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

Background Dementia 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. Purpose This study aims to assess the relationship between PTSD and dementia risk, including potential moderators. Research design A systematic literature review and meta-analysis were conducted in PubMed, CINAHL, PsycINFO, The Cochrane Library, and Scopus. Data analysis Random-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 sample Eighteen studies were included after screening 30,203 abstracts and 621 full-text articles. Results PTSD was associated with a 43% (unadjusted pooled RR = 1.43, 95% CI:1.09-1.89, I 2 = 99.22%, P = 0.011) and 56% (adjusted pooled HR = 1.56, 95% CI:1.27-1.91, I 2 = 95.50%, P < 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. Conclusions These 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.