A repeat proton magnetic resonance spectroscopy study in social phobia

Abstract

Peak spectral amplitudes for choline moieties (Cho), creatine (Cr), N-acetylaspartate (NAA), and myo-inositol (mI) were examined using proton magnetic resonance spectroscopy in 19 social-phobia patients and 10 controls. Compared with controls, social phobics demonstrated significantly lower NAA/Cho and higher Cho/Cr, mI/Cr, and mI/NAA amplitudes in cortical gray matter. Higher mI/Cr and mI/NAA amplitudes for social phobics were also observed in subcortical gray matter. Minimal between-group differences were noted for white matter. Symptom severity correlated inversely with amplitudes primarily in subcortical gray matter, and to a lesser extent in cortical gray matter. Inclusion of age and sex in statistical modeling strengthened comparisons with controls but eliminated those for symptom severity. No changes were observed in any amplitude measure following at least 8 weeks of clonazepam treatment, nor was a relationship observed between amplitudes and cumulative clonazepam dose. The possible psychobiological implications of our findings in social phobia are discussed.