Actor Robert Carradine, best known for his roles in “Revenge of the Nerds” and “Lizzie McGuire,” died Sunday at 71. He took his own life after battling Bipolar Disorder, his brother and actor Keith Carradine said, according to Deadline. 3 Robert Carradine and Michelle Meyrink in the 1984 comedy “Revenge of the Nerds.” ©20thCentFox/Courtesy Everett Collection Carradine was part of the legendary acting family, including his father John and brothers Keith and David.