Longitudinal Efficacy of Antidepressant Pharmacotherapy in Multiple Sclerosis

Background: Depressive disorders are highly prevalent comorbidities of multiple sclerosis (MS), and research has suggested that depression among MS patients remains stable over time. Despite the known risks of polypharmacy, little research has investigated the long-term benefits of antidepressant medication on the course of depression in MS.

Objectives: To evaluate the longitudinal efficacy of antidepressant medication in MS patients.

Methods: Participants (N = 349) were recruited from an outpatient MS clinic at a medical center in New Jersey. Longitudinal depression and medication data were collected as part of ongoing neuropsychological research. Medication information was obtained from participants through interview and medical records, while participants also completed the Beck Depression Inventory-II (BDI). Pearson Chi-Square test and linear regressions were used to examine the course of depression over time for participants in antidepressant-medicated and non-medicated groups.

Results: Outcome data ranged longitudinally from 0.92 to 71.33 months (M = 29.50, SD = 17.44). Antidepressant medication status did not significantly relate to clinically meaningful change in BDI score (Χ² = 2.619, p = .270). Time did not significantly predict change in BDI score for the antidepressant (β = −.050, p = .535) or non-antidepressant groups (β = −.006, p = .933).

Conclusions: Depression's stability in the MS population appears refractory to the effects of standard antidepressant pharmacotherapy longitudinally. Additional or alternate management of depressive disorders is indicated for patients with MS.