A pilot study of gray matter volume changes associated with paroxetine treatment and response in social anxiety disorder

Psychiatry Res. 2015 Mar 30;231(3):279-85. doi: 10.1016/j.pscychresns.2015.01.008. Epub 2015 Jan 19.

Abstract

Social anxiety disorder (SAD) has received relatively little attention in neurobiological studies. We sought to identify neuro-anatomical changes associated with successful treatment for the disorder. Fourteen patients (31 years; 57% female) with DSM-IV generalized SAD were imaged before and after 8-weeks of paroxetine treatment on a 1.5 T GE Signa MRI scanner. Symptoms were assessed by a clinician using the Liebowitz Social Anxiety Scale (LSAS). Longitudinal changes in voxel based morphometry (VBM) were determined using the VBM8 Toolbox for SPM8. Symptom severity decreased by 46% following treatment (p<0.001). At week 8, significant gray matter reductions were detected in bilateral caudate and putamen, and right thalamus, and increases in the cerebellum. Gray matter decreases in left thalamus were correlated with clinical response. This is the first study to our knowledge to identify treatment related correlates of symptom improvement for SAD. Replication in larger samples with control groups is needed to confirm these findings, as well as to test their specificity and temporal stability.

Keywords: Caudate; Cerebellum; Paroxetine; Social anxiety; Structural MRI; Thalamus.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Gray Matter / anatomy & histology
  • Gray Matter / drug effects*
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Paroxetine / administration & dosage
  • Paroxetine / pharmacology*
  • Phobic Disorders / drug therapy*
  • Pilot Projects
  • Serotonin Uptake Inhibitors / administration & dosage
  • Serotonin Uptake Inhibitors / pharmacology*
  • Treatment Outcome

Substances

  • Serotonin Uptake Inhibitors
  • Paroxetine