This document summarizes Greek and Roman mythological figures who experienced madness or insanity, including Orestes, Cassandra, and Heracles. Orestes was driven insane after killing his mother at Apollo's command and being pursued by the Furies. Cassandra was cursed by Apollo such that her prophecies were never believed, driving her mad. Heracles experienced a brief period of madness induced by Hera that led him to kill his children, after which he had to perform his famous twelve labors to atone.