Association of Amygdala Development With Different Forms of Anxiety in Autism Spectrum Disorder.

This study followed autistic children's brain development for about 8 years using brain scans. Researchers found that autistic children with typical anxiety disorders (like social anxiety) had larger brain areas responsible for fear and emotion processing. However, autistic children with autism-specific anxieties (like fear of change) showed slower growth in these same brain areas. This suggests these two types of anxiety in autism may work differently in the brain and might need different support approaches.

This longitudinal neuroimaging study examined amygdala development in 71 autistic and 55 typically developing children over approximately 8 years (ages 2.5-12). Researchers distinguished between traditional DSM anxiety disorders and autism-specific anxieties using specialized diagnostic interviews. Results revealed distinct amygdala development patterns: autistic children with DSM anxiety showed consistently larger right amygdala volumes (5-6% increase) compared to typically developing children at both early and later timepoints. Conversely, autistic children with autism-distinct anxieties demonstrated slower right amygdala growth and smaller volumes at the final timepoint compared to other autism groups.

These differential neurobiological trajectories suggest that DSM anxiety and autism-specific anxieties may have distinct underlying mechanisms in autism.

Results suggest DSM anxiety and autism-specific anxieties may require different therapeutic approaches due to distinct neurobiological profiles. Clinicians should carefully differentiate between anxiety types when assessing autistic individuals. Brain imaging patterns may eventually inform personalized treatment selection, though further validation is needed.

Single neuroimaging study with modest sample size. Anxiety assessments only conducted at final timepoint rather than longitudinally. Limited to amygdala volume measures without functional connectivity data. Findings require replication in larger, independent samples before clinical translation.

The amygdala is widely implicated in both anxiety and autism spectrum disorder. However, no studies have investigated the relationship between co-occurring anxiety and longitudinal amygdala development in autism. Here, the authors characterize amygdala development across childhood in autistic children with and without traditional DSM forms of anxiety and anxieties distinctly related to autism. Longitudinal magnetic resonance imaging scans were acquired at up to four time points for 71 autistic and 55 typically developing (TD) children (∼2.5-12 years, 411 time points).

Traditional DSM anxiety and anxieties distinctly related to autism were assessed at study time 4 (∼8-12 years) using a diagnostic interview tailored to autism: the Anxiety Disorders Interview Schedule-IV with the Autism Spectrum Addendum. Mixed-effects models were used to test group differences at study time 1 (3.18 years) and time 4 (11.36 years) and developmental differences (age-by-group interactions) in right and left amygdala volume between autistic children with and without DSM or autism-distinct anxieties and TD children. Autistic children with DSM anxiety had significantly larger right amygdala volumes than TD children at both study time 1 (5.10% increase) and time 4 (6.11% increase). Autistic children with autism-distinct anxieties had significantly slower right amygdala growth than TD, autism-no anxiety, and autism-DSM anxiety groups and smaller right amygdala volumes at time 4 than the autism-no anxiety (-8.13% decrease) and autism-DSM anxiety (-12.05% decrease) groups.

Disparate amygdala volumes and developmental trajectories between DSM and autism-distinct forms of anxiety suggest different biological underpinnings for these common, co-occurring conditions in autism.