In some cases, depression is accompanied by hypocortisolemia (Bremmer et al., 2007; Vreeburg et al., 2013; Moreira et al., 2016; Galvão et al., 2018), which may be induced by prolonged use of particular type of antidepressants, such as mirtazapine—a selective antagonism at 5-HT2 receptors (Schüle et al., 2006). This evidence concerns the gene HTR2A and depressive disorder.