Synthetic hormones like cortisol and oxytocin involved in animal and human stress responses have gained attention in prevention and treatment of PTSD (Koch et al. 2014; Sijbrandij et al. 2015; van Zuiden et al. 2017; Garcia and Delahanty 2017; Birur et al. 2017) and in mothers with postpartum depression and attachment difficulties (Riem et al. 2012; Bakermans-Kranenburg and van IJzendoorn 2013; Kim et al. 2014). Here, OXT is linked to postpartum depression.