In 1969, Cain's mother married film director Christopher Cain, who adopted Dean and his brother, musician Roger Cain; the family moved to Malibu, California.
V roku 1969 sa Cainova matka vydala za filmového režiséra Christophera Caina, ktorý si adoptoval Deana a jeho brata (hudobník Roger Cain) a rodina sa presťahovala do Malibu v Kalifornii.