Overview

• Researchers performed an umbrella review and meta-analysis on existing systematic reviews and added recent studies to clarify the timing of depression’s impact on dementia risk.
• The analysis confirmed that depressive episodes in both midlife and late life substantially increase the likelihood of developing dementia.
• Chronic inflammation, stress-hormone dysregulation, vascular dysfunction, and neurochemical imbalances were identified as key biological links between depression and cognitive decline.
• Findings suggest that depression emerging later in life may represent an early sign of dementia rather than solely a risk factor.
• The study underlines the need for enhanced mental health screening and treatment across the lifespan to support dementia prevention efforts.