Individuals with autism spectrum disorders (ASD) frequently suffer from gastrointestinal (GI) problems, and many also experience internalizing symptoms such as stress, anxiety, depression, and social withdrawal. A new study suggests that there is a bidirectional relationship between GI problems and internalizing symptoms in children and teens with autism—in other words, that the two problems are simultaneously impacting each other.

In the study, Kristen Dovgan and colleagues analyzed data collected from parental reports on 621 individuals with ASD, all of whom were under the age of 18 and suffered from gastrointestinal issues. The researchers say, “The best-fitting model was a bidirectional model wherein internalizing symptoms, including withdrawn and anxious behavior, were correlated with GI problems, including constipation, diarrhea, nausea, and stomach pain.” 

Study coauthor Bradley Ferguson says the findings emphasize the importance of the gut-brain axis in autism. He comments, “Research has shown gastrointestinal issues are associated with an increased stress response as well as aggression and irritability in some children with autism. This likely happens because some kids with autism are unable to verbally communicate their gastrointestinal discomfort as well as how they feel in general, which can be extremely frustrating.”

He adds, “Stress signals from the brain can alter the release of neurotransmitters like serotonin and norepinephrine in the gut, which control gastrointestinal motility, or the movement of stool through the intestines. Stress also impacts the balance of bacteria living in the gut, called the microbiota, which can alter gastrointestinal functioning. The gut then sends signals back to the brain, and that can, in turn, lead to feelings of anxiety, depression, and social withdrawal. The cycle then repeats, so novel treatments addressing signals from both the brain and the gut may provide the most benefit for some kids with gastrointestinal disorders and autism.”

“Bidirectional relationship between internalizing symptoms and gastrointestinal problems in youth with autism spectrum disorder,” Kristen Dovgan, Kyra Gynegrowski, and Bradley J. Ferguson, Journal of Autism and Developmental Disorders, April 20, 2022 (online). Address: Kristen Dovgan, Marist College, Department of Psychology, Poughkeepsie, NY 12601, [email protected] marist.edu.

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“Study finds a bidirectional link between gastrointestinal issues and internalized symptoms in kids with autism,” News-Medical.net, April 26, 2022.

This article originally appeared in Autism Research Review International, Vol. 36, No. 2, 2022