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Ascertainment and Prevalence of Post-Traumatic Stress Disorder (PTSD) in People with Intellectual Disabilities

Prof Cornelius Katona
John Daveney, Angela Hassiotis, Faith Matcham & Piyal Sen
Journal of Mental Health Research in Intellectual Disabilities



Post-traumatic stress disorder (PTSD) may be under-recognized in people with intellectual disabilities (PWID) and reviews on appropriate screening tools and prevalence are lacking.

This review aims to identify PTSD screening tools for PWID and estimate the prevalence of PTSD within this population. 


Medline, PubMed, Embase, PsycINFO, Cochrane, Global Health, and Web of Science databases were searched (inception to October 2017) to identify eligible literature. Papers were also found via manual searches of the references of eligible studies.

Studies were reviewed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines, subjected to exclusion criteria and quality appraised using STROBE criteria for observational studies and an adapted form of the Newcastle-Ottawa scale for cross-sectional studies. Seven studies were identified. Meta-analysis was carried out on the prevalence studies and heterogeneity quantified using I2.


Three tools for screening PTSD in PWID were found: two for use in adults (the Lancaster and Northgate Trauma Scale and the Impact of Event Scale – Intellectual Disabilities) and the Adapted Anxiety Disorders Interview Schedule for Children with PTSD. Five studies reported PTSD prevalence in PWID. The weighted pooled prevalence of PTSD in PWID was found to be 10%, 95% CI [0.4%, 19.5%], toward the upper limit of estimated PTSD prevalence in the general population (5–10%). 


PTSD can be diagnosed in PWID but may go unrecognized by health-care professionals.

The identified tools should be further compared and assessed for acceptability and efficacy to improve the identification of PTSD in PWID.