The Role of Posttraumatic Stress Disorder as a Risk Factor for Dementia: A Meta-Analysis

BackgroundDementia is a growing global health concern, particularly among individuals with Posttraumatic Stress Disorder (PTSD), which may be a potential risk factor. However, the effects of moderating factors remain unclear.PurposeThis study aims to assess the relationship between PTSD and dementia risk, including potential moderators. Research designA systematic literature review and meta-analysis were conducted in PubMed, CINAHL, PsycINFO, The Cochrane Library, and Scopus.Data analysisRandom-effects meta-analyses were performed separately for unadjusted risk ratios (RRs) calculated from raw data and adjusted hazard ratios (HRs) reported from survival analyses. Subgroup and moderator analyses examined effects of population type, study quality, demographics, health and lifestyle factors on the PTSD-dementia association.Study sampleEighteen studies were included after screening 30,203 abstracts and 621 full-text articles.ResultsPTSD was associated with a 43% (unadjusted pooled RR = 1.43, 95% CI:1.09-1.89, I² = 99.22%, <i>P</i> = 0.011) and 56% (adjusted pooled HR = 1.56, 95% CI:1.27-1.91, I² = 95.50%, <i>P</i> < 0.001) increased dementia risk. Diabetes and hypertension strengthened the association, whereas depression, traumatic brain injury, and drinking alcohol might weaken it. However, post hoc analyses indicated that the moderation effects of depression and alcohol use were not significant after excluding one influential study. No moderating effects were found for age, gender, population type or race, and no evidence of publication bias was detected.ConclusionsThese findings confirm PTSD as a significant risk factor for dementia, with diabetes and hypertension potentially increasing vulnerability. Depression and alcohol use initially appeared to attenuate the association, but these effects were not robust in post-hoc analyses. Further research is needed to identify potential moderators and develop targeted interventions.