Anorexia nervosa (AN) is a psychiatric disorder that is defined by maintenance of low weight by altering eating behaviors to avoid weight gain. Anxiety symptoms are frequently comorbid with AN psychopathology. Regions of the brain, including the amygdala, hippocampus, thalamus, orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC) were previously implicated in both AN and anxiety. The purpose of this study was to determine the relationship between AN and anxiety in these regions.
Neuroimaging data were obtained from 57 female participants with AN and 28 healthy controls (HCs). Statistical measures demonstrated that there were significant reductions in volume in the right amygdala, the bilateral thalamus, and the bilateral OFC in AN. Trait anxiety was also found to be significantly higher in participants with AN than HCs, yet was not associated with areas where volume reduction was observed.
This study indicates that AN psychopathology is more likely to underlie the structural brain changes that we observe as opposed to trait anxiety. In healthy females, higher trait anxiety is related to lower ACC volume, but this relationship is absent in participants with AN. Future studies are needed to further explore a relationship between AN and trait anxiety.
Anorexia nervosa (AN) is a psychiatric disorder characterized by low weight, with anxiety symptoms frequently comorbid. Prior studies have implicated brain regions of interest (ROI) in the pathophysiology of AN and anxiety, including the amygdala, hippocampus, thalamus, orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC). This study aims to understand the neurobiological correlates of anxiety symptoms in the context of AN.
MRI data from 57 female participants with AN and 28 healthy controls (HCs) were acquired and processed with bilateral volumes of each ROI extracted via FreeSurfer. ANCOVAs revealed significantly lower volume (p<0.005) in the right amygdala, left ACC, and thalamus and OFC bilaterally in AN. A Two-Sample t-test demonstrated higher STAI scores in patients with AN. Yet, ROI volumes were not correlated with STAI scores in participants with AN. A corrected trend level (p=0.008) correlation between STAI scores and the volume of the left ACC was present in HCs.
Results included reduced volumes in key regions implicated in AN and more severe anxiety symptoms in AN vs. HC. The lack of relationship between structural alterations and trait anxiety symptoms in AN suggests that observed brain changes may be more associated to AN pathophysiology than trait anxiety.