Early Treatment Improvements in Depression Are Associated With Overall Improvements in Fatigue Impact and Pain Interference in Adults With Multiple Sclerosis

Background Depression, fatigue, and pain commonly co-occur in multiple sclerosis (MS) and are positively associated with one another. However, it is unclear whether treatment-related improvement in one of these symptoms is associated with improvements in the other two symptoms. Purpose This study examined whether early improvements in depressive symptoms, fatigue impact, and pain interference during a multisymptom intervention in persons with MS were associated with overall improvements in the other two symptoms. Methods Secondary analysis of a randomized controlled trial in which both treatments improved depressive symptoms, fatigue, and pain interference. Adults with MS experiencing chronic pain, chronic fatigue, and/or moderate depressive symptoms (N = 154, 86% women) participated in an 8-week, telephone-delivered intervention: self-management (n = 69) or education (n = 85); intervention groups were combined for the current study. Outcome measures were depressive symptoms (PHQ-9), fatigue impact (Modified Fatigue Impact Scale), and pain interference (Brief Pain Inventory). Path analysis examined associations between pre-to-mid intervention improvement in one symptom (i.e., depression, fatigue, pain interference) and pre-to-post (overall) improvement in the other two symptoms. Results Early reduction in depressive symptoms was associated with an overall reduction in pain interference and fatigue impact (p's < .01). Early reduction in fatigue impact was associated with an overall reduction in depressive symptom severity (p = .04) but not pain interference. Early reduction in pain interference was not associated with reductions in fatigue impact or depressive symptoms. Conclusions These findings suggest the potential importance of reducing depressive symptoms to overall improvement in fatigue and pain interference in persons with MS.