A-171 Dissociable Dimensions of Multiple Sclerosis-Related Depression

Abstract Objective: Multiple sclerosis (MS) is associated with increased risk of depression and suicide. Preliminary literature suggests that sadness and anhedonic aspects of depression may dissociate in MS. Based on this, we hypothesized that there would be three subtypes of depression experienced by individuals with MS: primarily sad, primarily anhedonic, and mixed (i.e., elevated anhedonia and sadness), and that certain dimensions would be associated with higher degrees of suicidal ideation. Method: Participants included 117 patients with MS [Mean (Standard Deviation): age = 47.48 (10.21) years; 78.9% female; 97.3% White non-Hispanic; disease duration = 7.86 (8.30) years; Expanded Disability Status Scale: Median = 3, Range = 0 to 8.0]. Depression was measured using the Beck Depression Inventory-II (BDI-II). Patients’ level of mood symptoms ranged from non-depressed to severely depressed [10.26 (9.35)]. Results: Principle components analysis of BDI-II item-level responses indicated that symptoms in patients with MS dissociated into three dimensions accounting for 59% of variance in total. Dimension 1 included eight items related to negative cognitions, including pessimism, loss of hope and suicidal thoughts. Dimension 2 consisted of eight items characterized by vegetative symptoms and anhedonia. Dimension 3 was comprised of five items pertaining to sadness and emotion regulation issues. Conclusion(s): There appear to be three dimensions of depression experienced by adults with MS, and the negative cognitions dimension is most strongly related to suicidality, highlighting the importance of screening for this aspect of depression in individuals with MS.