Genética e depressão fatore epigenéticos que modulam a incidência do transtorno depressivo maior

Abstract

Psychiatric disorders such as depression and anxiety are the most common amongst mental illnesses and affect over 200 million people worldwide. Even though they have very distinguished clinical presentations, these disturbances are intimately connected in their pathogenesis. There are several different physiological factors that can affect the clinical presentation of these conditions. Epigenetic changes are partially responsible for specific patterns of gene expression. However, these alterations do not involve changes to the DNA sequence of the individual. Amongst many hypotheses about the pathogenesis of depression, especially those that consider epigenetic alterations, the most common theories surround topics such as chromatin remodeling, DNA methylation, and non-coding RNA and their respective

interactions with the environment, as well as its consequences in the showing of symptoms of depression. The present study intends to elucidate, through the revision of existing studies, in which manner the mechanisms of chromatin remodeling, such as acetylation, deacetylation, methylation and demethylation affect gene expression and, as a consequence, its relation to the prevalence of the depressive disorder, as well as analyze the contribution of DNA methylation and non-coding RNA in the regulation of epigenetic mechanisms and their effect on MDD. The diagnosis for depression doesn’t rely on biochemical tests or blood works, but on the evaluation of symptoms expressed by a patient. However, when we discuss epigenetic factors, molecular diagnosis techniques may apply. Key-words: Depression; Genes; Epigenetics; Diagnosis.