Epigenetic biomarkers in neuropsychiatric disorders

Neuropsychiatric disorders are complex, heterogeneous conditions resulting from the interaction of factors including genetic, neurobiological, and cultural factors, and life experiences. Increasing evidence has suggested that epigenetic modifications are involved in the pathophysiology of major neuropsychiatric disorders, such as schizophrenia, bipolar disorder, and major depressive disorder. A modern definition for epigenetics is the structural adaptation of chromosomal regions, which may enhance or impair DNA transcription. There are multiple layers and players in epigenetics which are associated with human neurodevelopmental diseases. Some of the most studied epigenetic mechanisms are DNA methylations, histone modifications, and microRNAs (miRNAs). In this chapter, human studies that utilized central and peripheral tissues to investigate DNA methylation, histone modifications, and miRNAs in the aforementioned three major neuropsychiatric disorders are reviewed.