Epigenetic mechanisms in the pathophysiology of psychotic disorders.

Epigenetics is the study of chromatin-the physical material that forms chromosomes, composed of DNA wound around specialized histone proteins-and of how the modification of chromatin acts to establish stable states of gene expression in a cell-specific manner. Chromatin is regulated through three mechanisms: DNA methylation, histone modification, and RNA interference. These basic biological processes form the molecular interface between the genome and the environment, contributing to the regulation of gene expression in health and disease. Investigation of epigenetic mechanisms is yielding exciting insights in many areas of medicine, and a large and rapidly growing literature describes epigenetics as central to many aspects of the pathophysiology of psychotic disorders. This article first discusses speculative points as to why the mechanisms of epigenetics may be satisfying explanatory mechanisms in the etiology of psychotic disorders, then details emerging experimental evidence of roles for the three types of epigenetic mechanisms in these illnesses, and finally discusses these mechanisms as potentially compelling areas of research for the development of future treatments.