Interferon β1a and depression in secondary progressive MS: Data from the SPECTRIMS Trial

Depression is a suspected side effect of treatment with interferon beta1a in MS. However, an association with depression has not been confirmed by rigorous studies. During the SPECTRIMS clinical trial of interferon beta1a (Rebif) in secondary progressive MS, depression ratings were obtained from 365 subjects treated either with interferon beta1a or with placebo. No significant differences between groups emerged during 36 months of follow-up. These data suggest that depression is not a side effect of interferon beta1a.