[Epigenetic mechanisms in major depression].

The term epigenetics describes mechanisms that can change the function of genes in the absence of an alteration of the actual DNA sequence. Among others, histone protein modifications (methylation, acetylation and phosphorylation) and DNA methylation constitute epigenetic mechanisms. Histone methylation and histone deacetylation in promoter regions of neurotrophic factors that have been associated with depression lead to their reduced expression. The methylation of DNA in promoter regions of genes coding for receptors and neurotrophic factors also results in their reduced expression, as was revealed for depressive disorders. Preclinical studies have shown that maternal care has a crucial influence on the reactivity of the hypothalamic-pituitary-adrenocortical axis of the offspring due to epigenetic mechanisms. These are acquired modifications that can be partially reversed by drug treatment (antidepressants).