Treatment of depression improves adherence to interferon beta-1b therapy for multiple sclerosis

Objectives: To examine the relationship between patient-reported depression and adherence to therapy with interferon beta-1b (IFNβ-1b) and to test the hypothesis that treatment of depression is associated with improved adherence. Design: Patients with multiple sclerosis were followed up 6 months after initiating therapy with IFNβ-1b. Setting: A university outpatient multiple sclerosis center, an academic group practice, and a health maintenance organization. Patients: Eighty-five patients with clinically evident multiple sclerosis taking IFNβ-1b. Main Outcome Measure: Follow-up questionnaire. Results: Thirty-five (41%) of the 85 patients reported new or increased depression within 6 months of initiating therapy with IFNβ-1b. Patients experiencing symptoms of depression were more likely to discontinue therapy. Among the patients reporting new or increased depression, 86% who received psychotherapy or antidepressant medication and 38% of the patients who received no therapy for depression continued the IFNβ-1b therapy (P=.003). Although psychotherapy was used as a treatment option more frequently in university and academic group practice-based multiple sclerosis clinics than in the health maintenance organization (P=.02), the treatment adherence patterns were similar across sites. Conclusions: These findings support previous findings that patients report increased depression after initiating therapy with IFNβ-1b. Although the source of this depression is unclear, these findings suggest that treating patient-reported depression increases adherence to treatment.