Intrinsic functional connectivity of amygdala-based networks in adolescent generalized anxiety disorder.

Objective: Generalized anxiety disorder (GAD) typically begins during adolescence and can persist into adulthood. The pathophysiological mechanisms underlying this disorder remain unclear. Recent evidence from resting state functional magnetic resonance imaging (R-fMRI) studies in adults suggests disruptions in amygdala-based circuitry; the present study examines this issue in adolescents with GAD.
Method: Resting state fMRI scans were obtained from 15 adolescents with GAD and 20 adolescents without anxiety who were group matched on age, sex, scanner, and intelligence. Functional connectivity of the centromedial, basolateral, and superficial amygdala subdivisions was compared between groups. We also assessed the relationship between amygdala network dysfunction and anxiety severity.
Results: Adolescents with GAD exhibited disruptions in amygdala-based intrinsic functional connectivity networks that included regions in medial prefrontal cortex, insula, and cerebellum. Positive correlations between anxiety severity scores and amygdala functional connectivity with insula and superior temporal gyrus were also observed within the GAD group. There was some evidence of greater overlap (less differentiation of connectivity patterns) of the right basolateral and centromedial amygdala networks in the adolescents with, relative to those without, GAD.
Conclusions: These findings suggest that adolescents with GAD manifest alterations in amygdala circuits involved in emotion processing, similar to findings in adults. In addition, disruptions were observed in amygdala-based networks involved in fear processing and the coding of interoceptive states.
(Copyright © 2013 American Academy of Child and Adolescent Psychiatry. All rights reserved.)