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Dopaminergic mechanisms underlying normal variation in trait anxiety: supplemental

Citation

Berry, Anne; Berry, Anne (2018), Dopaminergic mechanisms underlying normal variation in trait anxiety: supplemental , UC Berkeley Dash, Dataset, https://doi.org/10.6078/D1JM3K

Abstract

Trait anxiety has been associated with altered activity within corticolimbic pathways connecting the amygdala and rostral anterior cingulate cortex (rACC), which receive rich dopaminergic input. Though the popular culture uses the term “chemical imbalance” to describe the pathophysiology of psychiatric conditions such as anxiety disorders, we know little about how individual differences in dopamine neurochemistry are related to variation in anxiety and activity within corticolimbic circuits. We addressed this issue by examining inter-individual variability in dopamine release at rest using [11C]raclopride PET, functional connectivity between amygdala and rACC using resting-state fMRI, and trait anxiety measures in healthy adult humans. We found a negative relationship between dopamine release and trait anxiety such that individuals with higher dopamine release in the amygdala and rACC self-reported lower trait anxiety. Lower trait anxiety was also associated with reduced rACC-amygdala functional connectivity at baseline. Further, functional connectivity showed a modest negative relationship with dopamine release such that individuals with reduced rACC-amygdala functional connectivity showed higher levels of dopamine release in these regions. Together, these findings contribute to hypodopaminergic models of anxiety and support the utility of combining fMRI and PET measures of neurochemical function to advance our understanding of basic affective processes in humans.

Methods

Supplemental materials are provided here, which include analyses of dopamine release in striatum and relationships with trait anxiety. Additionally, we include analysis of right vs left hemisphere dopamine release and funcitonal connectivity for amygdala and rostral anterior cingulate cortex. 

Funding

National Institute of Health, Award: R01 DA034685; R01 AG044292