title: (1)H-magnetic resonance spectroscopy in social anxiety disorder.
abstract: BACKGROUND
  Social anxiety disorder (SAD) is characterized by excessive anxiety about social interaction or performance situations, leading to avoidance and clinically significant distress. A growing literature on the neurobiology of SAD has suggested that the reward/avoidance basal ganglia circuitry in general and the glutamatergic system in particular may play a role. In the current study, we investigated (1)H-magnetic resonance spectroscopy ((1)H-MRS) concentrations in cortical, striatal, and thalamic circuitry, as well as their associations with measures of social anxiety and related symptoms, in patients with primary SAD.
  
  
  METHODS
  Eighteen adult individuals with SAD and 19 age- and sex- matched controls participated in this study. (1)H-MRS was used to determine relative metabolite concentrations in the anterior cingulate cortex (ACC) using single voxel spectroscopy (reporting relative N-acetyl-aspartate (NAA), N-acetyl-aspartate with N-acetyl-aspartyl-glutamate (NAA+NAAG), glycerophosphocholine with phosphocholine (GPC+PCh), myo-inositol, glutamate (Glu), and glutamate with its precursor glutamine (Glu+Gln)), and the caudate, putamen and thalami bilaterally using two dimensional chemical shift imaging (reporting relative NAA+NAAG and GPC+PCh). Relationships between metabolite concentrations and measures of social anxiety and related symptoms were also determined. Measures of social anxiety included symptom severity, blushing propensity, and gaze anxiety/avoidance.
  
  
  RESULTS
  We found, first, decreased relative glutamate concentration in the ACC of SAD and changes in myo-inositol with measures of social anxiety. Second, NAA metabolite concentration was increased in thalamus of SAD, and choline metabolite concentrations were related to measures of social anxiety. Lastly, choline metabolite concentration in the caudate and putamen showed changes in relation to measures of social anxiety.
  
  
  CONCLUSIONS
  These findings are consistent with evidence that the reward/avoidance basal ganglia circuitry, as well as the glutamatergic system, play a role in mediating SAD symptoms.
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, South Africa. Electronic address: howellsfleur@gmail.com.
authors.forename: Fleur M
authors.initials: FM
authors.lastname: Howells
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, South Africa.
authors.forename: Coenraad J
authors.initials: CJ
authors.lastname: Hattingh
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, South Africa; Department of Psychology, University of Toronto, Canada.
authors.forename: Supriya
authors.initials: S
authors.lastname: Syal
authors.affiliation: MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, University of Stellenbosch, South Africa.
authors.forename: Elsie
authors.initials: E
authors.lastname: Breet
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, South Africa; MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, University of Stellenbosch, South Africa.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
authors.affiliation: MRC Unit on Anxiety and Stress Disorders, Department of Psychiatry, University of Stellenbosch, South Africa.
authors.forename: Christine
authors.initials: C
authors.lastname: Lochner
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000378:metabolism*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004151:Dipeptides / Q000378:metabolism; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism*; D006801:Humans; D008297:Male; D017072:Neostriatum / Q000378:metabolism*; D010767:Phosphorylcholine / Q000378:metabolism; D066244:Proton Magnetic Resonance Spectroscopy; D011569:Psychiatric Status Rating Scales; D012938:Social Perception; D013788:Thalamus / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D010767:Phosphorylcholine; C027172:isospaglumic acid; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine
keywords: Anterior cingulate cortex (ACC); Glutamate; N-acetyl-aspartate (NAA); Striatum; Thalamus