Mult Scler. 2021 Jul;27(8):1284-1292. doi: 10.1177/1352458520961534. Epub 2020 Sep 25.

Ruth Ann Marrie ¹, Ronak Patel ², Charles N Bernstein ³, James M Bolton ⁴, Lesley A Graff ², James J Marriott ³, Carol A Hitchon ³, Chase R Figley ⁵, Jennifer Kornelsen ⁵, John D Fisk ⁶

Author information

• ¹Department of Internal Medicine, Rady Faculty of Health Sciences, Max Rady College of Medicine, Health Sciences Center, University of Manitoba, Winnipeg, MB, Canada/Department of Community Health Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.
• ²Department of Clinical Health Psychology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.
• ³Department of Internal Medicine, Rady Faculty of Health Sciences, Max Rady College of Medicine, Health Sciences Center, University of Manitoba, Winnipeg, MB, Canada.
• ⁴Department of Psychiatry, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.
• ⁵Department of Radiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada/Division of Diagnostic Imaging, Health Sciences Centre, Winnipeg, MB, Canada/Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, MB, Canada.
• ⁶Departments of Psychiatry, Psychology & Neuroscience, and Medicine, Dalhousie University, Halifax, NS, Canada.

Abstract

Background: Longitudinal studies assessing depression and anxiety effects on cognition in multiple sclerosis (MS) are limited.

Objective: We tested whether within-person fluctuations in symptoms of depression or anxiety over time affect cognition in persons with MS, inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and a lifetime history of depression/anxiety disorders (DEP/ANX) but without an immune-mediated inflammatory diseases (IMID).

Methods: We followed participants (MS: 255, IBD: 247, RA: 154, and DEP/ANX: 306) for 3 years. Annually, they completed the hospital anxiety and depression scale (HADS) and cognitive tests including the symbol digit modalities test (SDMT). We evaluated associations of elevated symptoms (scores ? 11) of anxiety (HADS-A) and depression (HADS-D) with SDMT z-scores using multivariable linear models-estimating between-person and within-person effects.

Results: Participants with MS performed worse on the SDMT than participants in the DEP/ANX cohort (β = -0.68; 95% CI: -0.88, -0.48). Participants with elevated HADS-A scores performed worse on the SDMT than those without elevated scores (β = -0.43; 95% CI: -0.65, -0.21), particularly those with RA. Time-varying within-person elevations in depressive symptoms were associated with worse SDMT performance (β = -0.12; 95% CI: -0.21, -0.021).

Conclusions: Across persons, elevated symptoms of anxiety adversely affected information processing. Elevated symptoms of depression within-persons over time were associated with declines in information processing speed.