ADCYAP1 and major depressive disorder: For example, PACAP-knockout mice exhibit increased locomotor activity, anxiety/anxolytic phenotypes, depression-like behavior, deficits in learning and memory, cognitive impairment (Hashimoto et al., 2001, 2009; Tanaka et al., 2006; Ishihama et al., 2010; Hattori et al., 2012; for reviews see: Hammack and May, 2015; Mustafa et al., 2015; Shibasaki et al., 2015; Farkas et al., 2017; Missig et al., 2017; Reglodi et al., 2018b; Johnson et al., 2020).