Background: The rostral prefrontal cortex (RPFC) is involved in reflective thought processes such as self-knowledge and person perception. We hypothesized that childhood emotional abuse, which is disruptive of emotional regulation, would differentially impact neurometabolite concentrations of the RPFC, and related neocortical areas, in adults with generalized anxiety disorder (GAD) versus healthy controls.
Methods: GAD patients (n=16; females=11) and medically healthy volunteers (n=16; F=10) were assessed using the Childhood Trauma Questionnaire (CTQ), specifically the emotional abuse category. Proton magnetic resonance spectroscopy imaging examined 3 regions of interest (ROI) from the most rostral slice from the Duyn et al. (1993) multivoxel imaging modality: rostral prefrontal cortex (BA 10,9), premotor cortex (BA 6,8) and secondary somatosensory and associated parietal cortex (BA 5,7). Metabolites included N-acetyl-aspartate, creatine, and choline.
Results: GAD patients reported higher emotional abuse scores versus controls. An omnibus general linear model including 3 ROI, 3 metabolites, and laterality as dependent variables revealed a significant diagnosis by CTQ emotional abuse score interactive effect. In controls, all 3 ROI for all 3 metabolites on both sides demonstrated a significant inverse relationship with emotional abuse scores; none were significant in GAD patients.
Limitations: A major limitation is the uneven distribution of emotional abuse scores between the controls and GAD patients, with GAD patients reporting higher scores.
Conclusion: Unlike controls, GAD patients appear compromised in forming a molecular representation reflective of magnitude of childhood emotional abuse. The neurometabolites in GAD patients appear non-aligned to childhood emotional abuse, suggesting potential consequences for normative "theory of mind" processes and emotional function in certain anxiety disorders.
Keywords: Choline (Cho); Emotional abuse; Generalized Anxiety Disorder (GAD); N-acetyl-aspartate (NAA); Neural networks; Rostral prefrontal cortex; “Theory of mind”.
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