Multiple sclerosis: A prospective evaluation of depression

Abstract

Objectives. Approximately 50% of Multiple Sclerosis (MS) patients have depression as a comorbid psychological disorder. The aim of this prospective study was to assess various factors to determine which were predictors of depression. Methods. Using hierarchical linear regression and other analyses, demographic and disability severity data, Incapacity Status Scale (ISS), were evaluated as predictors of the Beck Depression Inventory-II (BDI). Results. Depression scores increased from Time 1 to Time 2. A significant Pearson correlation coefficient was found for depression and disability scores. Disability was found to be a predictor of BDI scores at Time 1:t (118) = 6.06, p < .05, and Time 2:t (87) = 3.24, p < .05. Age was found to have a negative correlation with depression. Age, which exhibited a trend initially, became a significant predictor of BDI scores by Time 2:t (87) = -2.58, p < .05.;Principal component analysis demonstrated that BDI items loaded strongly into three components. The components were used to form subscales, which were able to describe different facets of the BDI construct. One subscale, General Depression (GD), demonstrated a strong correlation with BDI total scores. GD was shown to be a purer measure of depression for MS patients and was utilized as an outcome variable. The remaining subscales, Anhedonia/Fatigue (AF) and Neurocognitive (NC), included items that reflected MS symptoms.;The disease severity increased slightly from Time 1 to Time 2. BDI, GD, and ISS scores were shown to be nearly invariant from Time 1 to Time 2. Conclusion. Age and disability severity were shown to be predictors of depression. PCA of BDI yielded three components, one of which was less confounded with MS symptoms in this sample population.