Disability Predicts Longitudinal Depression in People with Multiple Sclerosis

Background: Depression has been shown to be more stable over time in individuals with multiple sclerosis (MS) than in the general population. However, it is unclear what factors account for the stability of depression in people with MS. Prior research has found Expanded Disability Status Scale (EDSS) scores and measures of fatigue to be significant predictors of depression, but patients’ subjective perceptions of their disability have not been examined in this context.

Objectives: To evaluate the predictive value of disability data on depression over time.

Methods: Participants (N = 121) were recruited from an outpatient clinic at a large medical center in New Jersey. Longitudinal data were collected as part of an ongoing research project. Participants completed a Beck Depression Inventory-II (BDI-II), Incapacity Status Scale (ISS), and a demographic questionnaire. Linear regressions were used to assess the ISS as a predictor of BDI-II score at baseline and follow-up, and of change in BDI-II over time.

Results: ISS scores positively predicted BDI scores at baseline (β = .429, p < .001) and follow-up (β = .380, p < .001), and change in BDI-II score over time (β = .272 , p = .003).

Conclusions: Higher levels of disability predict greater depression in individuals with MS, both cross-sectionally and longitudinally.