Researchers have identified a key epigenetic mechanism in the brain that helps explain cocaine’s addictiveness, according to research funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health.

The study, published in the January issue of the journal Science, shows how cocaine affects an epigenetic process (a process capable of influencing gene expression without changing a gene’s sequence) called histone methylation. These epigenetic changes in the brain’s pleasure circuits, which are also the first impacted by chronic cocaine exposure, likely contribute to an acquired preference for cocaine.