Abstract
Introduction:
With population aging comes challenges like dementia, prompting the urgent identification of risk factors and its associations with other psychiatric disorders. This review aims to explore the connection between depression and the onset of mild cognitive impairment (MCI) or dementia through recent literature analysis.
Methods:
Systematic review and meta-analysis, following PRISMA recommendations, with studies from 2013 onwards. The search strategy “Depression” AND “Dementia” AND “Aged” was employed in the Cochrane, Embase, LILACS, PubMed, Scopus, and Scielo databases. Cohort studies in Portuguese, English, or Spanish were included, while reviews or clinical trials were excluded.The meta-analysis was conducted using RevMan software, employing unadjusted OR effect measures for exposure in the Forest Plot graph. Study heterogeneity was calculated using the I² statistic, with a cutoff point of >75% indicating high heterogeneity.
Results:
The search strategy identified 3,394 articles, screened by title and abstract. Of these, 187 were fully read, and 26 were included in the review. The most used tool for assessing depressive symptoms was the Geriatric Depression Scale (38.4%), while the Mini-Mental State Examination was the most frequently used tool for assessing symptoms of MCI and dementia (26.9%). The quantitative analysis included 14 studies evaluating dementia and 8 studies evaluating MCI. The likelihood of older adults with depression developing dementia was 1.75 times higher than in the non-depressed population (OR = 1.75; 95% CI 1.46 - 2.11). Additionally, a twofold increase in the likelihood of developing MCI was found in depressed older adults (OR = 2.03; 95% CI 1.44 - 2.88). All analyses revealed high heterogeneity.
Conclusion:
Depression was found to be associated with higher likelihood of developing MCI or dementia in older adults. Understanding this complex relationship with new studies and reviews is crucial for developing targeted interventions and improving the prognosis for individuals affected by both conditions.