Background: Major depressive disorder (MDD) is a common consequence of interferon alpha (IFNα) treatment and important supporting evidence of a role of inflammation in the aetiology of depression.
Objective: This study aimed to expand the knowledge of baseline clinical vulnerability characteristics to IFNα induced MDD, particularly exploring sub-threshold depressive symptoms.
Methods: A prospective cohort of chronic HCV patients undergoing treatment with pegylated-IFNα and ribavirin was studied. MDD was assessed using the Structured Clinical Interview for DSM-IV (SCID-I). Depressive symptoms and severity were assessed at baseline and monthly with the Hamilton Depression Rating Scale (HAMD). Subjects with MDD or taking antidepressant treatment at baseline were excluded.
Results: 278 patients were assessed for this cohort with a final study sample of 190. 94.2% had contracted HCV through intravenous drug use. During six months IFNα treatment, 53.2% of patients transitioned to DSM-IV threshold MDD. In the multivariate logistic analysis, independent factors significantly associated with development of MDD were younger age (OR 0.96, 95% CI 0.93-1.00, p=0.028), past history of MDD (OR 3.82, 95% CI 1.63-8.92, p=0.002), baseline HAMD items psychomotor retardation (OR 15.21, 95% CI 1.33-173.41, p=0.032) and somatic symptoms (general) (OR 2.96, 95% CI 1.44-6.08, p=0.003), and HCV genotype 2 (OR 2.27, 95% CI 1.07-4.78, p=0.032).
Conclusions: During IFNα treatment, the rate of transition to MDD was high in this cohort. Psychomotor retardation and somatic symptoms may represent a greater inflamed state pre-treatment. This iatrogenic model of MDD may offer important insights into wider depression aetiology.
Keywords: Depressive disorder; Hepatitis C; Inflammation; Interferon-alpha; Prospective studies.
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