Listen to a podcast summary of Late-Diagnosed Adult Autism and Trauma
A growing body of first-hand accounts and mental health providers’ observations point towards a heightened connection between late-diagnosed autism and PTSD or C-PTSD. While the science lags behind, it is time for the mental health community, and everyone more generally, to listen to Autistic voices.
At CooperRiis, we treat low-support-needs Autistic people with any mental health challenge, diagnosed or not. We don’t focus on diagnosis. Instead, we focus on the person in front of us and the life they want for themselves. We don’t need science to prove that a person’s trauma is real before we can help them process and move past it. We know that trauma-informed care is central to autism-informed care.
We’ve Come a Long Way, But…
The experience of autism spectrum disorder (ASD) can be gentler today than in generations past. Behaviors in children that might have been derided as quirks, difficulty, or laziness are more readily seen as possible signs of ASD—and of the child’s best efforts to fit in, or mask. With early diagnosis and a supportive environment, children with ASD may now meet acceptance, understanding, and accommodation instead of othering.
But those diagnosed later in life may face a harsher reality—one of criticism, alienation, and shame—without understanding why. What’s more, masking takes a heavy cognitive and psychological toll, sometimes leading to autistic burnout. The stress from years of mismatch between expectations and abilities, without adequate support, can lead to chronic exhaustion, skill loss, and reduced tolerance for everyday stimuli.
Cat Patterson, a woman diagnosed with autism at age 63, writes: “Autistic people tend to burn out from our constant efforts to get along in this world. We burn out before we realise what is happening, and it’s too late to pull back.”
Researchers have found that Autistic adults and children are more susceptible to post-traumatic stress disorder (PTSD). And for them, an accumulation of smaller, persistent traumas, not only single severe events, may make their PTSD symptoms worse.
Complex Post-Traumatic Stress Disorder (C-PTSD)
This slow-burn path to mental health crisis is known as complex PTSD (C-PTSD) and can affect anyone. While C-PTSD is not listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM), the World Health Organization (WHO) recognized it in 2019. The WHO defines it as a result of severe and prolonged conditions, such as domestic violence, torture, or childhood abuse—from which escape is “impossible or extremely difficult.” But, as we will learn, the Autistic brain has a different barometer for what is processed as traumatic.
C-PTSD and Autism: What’s the Connection?
What researchers have not probed is a possible link between these two phenomena: Can the cumulative trauma of living with undiagnosed ASD lead to or increase the risk of developing PTSD or C-PTSD? Accounts from individuals with late-diagnosed ASD and observations from mental health professionals indicate that such a link exists, which makes a strong case for studying this possibility scientifically.
The Constant Strain of Masking
It seems all Autistic people may objectively experience more stressor events than their allistic (non-autistic) peers, such as bullying, rejection, sensory overload, stigma, or discrimination. And many individuals seek to avoid these perils through masking, or suppressing natural behaviors. But no one can will themselves to be different, and trying to leads to further stress.
Bowen Tyler Marshall, PhD is a licensed counselor and neurodivergence thought leader who identifies as AuDHD (Autistic + ADHD) and works primarily with cognitively neurodivergent clients (those who are ADHD, AuDHD, or Autistic). He put it this way: “ADHD and Autism are baked into how our brains are shaped and configured, how we sense the world, and the number and types of cells and neurotransmitters we have. There is no ‘me’ apart from my ADHD or Autism spectrum traits.”
A More Sensitive Threat Response
The stress of masking and fear of adverse social experiences may be two reasons why Autistic brains actually process the environment (school, work, grocery store) with extra vigilance. In fact, at baseline, it’s similar to the way a neurotypical brain with PTSD might respond, with a lower threshold for what is interpreted as threatening. And this is one reason why most providers with expertise in ASD agree that autism is a risk factor for developing C-PTSD.
While the DSM-5 defines trauma as witnessing or experiencing threat of or actual death, serious injury, or sexual violence, there’s evidence that Autistic people can experience trauma from challenges others might brush off, such as those stressors listed above.
In other words, a great deal of autistic PTSD may be getting overlooked, both clinically and personally.
Other Trauma-in-Autism Mechanisms
Masking and threat-sensitive neurobiology are well established mechanisms that help us understand the link between autism and trauma. Other hypotheses offer us additional mechanisms to consider:
- Shared etiology: Some researchers suggest there are underlying conditions that contribute to both autism and PTSD. It may not be that one causes the other, but that they tend to coexist due to shared mechanisms.
- Appraisal process: Autistic people may face greater barriers to healthy post-traumatic appraisal, potentially due to a lifetime of stigma and victimization, which may contribute to more severe PTSD symptoms.
- Directness of impact: Autistic people are more likely to report traumatic events as having happened to them directly, rather than as witnesses or bystanders.
- Vulnerability: The reasons for this are not understood, but Autistic people may simply experience more objectively traumatizing events. Autistic women report nearly twice as many incidents of sexual violence than allistic women; and 72% of Autistic adults in a 2021 survey reported sexual assault, unwanted sexual experiences, or physical assault.
The Extra Pain of Late Diagnosis
Being Autistic presents plenty of challenges in a world built for neurotypical brains. But it can be even harder for those who don’t know they’re Autistic.
People diagnosed later in life describe having felt perplexed about why they never seemed to fit in, why they’ve always felt to blame for things going wrong. There are also signs that the longer people live with undiagnosed autism, the stronger their autistic traits, likely due to burnout. In any case, the evidence is clear: Late-diagnosed adults have far higher rates of mental health conditions.
Most late-diagnosis research doesn’t mention trauma specifically, but a small study on age of diagnosis and quality of life does acknowledge, “adults receiving late diagnoses of autism will be dealing with the residuals of years of trauma, of years of being misunderstood, criticized and bullied without knowing why.”
Despite almost no presence in the research, in the real world, late-diagnosed Autistic people are being subsequently diagnosed with C-PTSD. Patterson writes, “I endured pain and trauma through my whole life and found social contact confusing and exhausting.”
Listen to Autistic Voices
While research looking at a connection between late autism diagnosis and PTSD is virtually nonexistent, Autistic people are telling us what they’re experiencing. Furthermore, many mental health providers see this and agree. It’s unclear from a scientific perspective what the mechanism is, but anecdotally, it seems that a late-diagnosis-trauma state exists above and beyond what we see in earlier-diagnosed Autistic people.
Learn More About Autism-Informed Mental Health Care
If you are Autistic and carrying trauma, or wondering whether years of being misunderstood, overwhelmed, or forced to mask have affected your mental health, CooperRiis can help. We treat PTSD and trauma-related symptoms through autism-informed care that begins with listening to your lived experience and understanding your desires for the future. You do not need to separate your Autism from your trauma to be understood here.
Programs ranging from 30 days to 6 months are available to support adults with a wide range of mental health needs.