Association of adverse childhood experiences and precuneus volume with intrusive reexperiencing in autism spectrum disorder.
More childhood trauma in adults with autism is tied to a smaller right precuneus and more upsetting flashbacks.
01Research in Context
What this study did
Kitamura et al. (2021) scanned the brains of adults with autism and typical adults. They asked everyone how many bad childhood events they had lived through. Then they measured the size of a brain spot called the right precuneus.
The team also asked how often each person had sudden, upsetting flashbacks. They wanted to see if more childhood trauma links to a smaller precuneus and more flashbacks in autism.
What they found
Adults with autism who had worse childhood trauma also had a smaller right precuneus. The same adults reported stronger intrusive reexperiencing, like vivid memories that pop up without warning.
The typical adults did not show these links as clearly. The results point to a brain mark of early stress that may feed trauma-like symptoms in autism.
How this fits with other research
Rigles (2017) first showed that autistic children rack up more adverse events than peers, and these events hurt their health. Soichiro moves that story forward by showing the hurt may leave a visible brain trace in adulthood.
Andrzejewski et al. (2023) add another layer: trauma travels from caregiver to child. Their survey of youth-caregiver pairs found both members report high ACE counts, hinting that family-wide screening is needed.
Jackson et al. (2025) and Hartwell et al. (2024) look at school life. Each extra ACE predicts worse attendance, lower grades, and fewer special-ed minutes for autistic students. Together with Soichiro’s brain data, the picture is clear: early adversity hits autistic people at every level—from brain size to report-card grades.
Why it matters
You can’t scan a client’s brain in clinic, but you can ask about childhood trauma. If the answer is high, expect stronger anxiety, flashbacks, and possible learning blocks. Fold trauma-informed tactics into your behavior plans: give choices, warn before transitions, and teach coping scripts. Also push for school teams to keep services robust—Micah showed high-ACE kids often lose supports that help them stay on track.
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02At a glance
03Original abstract
Compared to typically developing (TD) children, people with autism spectrum disorder (ASD) have an increased risk of adverse childhood experiences (ACEs). Exposure to ACEs is associated with adult ASD psychological comorbidities, such as posttraumatic stress disorder (PTSD). Occurrence of intrusive event reexperiencing, characteristic of PTSD, often causes social dysfunction in adults with ASD, but its pathological basis is unclear. This study examined brain regions related to the severity of intrusive reexperiencing and explored whether ACE severity was associated with that of intrusive reexperiencing and/or extracted regional gray matter volume. Forty-six individuals with ASD and 41 TD subjects underwent T1-weighted magnetic resonance imaging and evaluation of ACEs and intrusive reexperiencing. Brain regions related to the severity of intrusive reexperiencing in both groups were identified by voxel-based whole brain analyses. Associations among the severity of intrusive reexperiencing, that of ACEs, and gray matter volume were examined in both groups. The severities of intrusive reexperiencing and ACEs were significantly associated with reduced gray matter volume in the right precuneus in individuals with ASD but not in TD subjects. Although the right precuneus gray matter volume was smaller in individuals with ASD and severe ACEs than in those with mild ACEs or TD subjects, it was similar in the latter two groups. However, ACE-dependent gray matter volume reduction in the right precuneus led to intrusive reexperiencing in individuals with ASD. This suggests that exposure to ACEs is associated with right precuneus gray matter reduction, which is critical for intrusive reexperiencing in adults with ASD. LAY SUMMARY: Individuals with autism spectrum disorder (ASD) are at increased risk of adverse childhood experiences (ACEs) and of subsequent manifestation of intrusive reexperiencing of stressful life events. The present study found that reduced gray matter volume in the right precuneus of the brain was associated with more severe intrusive reexperiencing of ACEs by individuals with ASD. These results suggest that ACEs affect neural development in the precuneus, which is the pathological basis of intrusive event reexperiencing in ASD.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2558