Making sense of epigenetics

The gene-environment interactions that underlie development and progression of psychiatric illness are poorly understood. Despite a century of progress, genetic approaches have failed to identify new treatment modalities, perhaps because of the heterogeneity of the disorders and lack of understanding of mechanisms. Recent exploration into epigenetic mechanisms in health and disease has uncovered changes in DNA methylation and chromatin structure that may contribute to psychiatric disorders. Epigenetic changes suggest a variety of new therapeutic options due to their reversible chemistry. However, distinguishing causal links between epigenetic changes and disease from changes consequent to life experience has remained problematic. Here we define epigenetics and explore aspects of epigenetics relevant to causes and mechanisms of psychiatric disease, and speculate on future directions.