UC Berkeley Dash
Citation (2018), Dataset, https://doi.org/10.6078/D1JM3K
Berry, Anne
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.