Psychostimulants is a loose category of substances that include cocaine and amphetamines which produce temporary increases in alertness or physical activity. SAMHSA estimates place the estimated number of people addicted to cocaine in the United States at over one million as of 2010 [4]. Cocaine and amphetamines are potent sympathomimetic drugs which increase synaptic concentrations of dopamine, norepinephrine, and to a lesser extent, serotonin through multiple mechanisms. The potent reinforcing effects of these medications are thought to be related, in part, to epigenetic changes that can occur rapidly after initial administration. Recent reviews have outlined the spectrum of epigenetic findings, primarily using animal models and postmortem brain tissue, which have implicated a several distinct epigenetic changes occurring with exposure to psychostimulants, including histone modifications [120], as well as changes in methylation at specific genes [20] and changes in noncoding RNA expression [121]. It is also important to note that several recent studies, including seminal work by Feng, Nestler, and colleagues [122,123] have investigated the role of Tet1 and 5-hydroxymethylcytosine (5-hmc) cocaine addiction using animal models. These studies are important because
