A smaller amygdala is associated with anxiety in Parkinson’s disease: a combined FreeSurfer—VBM study

These results confirm studies in non-PD samples showing lower left amygdalar volume in anxious patients. The results also indicate that the 'psychological' BAI subscale is a better reflection of neural correlates of anxiety in PD. Whether the left amygdalar volume decrease constitutes a premorbid trait, a PD-associated neurobiological susceptibility to anxiety or arises as a consequence of chronic anxiety symptoms remains to be determined by future prospective longitudinal studies. Nonetheless, we speculate that the Parkinson pathology is responsible for the reduction in amygdalar volume and the concomitant development of anxiety symptoms.