Moreover, there are sex differences in the prevalence and symptoms of MDD and BD (Baskaran, Cha, Powell, Jalil, & McIntyre, 2014; Jogia, Dima, & Frangou, 2012; Labonté et al., 2017; Shors, Millon, Chang, Olson, & Alderman, 2017), while sex differences in the expression of PACAP and its receptors are also present in rodents (Mosca, Rousseau, Gulemetova, Kinkead, & Wilson, 2015; Ressler et al., 2011). Here, ADCYAP1 is linked to major depressive disorder.