Outcomes of the effect of exercise on cognitive function in patients with depression: A meta-analysis.

Background: Major depressive disorder is a common mental disorder, characterized by a high rate of suicide and recurrence, which is frequently accompanied by cognitive impairments, particularly in executive function, memory, attention, and information processing speed. As such, improving the cognitive function in patients with depression and enhancing their quality of life are urgent issues.

Aim: To perform a systematic review and meta-analysis of the effects of exercise on cognitive function in patients with depression.

Methods: The PubMed, Web of Science, Cochrane Library, Embase, China National Knowledge Infrastructure, Wanfang Medical, VIP, and Biomedical Databases for randomized controlled trials (RCTs) databases were searched (from inception to October 19, 2023) for studies investigating improvements in cognitive function in patients with depression through exercise. Tools recommended by the Cochrane Handbook for RCT evaluation, and GRADEpro and Stata17 software, were employed for risk of bias assessment, evidence grading, forest plot construction, subgroup and sensitivity analyses, and assessment of publication bias.

Results: Seventeen RCTs (1173 patients with depression) were included. Exercise had a small but significant positive effect on attention, with an effect size of 0.21, 95%CI: 0.07-0.34, P < 0.01. Specifically, aerobic exercise regimens of 30-60 minute/session, thrice a week, at moderate intensity, and sustained over 3-12 weeks, were associated with the most pronounced benefits (P < 0.05), with effect sizes for executive function, memory, and information processing speed of 0.11, 95%CI: -0.11-0.32, P = 0.34; 0.08, 95%CI: 0.00-0.16, P = 0.05; and 0.14, 95%CI: 0.04-0.25, P = 0.01, respectively. The evidence levels for attention, information processing speed, and memory were rated as 'low,' whereas that for executive function was rated as 'very low'.

Conclusion: Exercise could improve attention and information-processing speed in patients with depression, although improvements in executive function and memory are not significant.