Mania (deity)

In ancient Etruscan and Roman mythology, Mania, also spelled Manea, was a goddess of the dead, spirits and chaos: she was said to be the mother of ghosts, the undead, and other spirits of the night, as well as the Lares and the Manes.
She, along with Mantus, ruled the underworld.
Her counterpart in Greek mythology, also named Mania, was the goddess of insanity and madness.
Mania, along with the Lares, were given offerings to turn their focus so they would not harm the living, leaving the people spared. This event occurred during Saturnalia.

Etymology

Her name links her to the Manes, Mana Genita, and Manius.
Both the Greek and Latin Mania derive from PIE *men-, "to think." Cognates include Ancient Greek, and Avestan.