Depression in Mid and Late-Life Linked to Increased Dementia Risk

Depression in mid and late-life is linked to an increased risk of dementia, according to new research published in eClinicalMedicine. 

“Our findings raise the possibility that depression late in life may not just be a risk factor, but it could also be an early warning sign of dementia beginning to develop,” said lead author Jacob Brain, Institute of Mental Health, The University of Nottingham Medical School, Nottingham, UK, in a news release. “By clarifying this timing, our work helps guide future research, treatment, and prevention strategies.”

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The researchers first conducted an umbrella review of 9 systematic reviews with meta-analyses that assessed the association between depression and the incident risk of late-life dementia. Using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR2) criteria, the reviews were rated as being of moderate (n = 1), low (3), and critically low (n = 5) quality. The baseline mean age of participants ranged from 52.7 to 83.8 years. 

The authors then conducted a meta-analysis of 18 individual studies reporting on depression onset in later life (n = 901,762 participants, n = 7595 incident dementia cases) and 7 individual studies on depression onset in midlife (n ≥ 2,501,269 participants, n ≥ 276,929 incident dementia cases). All the studies in the meta-analysis were rated as good quality. Researchers extracted data from the included studies and reported dementia risk as hazard ratios (HRs), then used random-effects models to generate pooled estimates. 

Based on the analysis, depression present in midlife (HR 1.56, 95% CI: 1.12–2.18; I2 = 97.5%) and late-life (HR 1.95, 95% CI: 1.68–2.26; I2 = 77.5%) significantly increased the risk of all-cause dementia. 

"This highlights the importance of recognizing and treating depression across the life course, not just for mental health, but also as part of a broader strategy to protect brain health,” Brain continued. 

The authors suggest that future research examine how treatment effects, recurrence and remission patterns, and the life course characteristics of depression impact dementia risk to better understand the relationship between the disorders. 
 

References
Brain J, et al. Temporal dynamics in the association between depression and dementia: an umbrella review and meta-analysis. eClinicalMedicine. Published online ahead of print June 2025. doi:10.1016/j.eclinm.2024.103266

Depression is linked to an increased risk of dementia in both mid and later life, finds a new study. News release. EurekaAlert. May 29, 2025. Accessed June 5, 2025.