What’s the relationship between autism and trauma?
Over the past few decades, both autism and trauma have become better understood and more frequently diagnosed. Researchers, clinicians, and autistic people themselves all perceive a relationship between autism and trauma. However, we don’t yet know why or how they’re related. A variety of explanations have been proposed:
- Do autistic children face more bullying and abuse, which is traumatizing?
- Does growing up autistic in a neurotypical world cause trauma?
- Does something about autism lead everyday stressors (like changes in routine) to become traumatic?
- Is autism a type of response to trauma? (That is, is autism itself a trauma disorder?)
- Do autism and trauma simply look similar?
Autistic adults prioritize research on these issues . Yet, answers are only beginning to emerge.
What is trauma?
The DSM-5 defines a family of disorders caused by exposure to “traumatic events,” such as witnessing violence or death . These trauma disorders include PTSD, Reactive Attachment Disorder, and Acute Stress Disorder.
In PTSD, a person older than six years old:
- Has at least one intrusion symptom, where a person persistently re-experiences the traumatic event (for example, nightmares, flashbacks);
- Avoids reminders of the trauma, either thoughts and feelings or external reminders;
- Worsening thoughts and mood in at least 2 ways (such as being unable to recall key facts about the trauma; blaming self or others for causing it; difficulty experiencing positive feelings, etc.).
- Becomes more reactive after the trauma (for example, hypervigilance, aggressiveness);
- The changes last for more than 1 month and distress or impair the person.
(There are separate criteria for children aged six or younger).
Not all children exposed to traumatic events meet criteria for these disorders, but they may still experience physical and emotional distress, poor school performance, impaired cognition, and impulsive behavior . These negative reactions are called “trauma.”
That is the reason I am discussing “trauma” rather than “trauma disorders.” Autism may be related to people’s responses to traumatic events, whether or not those are severe enough to be diagnosed as a trauma disorder.
You may notice I’m talking about children. That’s because the roots of both autism and trauma often go back to childhood, and because much of the research focuses on children. As far as I know, there’s no reason to think the relationship between autism and trauma is fundamentally different for adults.
Why might autism be related to trauma?
Children with autism are more likely to experience abuse
First, autism may increase children’s exposure to traumatic events  and adverse childhood events . Adverse childhood experiences (ACEs) do not directly cause trauma disorders, but are risk factors for chronic health problems, mental illness, substance misuse, and underemployment in adulthood . ACEs include low family income, frequent moves, parental divorce, parent mental illness or addiction, and experiencing racism. The greater the number of ACES, the higher the risk for psychiatric and mental health problems .
Children with autism spectrum disorder (ASD) and intellectual disability (ID) are more likely than others to be abused or neglected. A large-scale study found that reported and substantiated abuse were almost two and a half times more likely among children with autism and ID . For those with autism but not ID, reported abuse was almost twice as common and substantiated abuse was one and a half times more likely. Looking more finely at different type of abuse, children with ASD and no ID were more likely to experience physical abuse, and those with both ASD and ID were more likely to experience all forms of abuse. Regardless of IQ, children with ASD were more likely to experience physical neglect. 
However, not all studies agree. Hoover and Kaufman did not find evidence for such maltreatment .
Autistic children may also be more vulnerable to trauma because they experience more bullying . Bullying is an ACE that lowers children’s academic functioning and mental health, and increases their suicide risk . Hoover & Kaufman found that children with ASD were three to four times more likely than non-disabled children to be bullied by peers .
Growing up autistic can be traumatizing
Children with ASD may experience some everyday events as traumatic, which would not have lasting effects on typically developing children.
Sensory sensitivity may make everyday stimuli, such as loud noises, painful or threatening .
Social demands may appear more threatening to children with ASD, who are less able to meet them . Even a peer asking them to play causes physiological stress for children with ASD .
Abrupt changes in routine may also be experienced as traumatic . Even for typically developing children who have experienced trauma, teachers are advised to keep routines and expectations consistent .
Autistic adults argue that the most common intervention for ASD, Applied Behavior Analysis, traumatizes children who experience it. A study by Kupferstein supports this idea . So, not only autism itself, but attempts to treat it, may cause trauma.
Finally, children with ASD may be more susceptible to trauma because they have less support from others. Social support reduces the effects of traumatic events .
How common is trauma for children on the spectrum?
It is unclear how many children with ASD experience trauma or trauma disorders. Reported rates vary. One study found none were diagnosed with PTSD , compared to two thirds in another study [12, 7]. It depends on where researchers recruit their participants. It also depends on whether they look for a history of abuse and neglect or a PTSD diagnosis. There are many more children with a history of abuse and neglect than with a PTSD diagnosis.
Why don’t we know more?
Biases within autism research
One reason we know so little about the relationship between autism and trauma is the history of autism research.
When autism was first described in the 1950’s it was interpreted within a psychoanalytic framework. Cold parenting (“refrigerator mothers”) were blamed for children’s social and emotional difficulties. Parents already faced a lot of stigma, and being blamed by professionals made it worse.
When it became clear autism was a highly heritable developmental disability, psychologists went out of their way to avoid blaming parents. In doing so, they left the role of parenting practices in ASD children’s development largely unstudied.
Thus, research on ASD and PTSD among children proceeded separately, while both were diagnosed increasingly often, until the 2000’s.
Another reason for our ignorance is that PTSD is underreported in ASD — especially when caregivers are the informants . Furthermore, ASD symptoms may make it harder for children to report traumatic events that happen to them, including to their caregivers .
Signs of autism and PTSD overlap
PTSD symptoms may be misperceived as merely intensified ASD traits (autism becoming “more severe”)[12, 3].
After traumatic events, children’s social, communication, and self care skills decrease, while their aggression, distractibility, agitation, sleep disorders, hyperactivity, self-injury, and stereotyped behavior increase. Also, children with ASD who experience mistreatment are more likely to exhibit aggression, hyperactivity, and tantrums .
All of these difficulties are associated with autism.
PTSD symptoms may be misattributed to autism because trauma and ASD symptoms overlap.
Children with both disabilities often avoid or are anxious about seemingly innocuous places, people, or objects. For children with a PTSD diagnosis, these feared things are seen as “associated with trauma;” for those with an ASD diagnosis, they may be assumed to be unpleasant to the senses.
Intrusive recurring thoughts characteristic of PTSD may be interpreted as restricted interests.
Night terrors and sleep disturbances associated with PTSD may be seen as the insomnia that affects 40–80% of those with ASD.
Avoidance of comfort seeking and lack of social and emotional responsiveness are seen in both Reactive Attachment Disorder and ASD. (Hoch & Youssef, 2020).
PTSD is known to involve triggered fight, flight, or freeze responses. In the DSM-5, children aged 6 and younger exhibit “irritable behavior and angry outbursts (including extreme temper tantrums)” . Meltdowns in ASD are triggered fight responses, or may occur when attempts to flee fail. The DSM-5 lists hypervigilance and an exaggerated startle response as symptoms of childhood PTSD. Both occur in autism, and have been linked to sensory processing differences .
What do we know so far?
Autistic children are exposed to more ACEs than typically developing peers, especially bullying. That reduces autistic children’s mental health and makes them more likely to develop PTSD.
If anything, studies might be underestimating the number of autistic children with PTSD. Children may not be able to report what happened to them, while parents and professionals attribute their reactions to autism. These factors can lead some children’s PTSD to be missed.
It’s possible that a broader range of experiences are traumatizing for children with ASD. Furthermore, the way autistic children are treated is often traumatizing. However, causal explanations like these have only recently been studied. It’s not clear whether either explanation is true.
In short: we know there’s a relationship between autism, trauma, and PTSD. We just don’t know why. Stay tuned.
 Benevides, T.W., et al. (2020). Listening to the autistic voice: Mental health priorities to guide research and practice in autism from a stakeholder-driven project. Autism, 24(4) 822–833. DOI: 10.1177/1362361320908410
 American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: Author.
 Haruvi-Lamdan, N., Horesh, D., & Golan, O. (2018). PTSD and autism spectrum disorder: Comorbidity, gaps in research, & potential shared mechanisms. Psychological Trauma: Theory, Research, Practice, & Policy, 10(3), 290–99.
 Hoover, D.W., & Kaufman, J. (2018). Adverse childhood experiences in children with Autism Spectrum Disorder. Current Opinion in Psychiatry, 31(2), 128–132. doi: 10.1097/YCO.0000000000000390.
 National Center for Injury Prevention and Control, Division of Violence Prevention (2020). Preventing Adverse Childhood Experiences. U.S. Center for Disease Control. <https://www.cdc.gov/violenceprevention/aces/fastfact.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fviolenceprevention%2Facestudy%2Ffastfact.html> Accessed: 11/11/20
 McDonnell, C. G., Boan, A. D., Bradley, C. C., Seay, K. D., Charles, J. M., & Carpenter, L. A. (2019). Child maltreatment in autism spectrum disorder and intellectual disability: results from a population‐based sample. Journal of child psychology and psychiatry, 60(5), 576–584.
 Hoch, J. D., & Youssef, A. M. (2020). Predictors of Trauma Exposure and Trauma Diagnoses for Children with Autism and Developmental Disorders Served in a Community Mental Health Clinic. J. of Autism and Developmental Disorders, 50(2), 634–649.
 Corbett, B.A., Schupp, C.W., Simon, D. et al. (2010). Elevated cortisol during play is associated with age and social engagement in children with autism. Molecular Autism, 1 (13). https://doi.org/10.1186/2040-2392-1-13
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 Kupferstein, H. (2018). Evidence of increased PTSD symptoms in autistics exposed to applied behavior analysis. Advances in Autism.
 DeBruin, E.I., Ferdinand, R.F., Meester, S., de Nijs, P.F., & Verheij, F. (2007). High rates of psychiatric comorbidity in PDD-NOS. J. of Autism & Developmental Disorders, 37, 877–86.
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 Takahashi, H., Komatsu, S., Nakahachi, T., Ogino, K., & Kamio, Y. (2016). Relationship of the acoustic startle response and its modulation to emotional and behavioral problems in typical development children and those with autism spectrum disorders. Journal of autism and developmental disorders, 46(2), 534–543.