Epigenetic involvement in psychiatric disorders and psychiatric drugs

Abstract

For a long time scientists have sought the origin of psychiatric diseases in genetic patterns. Genomewide association studies delivered a wide range of candidate genes for depression, schizophrenia and bipolar disorder, but as increasingly more association studies attempted to pinpoint the etiology of such disorders to genetic polymorphisms, it became clear that the make-up of our genes does not comprehend the full story. Findings are often inconsistent and in some cases, genotype per se does not affect disease-risk, but modifies the deleterious influence of environmental stressors on the risk of developing disease. From epidemiological research it has long been known that environmental factors and significant life events increase the likelihood of developing psychiatric symptoms, indicating a gene-environment interaction. In the field of epigenetics genes and environment converge, providing better insight into mental disorders. Understanding the role of epigenetic mechanisms in psychiatry is of key importance for psychiatric treatment, since it may be reversible under the influence of social factors, drugs or behavioral interventions. In addition, a deep understanding can lead to development of better medication, and better comprehension of the medication currently in use. The aim of this review was twofold; to get better insight into the involvement of epigenetic mechanisms in psychiatric disorders, and to establish the future prospects for epigenetic psychiatric treatment. The reviewed literature suggests that epigenetic mechanisms mediate the development of psychiatric symptoms and moreover, that they may explain several neurobiological hypotheses on psychiatric behavior. In addition, several widely known psychiatric drugs have epigenetic action, and research with experimental compounds with epigenetic targets is promising, albeit limited.