Guest post by neurobiologist Pat Levitt, Ph.D., of the University of Southern California’s Keck School of Medicine, in Los Angeles
Many children with autism spectrum disorders (ASD) have co-occurring medical conditions that affect their quality of life and response to therapy. One of the most common of these medical conditions is gastrointestinal (GI) disorder. Our research directly examines the relationship between the two and creates a foundation for understanding the biology and behaviors unique to children affected by both disorders. It is described, in detail, in our recent report in the journal Autism Research.
Our multi-disciplinary research group included neuroscientists, a clinical psychologist, a pediatrician and a pediatric gastroenterologist. We enrolled 121 children through Vanderbilt University, in Nashville, primarily through Vanderbilt’s autism clinic, which is part of the Autism Speaks Autism Treatment Network (ATN). These children fell into one of three groups: those with ASD and GI disorder, those with ASD only and those with GI disorder only. Their parents completed a dietary journal and questionnaires about the children’s behavior and GI symptoms. In addition, a pediatric gastroenterologist evaluated the children with GI disorders.
We found very high agreement - more than 90 percent - between parent reports of GI symptoms and the gastroenterologist’s evaluations. While the specific description of the GI condition sometimes varied between parent and physician, these findings suggest that contrary to what some people think, parents do not over-report GI conditions in their children. Also contrary to some popular thought, the children’s diet and medications did not significantly contribute to their GI distress.
Overall constipation was the most common GI diagnosis. It occurred in 85 percent of children with both autism and GI disorder and was most likely to occur in children who were younger, nonverbal and/or had significant social difficulties. In fact, we found a six-fold increase in communication disturbances in the group of children who had both ASD and GI disorder, compared to children with ASD only.
This strong association between constipation and language impairment has the support of a previous study showing a unique genetic association between children with ASD and GI disorder. As such, our findings further highlight the need for healthcare providers to be vigilant in detecting and treating GI symptoms in children on the spectrum. This is particularly important in the care of nonverbal children who can’t describe their distress. Our research also provides a strong foundation for further research on the causes and treatment of autism associated with GI disorder. We need to know more about how these co-occurring conditions affect the mental and physical health of so many children and adults.
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