NPY and drug dependence: Convergent lines of evidence (Koob and Le Moal, 2001, 2005) suggest that stress [e.g., corticotropin-releasing factor (CRF) and orexin] and anti-stress [e.g., neuropeptide Y (NPY)] systems are involved in the emotional and motivational aspects of drug dependence (see Bruijnzeel, 2012, for an extensive review) and are largely localized to the extended amygdala, a forebrain macrostructure composed of the bed nucleus of he stria terminalis (BNST), central nucleus of the amygdala (CeA), and NAc shell (Heimer and Alheid, 1991; Smith and Aston-Jones, 2008).