Multiple sclerosis and depression: influence of interferon b therapy

Abstract

Background and objectives: Depression is frequently part of the clinical picture of multiple sclerosis (MS). Major depression affects one in two patients with MS during the course of their lifetime. O ur objectives were to determine first, whether interferon b-1a (IFNb-1a) treatment increases the risk or level of depression and, secondly, whether depression status and depression evolution are related to the clinical characteristics of the disease. Patients and methods: We investigated 106 consecutive patients with relapsing-remitting MS treated with IFNb-1a (Avonex®). Patients with evidence of severe depression were excluded. The depression status, scored on the Beck Depression Inventory (BDI-II) (stratified as minimum, mild, moderate or severe level), and disability, scored on the Expanded Disability Status Scale (EDSS), were evaluated before and after 12 months of IFNb-1a treatment. Results: At baseline, 85% of patients had a minimum or a mild depression status and after 12 months of treatment most of them (83%) retained their baseline status. Beck scores before and after treatment were not significantly different (P =0.63). There was no correlation between age, gender, duration of illness or EDSS score and Beck score at baseline (P =0.696). Patients with disability progression after one year of IFNb-1a treatment had a significantly higher Beck score at baseline than patients without disability progression (P =0.003). Conclusion: IFNb-1a (Avonex®) does not seem to significantly influence the depression status of MS patients even in those with disability progression.