Study explores how changing autism traits are linked to mental health conditions

A long-term study by UC Davis Health researchers sheds new light on the relationship between autism traits and mental health in middle childhood. The paper, published in the journal Autism, finds that changes in core autism characteristics are related to whether children develop additional mental health challenges during their elementary school years.

"Our findings suggest that different aspects of a child's development may affect each other over time," explained Einat Waizbard-Bartov, a doctoral researcher in developmental psychology at the UC Davis MIND Institute and the lead author on the paper. "Core autism traits and mental health challenges likely interact throughout development."

A key finding was that a reduction in restrictive and repetitive behaviors during elementary school was linked to the emergence of mental health challenges, lending support to the idea that these behaviors may benefit autistic individuals. An increase in social-communication difficulties during this time was also linked to anxiety and other mental health challenges.

Study design

Waizbard-Bartov has published previous research showing autism characteristics can change significantly from ages 3 to 11.

The current study included 75 autistic children ages 6 to 11, including 15 girls. All were part of the MIND Institute's Autism Phenome Project, a large, long-term study aimed at identifying different subtypes of autism.

Through parental interviews and questionnaires, the research team evaluated the children for mental health symptoms and restricted and repetitive behaviors, which can include seeking sensory stimulation, hand-flapping or sticking to set routines.

They tracked changes in autism characteristics using the Autism Diagnostic Observation Schedule Calibrated Severity Score.

About a fifth (21%) of the youth had more severe social-communication difficulties, as well as an increase in anxiety, ADHD and behavioral challenges. In contrast, nearly 23% had decreased restricted and repetitive behaviors but higher anxiety levels by age 11. Nearly all—94% —met the criteria for an anxiety disorder.

About a third of the participants had both decreasing restricted and repetitive behaviors and increased social-communication difficulties.

"We were pleased to see that our results confirmed what has been suspected by other autism researchers and clinicians as well as autistic individuals, that some forms of restricted and repetitive behaviors can potentially help to self-soothe," said David Amaral, distinguished professor in the Department of Psychiatry and Behavioral Sciences, MIND Institute faculty member and senior author on the paper.

Waizbard-Bartov notes that the findings question the wisdom of therapies that try to eliminate these behaviors.

"In light of this, when thinking about interventions, it might be that trying to eliminate repetitive behaviors without providing alternative self-soothing tools is not the ideal way to go," she said.

The study is the first, to the authors' knowledge, to demonstrate an association between mental health challenges and increases in the severity of social-communication difficulties for autistic children.

"This occurred in children who showed decreases in core autism traits during early childhood and whose cognitive functioning was in the typical range. We don't currently understand why this happened. One possibility is that due to their relatively high cognitive ability, they became aware of their social challenges, and this may have contributed to increasing anxiety," Amaral explained. "It's definitely an area where we need more research."