OXTR and psychiatric disorder: Recent studies have identified that oxytocin (OT) and the oxytocin receptor (OXTR) exert important roles in the regulation of complex social behaviors such as maternal behavior, mating, aggression, attachment, sexual behavior, as well as in psychiatric disorders characterized by social deficits (Ferguson et al., 2001; Bakermans-Kranenburg and van Ijzendoorn, 2014; Hoge et al., 2019).