Relationship between disease-modifying therapy and depression in multiple sclerosis.

Many prescribers of disease-modifying therapies (DMTs) for multiple sclerosis (MS) believe that interferon beta (IFNβ) is more likely than glatiramer acetate (GA) to increase depression during the course of MS treatment. Therefore, newly diagnosed patients with a history of depression are often placed on GA therapy from the onset of MS treatment. The aim of this study was to examine the relationship between DMT type and depression among patients with relapsing-remitting MS (RRMS). Patients with RRMS who were examined from 2000 to 2007 and who remained on a single course of therapy (either an IFNβ or GA) were included in a retrospective review of medical records. Patients were asked to complete the Beck Depression Inventory (BDI) at treatment initiation and every 6 months thereafter for up to 4 years. Only patients who had completed a BDI within 6 weeks of starting their DMT were included in the analysis. No significant differences in mean change in BDI score were observed from baseline to 48 months between the IFNβ and GA subgroups. Additionally, no significant differences in mean BDI score change were observed between antidepressant-treated and non-antidepressant-treated patients within the IFNβ or GA subgroup. Neither IFNβ nor GA therapy appears to exacerbate depressive symptoms in patients with RRMS who remain on their initial therapy.