Altered cortical thickness of the superior frontal gyrus and fusiform gyrus in individuals with subthreshold social anxiety.

Subthreshold social anxiety (SSA) is a condition in which individuals experience social anxiety that does not reach the threshold required for a clinical diagnosis of a social anxiety disorder (SAD). Although SSA may not impair lives as severely as SAD, it can affect social functioning. However, only a few studies focused on structural neural correlates of SSA. We recruited 65 individuals with SSA and used the Leibowitz Social Anxiety Scale to assess their social and performance anxiety levels and other relevant measures of social anxiety. Voxel-wise whole-brain correlational analyses showed a positive association between the cortical thickness (CT) of the superior frontal gyrus (SFG) and social anxiety levels and a negative correlation between the CT of the fusiform gyrus (FG) and performance anxiety levels in individuals with SSA. Exploratory Pearson's correlation analyses showed significant positive correlations between the CT of the SFG and Generalized Anxiety Disorder-7 total scores and negative associations between the CT of the FG and Beck Anxiety Inventory total scores. Our study provides insight into the neural basis of SSA, particularly performance anxiety, by highlighting the association between CT in specific brain regions and SSA characteristics.