A systematic review and meta-analysis published in BMC Psychiatry found that cognitive rehabilitation was effective at improving executive function, verbal learning, and working memory among patients with major depressive disorder (MDD).
Investigators from universities in Iran searched publication databases through March 2022 for randomized controlled trials evaluating cognitive training and remediation interventions among patients with MDD. A total of 15 studies met the inclusion criteria.
The patients received cognitive rehabilitation (n=410) or control interventions (n=339). For the active interventions, 9 studies used cognitive training and 6 used cognitive remediation.
The active intervention had a significant effect on the pooled outcomes of attention, executive function, verbal learning, and working memory (d, 0.61; 95% CI, 0.07-1.16; P =.02). However, after removing 1 outlier study, the effect was no longer significant (d, 0.32; 95% CI, -0.01 to 0.66; I2, 0.00%; P =.058).
Stratified by individual outcomes, cognitive rehabilitation had a significant effect on verbal learning (d, 0.94; 95% CI, 0.15-1.73; I2, 83%; P =.01), executive function (d, 0.59; 95% CI, 0.25-0.93; I2, 15.2%; P =.001), and working memory (d, 0.41; 95% CI, 0.18-0.64; I2, 33%; P <.001).
Compared with control, cognitive rehabilitation did not significantly affect MDD symptom severity (d, 0.09; 95% CI, -0.06 to 0.25; I2, 0.00%; P =.23).
In the subgroup analysis, severity of MDD symptoms did not differ significantly between intervention and control cohorts in studies that used a cognitive remediation (d, 0.21; 95% CI, -0.16 to 0.6; I2, 0.00%; P =.26) or cognitive training (d, 0.06; 95% CI, -0.12 to 0.25; I2, 11%; P =.5) intervention.
The limitations of this analysis included the different follow-up durations of the studies, the fact that only 3 studies completed a follow-up, and that many studies did not provide a history of MDD treatments.
Study authors concluded, “Cognitive rehabilitation is an effective intervention for the executive function, verbal learning, and working memory of MDD patients. Due to the importance of these neuropsychological deficits in day-to-day life and the core symptoms of MDD, cognitive rehabilitation should be considered an important part of treating MDD. Further research in this area and concentrated on these particular deficits is warranted.”
Mokhtari S, Mokhtari A, Bakizadeh F, Moradi A, Shalbafan M. Cognitive rehabilitation for improving cognitive functions and reducing the severity of depressive symptoms in adult patients with major depressive disorder: a systematic review and meta‑analysis of randomized controlled clinical trials. BMC Psychiatry. 2023;23(1):77. doi:10.1186/s12888-023-04554-w