Amygdalar volumetric correlates of social anxiety in offspring of parents with bipolar disorder

The prevalence of social anxiety disorder is high in offspring of parents with bipolar disorder (BD) and anxiety may be a significant risk factor in these youth for developing BD. We compared social anxiety symptoms between BD offspring with mood symptoms (high-risk group for developing BD I or II: HR) and healthy controls (HC). We also explored the correlations between the amygdalar volumes and social anxiety symptoms in the HR group with high social anxiety scores (HRHSA) due to the potential involvement of the amygdala in the pathophysiology of both BD and social anxiety. Youth participating in the study included 29 h and 17 HC of comparable age and gender. To assess social anxiety symptoms, we used the Multidimensional Anxiety Scale for Children (MASC) social anxiety subscale. The HR group's MASC social anxiety score was significantly higher than that of the HC group. Among the 29 h, 17 subjects (58.6%) showed high social anxiety and they were classified as the HRHSA group. No significant difference was observed in amygdalar volume between the HRHSA and HC groups. However, there were significant negative correlations between amydalar volumes and MASC social anxiety score in the HRHSA group. These findings have implications for the link between amygdalar structure and both anxiety and mood control. This link may serve to implicate high social anxiety as a risk marker for future BD development.