Structural evidence for involvement of a left amygdala-orbitofrontal network in subclinical anxiety

Abstract

Functional neuroimaging implicates hyperactivity of amygdala-orbitofrontal circuitry as a common neurobiological mechanism underlying the development of anxiety. Less is known about anxiety-related structural differences in this network. In this study, a sample of healthy adults with no history of anxiety disorders completed a 3T MRI scan and self-report mood inventories. Post-processing quantitative MRI image analysis included segmentation and volume estimation of subcortical structures, which were regressed on anxiety inventory scores, with depression scores used to establish discrimant validity. We then used a quantitative vertex-based post-processing method to correlate (1) anxiety scores and (2) left amygdala volumes with cortical thickness across the whole cortical mantle. Left amygdala volumes predicted anxiety, with decreased amygdala volume associated with higher anxiety on both state and trait anxiety measures. A negative correlation between left amygdala volume and cortical thickness overlapped with a positive correlation between anxiety and cortical thickness in left lateral orbitofrontal cortex. These results suggest a structural anxiety network that corresponds with a large body of evidence from functional neuroimaging. Such findings raise the possibility that structural abnormalities may result in a greater vulnerability to anxiety or conversely that elevated anxiety symptoms may result in focal structural changes.

Neurocognitive Correlates of Apathy and Anxiety in Parkinson's Disease

“…In RPD, by contrast, anxiety but not apathy significantly correlated with performance on verbally mediated tasks. This finding provides additional support to lesion studies and neuroimaging reports relating anxiety to left-hemisphere dysfunction [59–61, 63, 65]. Taken together, our results demonstrated a differential association of apathy and anxiety with cognition in PD.…”

Depression and Anxiety Scores Are Associated with Amygdala Volume in Cushing’s Syndrome: Preliminary Study

“…These findings are in line with other populations, where left amygdala volumes have been negatively correlated with both state and trait anxiety levels in normal population and with anxiety state in panic disorder [46, 47]. In fact, in emotion studies, a lateralization to the left in amygdala activation has been reported, particularly for negative emotions, which may play a role in our results [48].…”

Prefrontal Limbic-Striatal Circuits and Alcohol Addiction in Humans

“…This result is consistent with a previous report that an intravenous injection of alcohol decreases limbic brain response to fearful faces in healthy individuals (Gilman et al, 2008). Given the critical role of the amygdala and OFC in modulation of anxiety and aversive emotion (Blackmon et al, 2011;Grachev & Apkarian, 2000;Urry et al, 2006), these results support the well-known effects of alcohol in its ability to reduce anxious and negative emotion via reduction in amygdala activity or amygdala-OFC connectivity in response to aversive emotions in healthy individuals.…”