PRL and major depressive disorder: The PRL tasks findings of reduced reversals and increased post-reinforcement pause in HET-AS relative to HET-No-AS mice are particularly interesting in light of the reports that PRL performance was reduced in s/s adolescents exposed to childhood stressful life events and also in patients with major depression (Murphy et al., 2003; Taylor Tavares et al., 2008; Owens et al., 2012).