June is National PTSD Awareness Month

In recognition of June as National Post-Traumatic Stress Disorder Awareness Month, the National Center for START Services® is exploring the prevalence of PTSD among the people we serve with intellectual and developmental disabilities (IDD).

PTSD can develop after a person experiences or is exposed—directly or indirectly—to traumatic events that overwhelm their ability to cope. Individuals with PTSD may experience persistent, distressing thoughts, emotions, and reactions related to the traumatic event long after it has ended.

PTSD is more common than many people realize, and individuals with intellectual and developmental disabilities (IDD) are at significantly greater risk. Research suggests that between 80% and 90% of people with IDD are exposed to traumatic or adverse life events. While not everyone who experiences trauma develops PTSD, many experience lasting effects that impact their emotional, psychological, and physical well-being.

Unfortunately, PTSD is often overlooked in people with IDD due to diagnostic overshadowing—the tendency to attribute symptoms of trauma to an existing disability, another psychiatric diagnosis, or simply to “behavioral” challenges. As a result, PTSD frequently goes unrecognized and untreated.

Estimates of PTSD prevalence among people with IDD have ranged from 2.5% to 60%, reflecting inconsistencies in diagnosis and the limited availability of screening and assessment tools designed specifically for this population. A recent comprehensive review estimated a lifetime PTSD prevalence of approximately 10% among people with IDD—two to three times higher than in the general population. The authors note that this figure is likely an underestimate.

Data from our START teams further supports this concern. Approximately 12–13% of individuals referred to START enter the program with an existing PTSD diagnosis. Given that START serves a subset of people with IDD who are experiencing crises or are at high risk for crisis, the true prevalence of PTSD among those we support is likely even higher.

While we may not yet have a complete picture of PTSD prevalence in people with IDD, it is reasonable to assume that the condition remains significantly underdiagnosed. Traumatic and adverse experiences can profoundly affect how a person's brain and body respond to everyday stressors, making it essential for providers to recognize the signs and symptoms of PTSD and other trauma-related disorders. This understanding is critical to delivering effective, individualized support and treatment.

There is also reason for hope. With appropriate supports, services, and interventions, people can heal, grow, and thrive. Providing care through a trauma-informed lens is fundamental to that healing process. During PTSD Awareness Month, let us reaffirm our commitment to recognizing the impact of trauma and ensuring that individuals with IDD receive the understanding, support, and treatment they deserve.

Santambrogio, J. et.al Prevalence of mental disorders in people with intellectual disabilities across the lifespan: umbrella review. Cambridge University Press:  26 May 2026

Mevissen, L., Didden, R., de Jongh, A., & Korzilius, H. (2020). Assessing posttraumatic stress disorder in adults with mild intellectual disabilities or borderline intellectual functioning. Journal of Mental Health Research in Intellectual Disabilities,13(2), 110–126.