NPY and post-traumatic stress disorder: Low levels of NPY are found to contribute to chronic PTSD (Rasmusson et al., 2000; Sah et al., 2009; Sah and Geracioti, 2013; Tural and Iosifescu, 2020) and the efficacy of NPY administered intranasally toward relieving PTSD symptoms is supported in empirical studies (Sayed et al., 2018) earning it the name “resiliency hormone” (Sah et al., 2009).