Computerized Cognitive Training in People with Depression: A Systematic Review and Meta-analysis of Randomized Clinical Trials

ImportanceCognitive impairment is a common feature of both symptomatic and remitted states of depression that is associated with poorer psychosocial outcomes and treatment non-response. As such, finding treatments to maintain or enhance cognition in people with depression is imperative. ObjectiveTo investigate the efficacy and moderators of computerized cognitive training (CCT) for cognitive and functional outcomes in people with depression. Data SourcesMEDLINE, EMBASE and PsycINFO databases were screened from inception through to 08 September 2022, with no language or publication type restrictions. Study SelectionTwo independent reviewers conducted duplicate study screening and assessed against the following inclusion criteria: (1) adults (mean age 18 years or older) with depression, (2) CCT with minimum three hours practice, (3) active or passive control group, (4) cognitive and/or functional outcomes measured at baseline and post-intervention, (5) randomized controlled trials. Of 4245 identified studies, 34 met selection criteria. Data Extraction and SynthesisThe methods used followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data extraction and risk of bias assessment using the revised Cochrane Risk of Bias Tool (RoB2) was conducted independently by two reviewers. Analyses were conducted using robust variance estimation. OutcomesThe primary outcome was change from baseline to post-intervention in overall cognition. Secondary outcomes were depressive symptoms, psychiatric symptoms, psychosocial functioning, daily functioning, subjective cognition, global cognition and domain-specific cognitive function. ResultsThirty-four studies encompassing 39 comparisons and 2041 unique participants met inclusion criteria. The pooled effect size of CCT was small for both overall cognition (g=0.28; 95% CI 0.17 to 0.38; P<.001; {tau}2=0.078; I2=47%; 95% prediction interval -0.31 to 0.86) and depressive symptoms (g=0.23; 95% CI 0.08 to 0.39; P=.004; {tau}2=0.066; I2=45%; 95% prediction interval -0.32 to 0.78). Benefits of CCT were also found for psychosocial functioning, subjective cognition, fluid reasoning, long-term memory and retrieval, low working memory, shifting, inhibition and processing speed. Greater CCT dose and multidomain programs were associated with greater cognitive response to CCT. There was no evidence for difference across clinical subtypes or between delivery modalities. Conclusions and RelevanceThis systematic review and meta-analysis indicates that CCT is an efficacious intervention for overall cognition, depressive symptoms, psychosocial functioning, subjective cognition, and many domain-specific cognitive functions for people with depression.