These findings strongly support the role of NPY as a resilience factor and, based on the expression of this neuropeptide and on the behavioral profile displayed by maternally deprived rats, we hypothesize that maternal deprivation on PNDs 3 and 11 leads not only to increased vulnerability to emotional disorders but most likely to other psychopathological conditions as well, including PTSD and alcohol/drug abuse. This evidence concerns the gene NPY and post-traumatic stress disorder.