Frank Joseph Ayd Jr. was an American psychiatrist known for introducing the first antipsychotic medications into US clinical practice, being granted the first permit from the Food and Drug Administration to use Thorazine for schizophrenia. He took part in writing more than 50 books and authored over 400 articles. The “Ayd’s Lexicon of Psychiatry, Neurology and the Neurosciences” became a standard reference.