NPY has also been associated with withdrawal from alcohol. Koehnke et al (2002) reported that the Pro7 allele is more common in alcohol dependent individuals with delirium tremors or who have experienced withdrawal with seizures than in alcoholic dependent individuals with mild withdrawal symptoms. Okubo and Harada (2001) reported association of the 5671C/T polymorphism (rs5574) in NPY with alcohol dependent individuals who experienced withdrawal with seizures. Several animal models have also demonstrated that withdrawal from ethanol reduces NPY expression (Bison and Crews, 2003; Thiele and Badia-Elder, 2003, Thiele et al., 2004b; Thorsell, 2007). For example it has been shown that ethanol withdrawal produced significant reduction in NPY protein levels in the central and medial nuclei of the amygdale, cortical, and hypothalamic structures in rats (Roy and Pandey, 2002). Further evidence shows that intracerebroventricular administration of NPY in Wistar rats in withdrawal significantly decreased the withdrawal scores of the rats (Woldbye et al., 2002).
