Dorsolateral prefrontal cortical pathology in generalized anxiety disorder: a proton magnetic resonance spectroscopic imaging study.

OBJECTIVE Few neuroimaging studies of generalized anxiety disorder have been conducted. The present study used proton magnetic resonance spectroscopy to assess concentrations of N-acetylaspartate, often considered a marker of neuronal viability, in generalized anxiety disorder patients. METHOD N-Acetylaspartate/creatine resonance ratios were measured in the left and right dorsolateral prefrontal cortex and hippocampus of 15 medication-free generalized anxiety disorder patients and 15 age- and sex-matched healthy volunteers. RESULTS Generalized anxiety disorder patients had a 16.5% higher N-acetylaspartate/creatine ratio in the right dorsolateral prefrontal cortex compared with healthy participants; 13 of 15 matched patient-comparison subject pairs displayed a difference in this direction. In addition, generalized anxiety disorder patients reporting childhood abuse had lower N-acetylaspartate/creatine ratios in the right dorsolateral prefrontal cortex than did nonabused patients. Metabolite differences were not detected in other regions. CONCLUSIONS Generalized anxiety disorder is associated with asymmetric increases in the N-acetylaspartate/creatine ratio, a suggested marker of neuronal viability, in the prefrontal cortex. The findings also support prior research linking childhood abuse to reduced neuronal viability.