The purpose of the study was to find grey matter (GM) and white matter (WM) volume reduction in the brain reward system among patients with alcohol dependency. This study investigated regional GM and WM in chronic alcoholic patients, focusing primarily on the reward system, including principal components of the mesocorticolimbic reward circuit as well as cortical areas with modulating and oversight functions. Sixteen abstinent long-term chronic alcoholic men and demographically matched 16 healthy control men participated in the study. Morphometric analysis was performed on magnetic resonance brain scans using voxel-based morphometry (VBM)-diffeomorphic Anatomical Registration through Exponentiated Liealgebra (DARTEL). We derived GM and WM volumes from total brain and cortical and subcortical reward-related structures. Morphometric analyses that revealed the total volume of GM and WM was reduced and cerebrospinal fluid (CSF) was increased in the alcohol group compared to control group. The pronounced volume reduction in the reward system was observed in the GM and WM of the nucleus accumbens (NAc), GM of the amygdala, GM and WM of the hippocampus, WM of the thalamus, GM and WM of the insula, GM of the dorsolateral prefrontal cortex (DLPFC), GM of the orbitofrontal cortex (OFC), GM of the cingulate cortex (CC), GM and WM of the parahippocampal gyrus in the alcohol group. We identified volume reductions in WM as well as GM of reward system in the patients with alcohol dependency. These structural deficits in the reward system elucidate underlying impairment in the emotional and cognitive processing in alcoholism.

1. Introduction
 2. Methods and Materials
  2.1. Subjects
  2.2. Magnetic Resonance Imaging (MRI) Acquisition
  2.3. Voxel-Based Morphometry (VBM) Analysis
  2.4. Region of Interest (ROIs) Analysis
 3. Results
  3.1. Whole Brain Analysis
  3.2. ROI Analysis in the Reward System
 4. Discussion
  4.1. DLPFC
  4.2. Thalamus
  4.3. Cingulate Cortex (CC)
  4.4. Hippocampus and Amygdala
  4.5. White Matter (WM)
 REFERENCES

• Jin-Hun Sohn(Department of Psychology, Brain Research Institute, Chungnam National University) Corresponding author
• Mi-Sook Park(Department of Rehabilitation Counseling Psychology, Seoul Hanyoung University)
• Ji-Woo Seok(Department of Counseling Psychology, Honam University)
• Eun-Ye Kim(Department of Education, Chungnam National University)
• Ji-Hye Noh(Bioimaging Research Team, Korea Basic Science Institute)