A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2022 | Number 1, Volume 36

Anxiety in children with ASD linked to differences in amygdala

Changes in the amygdala—an almond-shaped region in the brain—appear to be linked to the development of anxiety in children with autism spectrum disorders (ASD), according to a new study. 

Anxiety is one of the most common comorbidities in autism, with research indicating that 69 percent of children with ASD suffer from anxiety compared to only 8 percent of non-autistic children. Research indicates that dysregulation of the amygdala plays a role in anxiety, and that the growth trajectory of the amygdala is altered in many individuals with ASD. 

In the new study, Derek Sayre Andrews and colleagues used magnetic resonance imaging (MRI) to scan the brains of 71 children with ASD and 55 non-autistic controls as many as four different times when the children were between 2 and 12 years of age. The researchers also interviewed parents when the children were between 9 and 12 years of age to determine the children’s levels of traditional or autism-distinct anxiety. 

The researchers explain that the two types of anxiety are similar, but the latter involves anxiety arising within an autistic context. For instance, they say, autism-distinct anxiety may involve fears related to social confusion (as opposed to fear of negative evaluation), uncommon phobias (for instance, a fear of specific sounds or certain facial features), excessive worry related to losing access to materials related to circumscribed interests, or fears of change.

The researchers found that nearly half of the children with ASD exhibited traditional anxiety, autism-specific anxiety, or both. Those with traditional anxiety had significantly larger right amygdala volumes compared to controls, but the developmental trajectory of the amygdala was similar for both groups. In contrast, they say, children with autism-distinct anxiety “had slower development of the right amygdala from the ages of around 3 to 11 compared to typically developing and other autistic children, and smaller right amygdala volumes at around 11 years of age compared to other autistic children.” 

Study coauthor Christine Wu Nordahl says, “We were reminded that different autistic subgroups may have different underlying brain changes. If we had lumped both traditional and distinct anxieties together, the amygdala changes would have canceled each other out and we would not have detected these different patterns of amygdala development.” 

The researchers caution that their study sample was fairly small, and in particular contained few females with ASD. In addition, they note, their focus was limited to the amygdala, which has broad connections to many other brain regions whose role in anxiety in ASD needs to be explored.


Citations

“Association of amygdala development with different forms of anxiety in autism spectrum disorder,” Derek Sayre Andrews, Leon Aksman, Connor M. Kerns, Joshua K. Lee, Breanna M. Winder-Patel, Danielle Jenine Harvey, Einat Waizbard-Bartov, Brianna Heath, Marjorie Solomon, Sally J. Rogers, Andre Altmann, Christine Wu Nordahl, and David G. Amaral, Biological Psychiatry, February 2022 (online). Address: Derek Sayre Andrews,2825 50th St, Sacramento CA 95817, [email protected]

—and— 

“Amygdala changes in autistic individuals linked to anxiety,” news release, UC Davis, February 10, 202