中文摘要：

表观遗传学是研究主要受控于DNA甲基化、染色质结构变化的可遗传和逆转的基因组功能的调控。近年来，越来越多的证据表明表观遗传因素在精神分裂症、双相障碍、药物成瘾等重性精神障碍的发病中扮演着重要角色。文章综述了表观遗传现象的分子机制，介绍了表观遗传修饰与复杂性疾病的关系，并在此基础上对重性抑郁障碍（Major depressive disorde,MDD）发病的表观遗传调控假说及最新研究进展进行了总结。

英文摘要：

Epigenetics refers to the heritable, but reversible, regulation of various biological functions mediated principally through changes in DNA methylation and chromatin structure derived from histone modification. Recent research indicated that epigenetic mechanisms may play vital role in etiology of major psychosis, such as schizophrenia, bipolar disorder and drug addiction. With brief introduction of epigenetic molecular mechanisms and relevance of epigenetics to human commom diseases, this review focuses on epigenetic hypothesis and some supporting evidence which are recently emerged in major depressive disorder （MDD）.