Posttraumatic stress disorder in serving Australian Defence Force members 2002–2023: a systematic evidence review

<b>Background:</b> Defence forces globally face recruitment and retention challenges, with posttraumatic stress disorder (PTSD) often contributing to early discharge. <b>Objective:</b> To systematically review the extent of research on PTSD among Australian Defence Force (ADF) members, focusing on epidemiology, comorbidities, screening tools, and treatment outcomes to establish the evidence base and inform longitudinal research over the life course. <b>Method:</b> Following PRISMA-ScR guidelines, five databases were searched (2002–2023). Studies were included if they examined PTSD among current-serving ADF members. Screening and risk of bias assessments were conducted independently by two reviewers. Data were charted using a standardised form to extract study design, population, outcomes, and key findings. <b>Results:</b> Forty-three studies met inclusion criteria (20 low risk, 17 moderate risk, 6 high risk of bias). Twenty studies reported prevalence, eight examined comorbidities, four evaluated screening tools, and three investigated treatments. PTSD prevalence from structured diagnostic interviews ranged 2-8%, aligning with international estimates. Research on comorbidity identified associations with problem gambling, musculoskeletal disorders, hypertension, and depression. Risk factors included deployment frequency and adverse childhood events. A brief depression screen showed utility for detecting PTSD. Treatment evidence for diagnosed PTSD comprised one randomised controlled trial demonstrating non-inferiority of massed prolonged exposure therapy, and an observational study which found that baseline anger was associated with treatment outcomes. <b>Conclusions:</b> Research on PTSD among ADF members is extensive for prevalence but limited for treatments and longitudinal outcomes. The synthesised evidence reveals associations with physical health conditions and risk-taking behaviours that may compound over time, yet critical gaps include absence of incidence data and limited understanding of symptom trajectories across military careers and civilian transition. Future research should adopt two-phase epidemiological approaches with extended follow-up to establish incidence and PTSD symptom trajectories, prioritise treatment intervention studies, and investigate whether early intervention targeting risk factors prevents PTSD onset and persistence. PTSD prevalence among current-serving ADF members ranges from 2-8% based on structured diagnostic interviews, aligning with international estimates.Critical research gaps exist, including absence of incidence data and limited understanding of PTSD symptom trajectories across military careers.Future priorities include two-phase epidemiological designs with longitudinal follow-up to establish incidence and trajectories of PTSD onset, progression and recovery; treatment intervention studies; and investigation of whether targeting risk factors prevents onset and persistence of PTSD. PTSD prevalence among current-serving ADF members ranges from 2-8% based on structured diagnostic interviews, aligning with international estimates. Critical research gaps exist, including absence of incidence data and limited understanding of PTSD symptom trajectories across military careers. Future priorities include two-phase epidemiological designs with longitudinal follow-up to establish incidence and trajectories of PTSD onset, progression and recovery; treatment intervention studies; and investigation of whether targeting risk factors prevents onset and persistence of PTSD.