The association of oxytocin with disorders comprising disturbed social functioning is not limited to autism (Guastella et al., 2010; Preti et al., 2014), but was also apparent in relation to schizophrenia (Feifel et al., 2012), depressive disorders (Scantamburlo et al., 2007; McQuaid et al., 2014), and suicidal behaviors (Lee et al., 2009; Jokinen et al., 2012). This evidence concerns the gene OXT and depressive disorder.