Prevalence of Complex Post-Traumatic Stress Disorder in Serving Military and Veteran Populations: A Systematic Review.

Serving military personnel and veterans are known to be at elevated risk of post-traumatic stress disorder (PTSD), and some veterans have been shown to respond poorly to current standard treatments. Evidence so far suggests that according to the 11th edition of the International Classification of Diseases and Related Health Problems guidelines, complex PTSD (CPTSD) may be of higher prevalence in the general population than PTSD. The aim of the study was to investigate the prevalence of CPTSD compared to PTSD in serving and ex-serving military populations. A systematic review was conducted with the search criteria set to peer-reviewed English language journal articles, focusing on serving military or veteran populations, reporting on the prevalence of CPTSD, not restricted by year. Four comprehensive databases (Psycinfo, Pubmed, CINAHL, and Embase) were searched. Of the 297 identified articles, 16 primary studies were eligible for inclusion. The review was registered in the PROSPERO database (CRD42023416458), and results were reported based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of the 16 studies, 13 demonstrated higher prevalence of CPTSD than PTSD. Studies were predominantly veteran focused. Prevalence of CPTSD ranged from 5% to 80.63%, while prevalence of PTSD ranged from 3.8% to 42.37%. There was high heterogeneity in study populations, preventing meta-analysis. This is the first systematic review to assess the prevalence of CPTSD in serving military and veteran populations, with the findings demonstrating a higher rate of CPTSD compared to PTSD. It is hoped that the review will assist clinicians and military and veteran health services with appropriate assessment, diagnosis, and intervention for those affected by CPTSD, as well as PTSD.