The Possession of Joel Delaney (1972)

Norah Benson (Shirley MacLaine), an affluent socialite living in Manhattan's Upper East Side, seems to be living the perfect life as a divorced mother of two. After her mother's suicide, she becomes a mother figure to her younger brother, Joel Delaney (Perry King). However, Joel begins to begin to act strangely. He tries to attack a man and is taken to a mental asylum. He loses his free-spirited kindness in exchange for a turbulent personality. After the twin shields of her affluence and naiveté have been broken down, Norah seeks the help of a spiritualist to attempt to exorcise the spirit of a murderer they believe to be possessing Joel. But Joel turns on Norah and threatens her life and those of her children.