Interestingly, dopamine receptors and MCH can interact positively in the regulation of some behaviors including in animal models of cocaine addiction and schizophrenia (Chung et al., 2009; Chung et al., 2011a), while antagonistic interactions are also observed (Georgescu et al., 2005, see also Tyhon et al., 2008). Here, PMCH is linked to schizophrenia.