Eighty years ago the largest genocide ever occurred in Nazi Europe. This began with the mass extermination of patients with neurologic and psychiatric disorders that Hitler's regime considered "useless eaters".The neuropsychiatric profession was systematically "cleansed" beginning in 1933, but racism and eugenics had infiltrated the specialty long before that. With the installation of Nazi-principled neuroscientists, mass forced sterilization was enacted, which transitioned to patient murder by the start of World War II.