A Pilot Study of Anterior Cingulate Cortex Neurochemistry in Adolescents with Generalized Anxiety Disorder

Abstract

Background/Aims: This study used proton magnetic resonance spectroscopy (¹H MRS) to evaluate the neurochemistry of the anterior cingulate cortex (ACC) in adolescents with generalized anxiety disorder (GAD). Methods: Adolescents with GAD (n = 10) and healthy subjects (n = 10) underwent a ¹H MRS scan at 4 T. Glutamate (Glu), N-acetyl aspartate, creatine (Cr) and myo-inositol concentrations were measured in the ACC and were compared between untreated adolescents with GAD and age- and sex-matched healthy subjects. Results: Glu/Cr ratios in the ACC correlated with the severity of both generalized anxiety symptoms on the Pediatric Anxiety Rating Scale and with total anxiety symptom severity as measured by the Hamilton Anxiety Rating Scale, but did not differ between adolescents with GAD and healthy subjects. In addition, no differences in N-acetyl aspartate, Cr, or myo-inositol were detected between groups. Conclusion: These findings suggest that Glu/Cr in untreated adolescents with GAD may relate to the severity of anxiety symptoms and raise the possibility that dysregulation of Glu within the ACC may be linked to the pathophysiology of pediatric GAD.

Metabolic alterations in generalised anxiety disorder: a review of proton magnetic resonance spectroscopic studies

“…Moreover, an inverse correlation was observed between hippocampal NAA and body mass index as well as higher worry predicted low hippocampal NAA and PCr + Cr. Lastly, Strawn et al (2013) recently reported no significant alterations in glutamate/PCr + Cr ratios in the anterior cingulate of adolescents with GAD; however, a positive correlations between glutamate/PCr + Cr and anxiety symptoms severity.…”

“…Briefly, among the 11 studies retrieved, the majority employed a multi-voxel (N = 7) instead of a single-voxel (N = 4) ¹H MRS technique and a 1.5 T scanner (N = 6) instead of a 3 T (N = 4) or a 4 T (N = 1) scanner. Interestingly, all the ¹H MRS studies on GAD, except for two studies Abdallah et al 2012a;Strawn et al 2013), focused on brain regions within the hippocampus and dorsolateral prefrontal cortex (DLPFC).…”

Working memory dysfunction associated with brain functional deficits and cellular metabolic changes in patients with generalized anxiety disorder

“…Therefore, it is assumed that both brain functional deficits and cellular metabolic alterations might be associated with GAD symptoms. However, the nature of the causality between functional and metabolic brain alterations is unclear, since brain functional or neurochemical studies (Blair et al, 2008;Mathew et al, 2008;Monk et al, 2008;McClure et al, 2011;Price et al, 2011;Ball et al, 2013;Strawn et al, 2013) have been separately performed. A combined fMRI and 1 H-MRS study would be valuable to investigate whether the brain functional abnormality is associated with the metabolic changes in connection with emotional dysregulation and cognitive deficit in patients with GAD.…”

Quantifying absolute glutamate concentrations in nucleus accumbens of prescription opioid addicts by using 1H MRS

“…Several studies have demonstrated that glutamate is increased in the ACC in patients with general anxiety disorder (Strawn et al, 2013) or social anxiety disorder (Pollack, Jensen, Simon, Kaufman, & Renshaw, 2008). Excess glutamate in anxiety is not only found in categorical comparisons, but also correlates with anxiety severity.…”