CRH and Anxiety: Maternal separation, considered the archetype of early life stress, is associated with alterations in methylation patterns in several genes that are implicated in anxiety (Murgatroyd et al., 2009; Kember et al., 2012; Wu et al., 2014)—notably corticotropin-releasing factor (CRF) and its receptor (Chen et al., 2012; Sotnikov et al., 2014).