A unique neural and behavioral profile of social anxiety in autism

TL;DR

This study finds that autistic adults with social anxiety show unique behaviors and brain features, particularly involving the amygdala.

Contribution

The study identifies a unique neural and behavioral profile of social anxiety in autism, particularly involving the amygdala.

Findings

Individuals with both social anxiety and autism show acquiescent behaviors compared to those with autism or social anxiety alone.

The amygdala is uniquely enlarged in autistic adults with social anxiety and linked to difficulties in power dynamics.

Larger amygdala volume is associated with more pronounced acquiescent behaviors in autism when social anxiety is present.

Abstract

Social anxiety (SA) commonly co-occurs with autism spectrum disorder (ASD), each sometimes misdiagnosed as the other. We examine behavioral and neural profile of SA in ASD in an online study (ASD = 575, control = 357) and a neuroimaging study (ASD = 72, control = 72). Using a naturalistic social interaction task, we identified acquiescent behaviors in individuals with both SA and ASD compared to those with ASD or SA alone. The amygdala—previously linked to anxiety and ASD—was uniquely enlarged only in adults with both SA and ASD. Furthermore, larger amygdala volume was associated with acquiescent behaviors in ASD, a relationship that was enhanced when accounting for SA. These findings suggest that autistic adults with larger amygdala are more likely to experience SA and difficulties in power dynamics (dominance or control), highlighting unique phenotype of SA in ASD.

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