Psychomotor retardation and vulnerability to interferon alpha induced major depressive disorder: Prospective study of a chronic hepatitis C cohort.

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.