Prevalence of Post-Traumatic Stress Disorder (PTSD) in autistic children or young people (CYP) and adults: A systematic review and meta-analysis.

Autistic individuals are more likely to encounter traumatic events and mental health challenges throughout their lives. While multiple studies have explored the link between autism and post-traumatic stress disorder (PTSD), no meta-analysis has comprehensively synthesised PTSD prevalence rates according to DSM or ICD diagnostic manuals. This is important for ensuring appropriate intervention for this underserved population. Therefore, the current meta-analysis investigated the point and lifetime prevalence of PTSD among diagnosed autistic children or young people (CYP) and adults. A thorough systematic search identified 17 studies involving 53,918 autistic CYP and 13 studies with 142,081 autistic adults. Random-effects meta-analyses indicated a point prevalence of 1.11 % (95 % CI: 0.32; 2.38) among autistic CYP and 2.06 % (95 % CI: 0.00; 11.97) among autistic adults. Lifetime prevalence was 5.74 % (95 % CI: 2.12; 10.99) for autistic CYP and 2.72 % (95 % CI: 2.54; 2.90) for autistic adults. Subgroup analyses identified several factors influencing rates: co-occurring intellectual disability, gender proportion, diagnostic criteria (e.g., DSM vs. ICD), and informant type (self-report vs. combined self and carer/parent). Although PTSD prevalence rates are similar to general population estimates, they contrast with previous studies using screening tools, which reported substantially higher PTSD symptomatology in autistic individuals. This discrepancy may highlight some limitations of current PTSD diagnostic criteria, which may not fully capture how trauma is experienced and expressed by autistic individuals, leading to underdiagnosis and potentially significant adverse outcomes. Future research should focus on developing autism-specific diagnostic guidelines to better identify and address PTSD in this population, ensuring more timely support.