The ages of anxiety--differences across the lifespan in the default mode network functional connectivity in generalized anxiety disorder

Abstract

Objectives: Generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders, but its neural basis is relatively understudied. This study aims to characterize the functional connectivity in the default mode network (DMN) in GAD across the lifespan.

Design and settings: Functional and structural magnetic resonance imaging data were collected with subjects at rest. We analyzed the resting state functional connectivity patterns in the DMN for 27 GAD participants and 39 non-anxious comparison participants. Using a two-way analysis of variance, we explored the interaction between age and GAD status on functional connectivity. In GAD participants, we analyzed the correlation of functional connectivity indices with the duration of illness and worry severity.

Results: The age-by-anxiety interaction showed a greater anxiety effect on the functional connectivity between the posterior cingulate seed and the medial prefrontal cortex for the older group relative to the younger participants. Longer duration of illness was positively correlated with greater functional connectivity between the posterior cingulate cortex and the insula. Worry severity was inversely correlated with the functional connectivity between the posterior cingulate cortex seed and the medial prefrontal cortex.

Conclusion: The presence of GAD, longer duration of illness, and more severe worry exacerbate the effects of age on the functional connectivity in the DMN. These results support the need for tailored research and interventions in late-life anxiety.

Keywords: age effect; duration of illness; functional connectivity; generalized anxiety disorder; resting state; worry severity.