Emotional state of patients with relapsing-remitting MS treated with interferon beta-1b.

BACKGROUND: Depression has been cited as a possible side effect of interferon beta-1b (IFNbeta-1b) therapy in patients with MS. This association remains unproven because of a lack of longitudinal studies. OBJECTIVE: To determine the changes in emotional state in relapsing-remitting (RR) MS patients during the first 2 years of treatment with IFNbeta-1b. METHODS: Emotional state was evaluated in a sample of 90 patients at the onset of IFNbeta-1b treatment during an inclusion period of 2.5 years. Seventy-five patients were evaluated at their 12th month of treatment and 56 patients at their 24th month. We assessed their emotional state with the following psychological tests: Hamilton Depression Rating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. RESULTS: We found significant improvement in emotional state after the first and second years of treatment. CONCLUSIONS: Our findings show that IFNbeta-1b does not increase depression or anxiety in RR MS patients during the first and second years of IFNbeta-1b treatment. In fact, slight but significant improvement in depression and anxiety symptoms was observed during this period.