Traumatic life events and risk for dementia: a systematic review and meta-analysis

OBJECTIVES: To systematically review the association between traumatic life events (TLE) and dementia risk. DESIGN: Systematic review and meta-analysis. DATA SOURCES: APA, PsychINFO, Embase and MEDLINE from their inception to 29.05.21 and updated on 20.04.22. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Original research articles published in peer reviewed journals examining the association between TLE and all cause dementia in individuals aged 60 and over. Two researchers independently assessed the risk of bias using the Newcastle–Ottawa Scale. We conducted a generic inverse variance random effects meta-analysis to provide an overall estimate of TLE impact on dementia risk. MAIN OUTCOME MEASURES: Risk, odds and hazards ratios relating to dementia risk. RESULTS: Initially, 3,487 studies were retrieved in the search and seven studies were included in the meta-analysis with data being used from 276,570 participants. TLE were associated with increased dementia risk. Trauma in general had a pooled HR of 1.21, (95% CI 1.03, 1.43, P = 0.0001). War/ Holocaust trauma and childhood trauma were also associated with increased dementia risk (HR = 1.28 (95% CI 1.01–1.63, P = 0.02) and HR = 1.76 (95% CI 1.17–2.64, P = 0.007) respectively). CONCLUSIONS: We have found an association between TLE and dementia risk. Future research exploring the dimensions of TLE and individual level factors are needed to better understand the relationship between TLE and dementia. TRIAL REGISTRATION: PROSPERO CRD42021253090. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-04287-1.