Adverse childhood experiences and risk of late-life dementia: a systematic review and meta-analysis.

backgroundAdverse childhood experiences (ACEs) refer to distressing events before age 18 that can lead to potential mental and physical health consequences. This systematic review and meta-analysis aimed to examine the association between ACEs and the risk of dementia in elderly adults who experienced ACEs during childhood, addressing the existing inconsistencies and methodological variations.

methodsA comprehensive search strategy was employed across key databases (PubMed, Web of Science, Scopus, and Embase) to identify relevant articles. Our primary outcome was ACEs-dementia risk, and our secondary outcome was mild cognitive impairment risk. A quality assessment was conducted using the Newcastle-Ottawa Quality Assessment Scale and GRADE. A random-effects model was utilized to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were performed to explore potential sources of heterogeneity and assess the reliability of the results.

resultsOut of 1,376 screened papers, nine studies were included. The studies consisted of two case-control, one prospective cohort, and six retrospective cohort studies conducted in the UK, France, USA, China, and Spain. Five studies were of good methodological quality according to the NOS. according to the GRADE, all outcomes were classified as very low or low quality of evidence. A significant association was observed between ACEs and dementia risk (OR = 1.35; 95% CI 1.20, 1.52; P = 0.00001) and mild cognitive impairment risk (OR = 1.28; 95% CI 0.63, 2.62; P = 0.49). A meta-analysis by type of adversity revealed significant results for the maltreatment subgroup(OR = 1.30; 95% CI 0.07-1.58; P = 0.007; I² = 0%). Subgroup analysis based on the dementia definition revealed no between-subgroup difference (P = 0.71) between tool-based and register/criteria-based subgroups. No possibility of Publication bias was observed upon inspection of the funnel plot.

conclusionAdverse childhood experiences may be associated with an increased risk of dementia. However, caution is warranted in interpreting these results due to the limited number of studies. Larger high-quality studies investigating the association between ACEs and dementia risk are needed to confirm the reliability of our results.