Depression and cognitive function in early multiple sclerosis: Multitasking is more sensitive than traditional assessments
Lisa Glukhovsky, Daniel Kurz, Rachel Brandstadter, Victoria M. Leavitt, Stephen Krieger, Michelle Fabian, Ilana Katz Sand, Sylvia Klineova, Claire Riley, Fred Lublin, Aaron Miller, James Sumowski
Abstract
Background: Persons with multiple sclerosis (MS) and depression symptoms report real-world cognitive difficulties that may be missed by laboratory cognitive tests. Objective: To examine the relationship of depressive symptoms to cognitive monotasking versus multitasking in early MS. Method: Persons with early MS ( n = 185; ⩽5 years diagnosed) reported mood, completed monotasking and multitasking cognitive tests, and received high-resolution 3.0 T magnetic resonance imaging (MRI). Partial correlations analyzed associations between mood and cognition, controlling for age, sex, estimated premorbid IQ, T2 lesion volume, and normalized gray matter volume. Results: Depression symptoms were more related to worse cognitive multitasking (−0.353, p < 0.001) than monotasking ( r = −0.189, p = 0.011). There was a significant albeit weaker link to cognitive efficiency composite score ( r = −0.281, p < 0.001), but not composite memory ( r = −0.036, p > 0.50). Findings were replicated with a second depression measure. Multitasking was worse in patients with at least mild depression than both patients with no/minimal depression and healthy controls. Multitasking was not related to mood in healthy controls. Conclusions: Depression symptoms are linked to cognitive multitasking in early MS; standard monotasking cognitive assessments appear less sensitive to depression-related cognition. Further investigation should determine directionality and mechanisms of this relationship, with the goal of enhancing treatment for cognitive dysfunction and depression in MS.