant sex differences in the prevalence of depression in the control group.

Our study (the longest study in this area) indicate that the prevalence of depression is significantly higher in female subjects with CHC during antiviral treatment.

The authors have not supplied their declaration of competing interest.