创伤后应激障碍（PTSD）患者有不同程度的脑结构、功能的病理性损害，而遗传背景对这些异常的影响尚不明确，其障碍之一是PTSD常有抑郁等共病干扰，而传统的行为学测量受主观影响、常会掩盖潜在的基因影响。本研究在前期已构建的海南省心理危机干预及服务网络基础上，选择单纯PTSD、PTSD共病抑郁及正常对照者，以脑结构（基于VBM的3D脑结构分析、DTI）、静息态功能磁共振为内表型，与多巴胺D2受体（DRD2）单核苷酸多态性（SNPs）进行关联分析。目的在于探讨PTSD与PTSD共病抑郁患者脑结构、功能改变共性与差异；考察易感基因DRD2对PTSD特定脑结构、功能的调控作用，初步建立从DRD2不同基因型到特定脑结构、功能模式及行为水平的对应关系；进而筛选PTSD特异的影像遗传学早期识别靶标，本项目可一定程度上为理解PTSD及其共病的分子机制提供新的科学证据。

The abnormalities of brain structure and function may play an important role in the pathological mechanism of post-traumatic stress disorder (PTSD), and the genetic background of these anomalies is not clear. One of the obstacles encountered is that PTSD have also been confounded by psychiatric comorbidity, most particularly depression, and traditional behavioral measurement may cover up the potential impact of gene due to subjective factors. Based on the constructed psychological crisis intervention and service network in Hainan province, we choose PTSD patients with and without comorbid of depression and healthy controls, all participants will have brain structure (VBM-based 3D brain structures, DTI) and resting state functional magnetic resonance examination (amplitude of low frequency fluctuation and intrinsic connectivity network analysis). Take these abnormalities of brain structure and function as endophenotypes, relational analysis with the dopamine D2 receptor (DRD2) gene polymorphism. The objective of this study is to investigate the similarities and differences of altered brain structure and function characteristics in PTSD with and without comorbid of depression;to investigate susceptibility gene specific regulation on brain structure, function of PTSD. We will initially establish the corresponding relationship from the DRD2 of different genotype to specific brain structure, function model and behavior level; and then screen early PTSD-specific imaging genetics target.This project can provides new scientific evidence for partly understanding the molecular mechanism of PTSD and PTSD comorbidity.