The relationship between depression and cognitive performance in multiple sclerosis: A meta-analysis

Abstract

Objective: Studies on the relationship between depression and cognition on patients with multiple sclerosis (MS) are inconsistent and it is not clear whether higher depression levels are associated with impairment of specific cognitive domains or processes. This meta-analytic study aimed at evaluating the possible association between depressive symptomatology and performance on cognitive tests assessing several cognitive domains (global cognition, attention, processing speed, verbal, spatial and working memory, verbal fluency, inhibitory control, set-shifting) in individuals living with MS. Method: The literature search on three electronic databases yielded 5402 studies (4333 after the duplicates removal); after the evaluation of titles, abstracts full-text articles, 37 studies were included in the meta-analytic study. A random-effect model meta-analysis was performed and mean weighted effect sizes (ESs) were calculated using Hedges’ g. Results: Small ESs were found for the relationship between depression and verbal memory (g = 0.25, p < 0.001), spatial memory (g = 0.23, p < 0.001), verbal fluency (g = 0.26, p < 0.001), and inhibitory control (g = 0.32, p = 0.003). Medium ESs were found for the relationship between depression and global cognition (g = 0.46, p < 0.001), attention (g = 0.43, p < 0.001), processing speed (g = 0.47, p < 0.001) and working memory (g = 0.38, p = 0.037). The relationship between set-shifting abilities and depression was not significant (g = 0.39, p = 0.095). Conclusions: Results suggest that patients with MS and higher levels of depressive symptomatology may also show more difficulties in several aspects of cognition, especially those needed to retain, respond, and process information in one’s environment, and to those needed be adequately stimulated in processing relevant information.

Keywords:

• Multiple sclerosis
• depression
• cognition
• cognitive performance
• meta-analysis

Acknowledgments

The authors thank Dr. Margaret Cadden, Prof. Fabienne Colette, Dr. Doug Denney, Dr. Camille Guillemin, Dr. Lars Næsby Hvid, Dr. Hanne Van Ballegooiijen, and Prof. Leo Visser for support and for providing additional data from their published articles.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that support the findings of this study are available from the corresponding author, G.S., upon reasonable request.