FC Brigitte Lueger Schuster Speaker 

Brigitte Lueger-Schuster  

Faculty of Psychology, University of Vienna
Institute of Applied Psychology: Health, Development, Enhancement and Intervention


Trauma and Traumatic Sequelae in People With Intellectual Disabilities

There is evidence pointing to a greater risk for people with Intellectual Disability (PWID) of being exposed to traumatic events (TE), especially interpersonal trauma (Wigham & Emerson, 2015). Among the most prominent risk factors, members of this population are often marginalized and vulnerable, they are separated from their parents early in life to live in service facilities.

Life events (LE) not defined as traumatic by the DSM-5 might also lead to pathological trauma sequelae in PWID. However, LEs play an important and relevant role in the development of mental illnesses in the population with ID. LEs functioning as risk factors have to be disentangled from specific LEs that cause pathological trauma sequelae. The importance of daily hassles in this population has been highlighted, as PWID may rate them as more impactful compared to their peers without ID. It can be assumed that LEs, e.g. bereavement, transfer to a new service facility, educational measures (e.g. safety room), and developmentally inappropriate experiences might lead to pathological sequelae. No study so far has investigated the variety of LEs and TEs in the population with ID, and the accumulation of multiple adverse events is highly under-researched in this population.

Traumatic Exposure

Sexual abuse is the TE with the most evidence in PWID (Wigham, Hatton, & Taylor, 2011b). In a qualitative study, PWID perceived and described victimization and the psychological aftermath more or less precisely and with strong emotions. The main response were feelings of being de-evaluated, helpless and hopeless. Most participants perceived sexual abuse as the worst form of abuse. Notably, for TEs other than sexual abuse only very little research exists (Berger, Gelkopf, Versano-Mor, & Shpigelman, 2015). Furthermore, the range of TEs as described in DSM-5 (American Psychiatric Association, 2013) accounting for PTSD might differ from the general population (GP), due to limitations in coping, memory integration, emotional processing, and functional assessment, which are all related to diagnostic overshadowing. Therefore, it is unclear whether TEs as described in DSM-5 (APA, 2013) are a valid concept for PWID. Although the DM-ID 2 was recently published with adapted criteria for PTSD, only limited evidence for the adaption was given (Blanco, McCarthy, Razza, & Tomasulo, 2016).


Prevalence of victimization in PWID is elevated compared to the GP. PWID are more prone to interpersonal victimization by multiple perpetrators, especially sexual victimization. In their meta-analysis, Jones et al. (2012) showed that 26.7% of children with ID experienced combined physical and sexual violence, 20.4% were exposed to physical violence, and 13.7% to sexual violence. The odd ratios ranged between 2.8 for sexual violence and 3.68 for combined violence. The existing studies are limited by a lack of sufficient measurements, the quality of study designs, and poor scientific standards in general, such as including a vast heterogeneity of disabilities as well as traumatic events (Jones et al., 2012). Moreover, most existing studies focus on abuse, whereas further TEs have been excluded so far.

Risk Factors

The risk of developing PTSD is exacerbated by aspects such as lower cognitive abilities and therefore difficulties in memory integration, fewer possibilities for disclosure and therefore limited social support, and a lack of specific treatment. PWID are more vulnerable to social determinants of poor health, such as poor housing and lower income. They often grow up marginalized and in service facilities, receiving no training for mastering negative life events. Moreover, societal stigma and discrimination, negative traditional beliefs, ignorance within communities, and a lack of social support for caregivers are important risk factors in this population for developing PTSD. Moreover, dependency on personal assistance, and reduced physical and emotional defenses hamper reporting of violence. Early separation from parents and placement in service facilities may contribute to a loss of protective factors. In Austria, a substantial number of adult individuals with ID live in service facilities, most of them since early childhood, under the perspective of providing and enhancing a safe environment, to stimulate the compensation of the developmental deficits. On the other hand, housing in service facilities brings the inherent risk for PWID to be victimized by caregivers or being exposed to interpersonal trauma caused by external people that caregivers are unable to identify. To date, no scientific evidence for such potential TEs is available.

Institutional abuse

In several European countries, the US, Australia and Canada, adults (of the GP) claimed financial redress and apologies for violent acts committed by members of institutions. The placement in institution took place for several reasons, such as elite education or foster care. Commissions were established to conduct investigations, along with scientific studies. Institutional abuse (IA) is defined as any kind of physical, emotional or sexual violence and neglect that happen within an institution (Lueger-Schuster et al., 2014). Multiple exposures to traumatic experiences (polyvictimization), a delay in disclosure (Lueger-Schuster et al., 2015), and an elevated psychopathological response in non-PWID survivors of institutional abuse from the GP (Lueger-Schuster et al., 2014; Lueger-Schuster et al., 2015) have been repeatedly reported. Clearly, there is need for studies on the PWID community exploring the prevalence of TEs inside and outside of institutions, and the resulting traumatic sequelae.

Posttraumatic Stress Reactions, Emotional Responses, Expressing of Symptoms

PTSD core symptoms and expression of symptoms

The core symptoms of PTSD in the GP are defined as re-experiencing, avoidance, negative alterations in cognitions and mood, and hyperarousal. Currently, the DSM-5 (American Psychiatric Association, 2013) lists 20 symptoms in four groups, whereas the proposed ICD-11 includes six symptoms in three groups. However, little is known about the expression of symptoms in PWID. The main difference is a preponderance of behavioral symptoms which are often not recognized as PTSD indicators. For example, challenging and aggressive behaviors are mostly interpreted in the light of the ID diagnosis itself, leading to a phenomenon referred to as diagnostic overshadowing (Mason & Scior, 2004), indicating that diagnostic overshadowing might cause a bias of reported PTSD rates with psychological problems and disorders not being adequately related to TEs, and therefore not being recognized. Challenging behaviors are defined as behaviors that are deemed to be challenging by caregivers or families, including behaviors such as aggression, self-injury, screaming, disturbed sleep patterns, and hyperactivity. They might be seen as an expression of traumatic symptoms, which are defined as an adaptive reaction towards a situation out of the range of normality. However, the question remains whether challenging behavior in PWID is an expression of the traumatic sequelae or a more general behavior occurring with any kind of irritation.

Additional symptoms and diagnostic criteria

Research in this domain is being further complicated by the current reformulations of stress-related disorders in both classification systems. However, the proposed introduction of Complex PTSD (CPTSD) in the ICD-11 (Maercker et al., 2013) might increase the chance to identify PWID with a traumatic stress disorder, since the additional symptoms of the CPTSD (three dimensions of disturbances in self-organization [DSO], affect dysregulation, negative self-concept and disturbances in relationships) have to be present together with three symptoms of PTSD (re-experiencing, avoidance, sense of threat) in PWID with traumatic stress disorders. The CPTSD diagnosis is defined as a sibling diagnosis (Maercker et al., 2013). Wigham et al. (2011b) reviewed the literature systematically and they found that the DSO symptoms are also present in PWID as a trauma sequelae. However, the newly proposed classification is based on the idea of clinical utility and helps to avoid comorbidities. The principle of clinical utility might be more adequate for PWID.


Recently developed assessment tools (Hall, Jobson, & Langdon, 2014; Wigham, Hatton, & Taylor, 2011a) give the possibility to learn more about the specific trauma-related symptoms, and provide an assessment tool that enables caretakers, parents and of course the individuals with ID to identify the trauma sequelae, to respond to their trauma-related needs, even though they are limited in their quality. These instruments measure general effects of trauma (Wigham et al., 2011a) and are available only in English language. Instruments existing so far need improvements and an adaption for PWID with severe cognitive problems. 


Currently, promising studies for PWID suffering from traumatic sequelae are conducted, using e.g. EMDR. So far, no solely anecdotal evidence is given.


American Association on Intellectual and Developmental Disabilities. (2010). Intellectual disability: Definition, classification, and systems of supports (11th ed.). Washington, DC: American Association on Intellectual and Developmental Disabilities.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (DSM-5®) (5th ed.). Washington: American Psychiatric Publishing.

Berger, R., Gelkopf, M., Versano-Mor, K., & Shpigelman, C.-N. (2015). Impact of exposure to potentially traumatic events on individuals with intellectual disability. American journal on intellectual and developmental disabilities, 120(2), 176–188. doi:10.1352/1944-7558-120.2.176

Blanco, R., McCarthy, J., Razza, N. J., & Tomasulo, D. J. (2016). Trauma- and stressor related disorders. In R. J. Fletcher (Ed.), DM-ID 2. Diagnostic manual - intellectual disability. A textbook of diagnosis of mental disorders in persons with intellectual disabilities (2nd ed., pp. 353–400). Kingston N.Y.: NADD Press.

Hall, J. C., Jobson, L., & Langdon, P. E. (2014). Measuring symptoms of post-traumatic stress disorder in people with intellectual disabilities: The development and psychometric properties of the Impact of Event Scale-Intellectual Disabilities (IES-IDs). The British Journal of Clinical Psychology, 53(3), 315–332. doi:10.1111/bjc.12048

Jones, L., Bellis, M. A., Wood, S., Hughes, K., McCoy, E., Eckley, L.,. . . Officer, A. (2012). Prevalence and risk of violence against children with disabilities: A systematic review and meta-analysis of observational studies. The Lancet, 380(9845), 899–907. doi:10.1016/S0140-6736(12)60692-8

Lueger-Schuster, B., Butollo, A., Moy, Y., Jagsch, R., Gluck, T., Kantor, V.,. . . Weindl, D. (2015). Aspects of social support and disclosure in the context of institutional abuse - long-term impact on mental health. BMC Psychology, 3(1), 19. doi:10.1186/s40359-015-0077-0

Lueger-Schuster, B., Kantor, V., Weindl, D., Knefel, M., Moy, Y., Butollo, A.,. . . Gluck, T. (2014). Institutional abuse of children in the Austrian Catholic Church: Types of abuse and impact on adult survivors' current mental health. Child Abuse & Neglect, 38(1), 52–64. doi:10.1016/j.chiabu.2013.07.013

Maercker, A., Brewin, C. R., Bryant, R. A., Cloitre, M., Reed, G. M., van Ommeren, M.,. . . Saxena, S. (2013). Proposals for mental disorders specifically associated with stress in the International Classification of Diseases-11. The Lancet, 381, 1683–1685. doi:10.1016/S0140-6736(12)62191-6

Mason, J., & Scior, K. (2004). 'Diagnostic overshadowing' amongst clinicians working with people with intellectual disabilities in the UK. Journal of Applied Research in Intellectual Disabilities, 17(2), 85–90. doi:10.1111/j.1360-2322.2004.00184.x

Wigham, S., Hatton, C., & Taylor, J. L. (2011a). The Lancaster and Northgate Trauma Scales (LANTS): The development and psychometric properties of a measure of trauma for people with mild to moderate intellectual disabilities. Research in Developmental Disabilities, 32(6), 2651–2659. doi:10.1016/j.ridd.2011.06.008

Wigham, S., Hatton, C., & Taylor, J. L. (2011b). The effects of traumatizing life events on people with intellectual disabilities: A systematic review. Journal of Mental Health Research in Intellectual Disabilities, 4(1), 19–39. doi:10.1080/19315864.2010.534576