A repeat proton magnetic resonance spectroscopy study in social phobia

Area of Science:

• Neuroscience
• Psychiatry
• Biochemistry

Background:

• Social phobia is a prevalent anxiety disorder with unclear neurobiological underpinnings.
• Proton magnetic resonance spectroscopy (MRS) allows in vivo measurement of brain metabolites.

Purpose of the Study:

• To investigate differences in brain metabolite concentrations between individuals with social phobia and healthy controls.
• To explore the relationship between metabolite levels, symptom severity, and clonazepam treatment in social phobia.

Main Methods:

• Proton magnetic resonance spectroscopy (MRS) was used to measure peak spectral amplitudes of choline (Cho), creatine (Cr), N-acetylaspartate (NAA), and myo-inositol (mI).
• Measurements were taken in cortical gray matter, subcortical gray matter, and white matter of 19 social phobia patients and 10 controls.
• Correlations with symptom severity and effects of clonazepam treatment were analyzed.

Main Results:

• Social phobics exhibited significantly lower NAA/Cho and higher Cho/Cr, mI/Cr, and mI/NAA amplitudes in cortical gray matter compared to controls.
• Elevated mI/Cr and mI/NAA amplitudes were also found in the subcortical gray matter of social phobics.
• Symptom severity correlated inversely with metabolite amplitudes in gray matter regions. No significant changes were observed after clonazepam treatment.

Conclusions:

• Alterations in brain metabolite concentrations, particularly involving myo-inositol, are associated with social phobia.
• These neurochemical differences in gray matter may reflect underlying psychobiological mechanisms of the disorder.
• Clonazepam treatment did not appear to alter these measured metabolite levels in the studied cohort.