Epigenomic Studies of Substance Use

Drug addiction is a devastating mental health problem with an alarming increasing prevalence. Underlining biological mechanisms of drug addiction are abnormal neuronal and brain activity following acute and repeated drug exposures. Altered gene-expression patterns are found in reward-related brain regions of drug addicts and in animal models. These changes in gene expression are responsible for morphological and molecular abnormalities in reward-related brain regions. Epigenetic modifications such as DNA (hydroxy)methylation and histone mark modifications are upstream regulators of gene expression. Global and site-specific changes in epigenetic markers are observed in addiction. Here, we discuss recent findings linking epigenetic changes to drug addiction in both animal and human studies. We will speculate on potential directions for diagnosis and therapeutics of drug addiction using epigenetic screening and epigenetic-modifying drugs.