Robert Carradine, known for his roles in The Long Riders, Revenge of the Nerds and the television series Lizzie McGuire, has died at the age of 71 after struggling against his nearly two-decade battle with Bipolar Disorder. He was the youngest son of the late American actor John Carradine and the brother of actors David Carradine and Keith Carradine, as well as Christopher Carradine, a former vice president of Walt Disney Imagineering. Carradine made his film debut in the 1972 film The Cowboys before forging a decades-long career in Hollywood across studio films, independent cinema and television. He garnered huge popularity with his role as Lewis Skolnick, the idealistic leader of a fraternity of social misfits, in the 1984 film Revenge of the Nerds, a studio comedy which spawned multiple sequels. Two decades later, he found a new generation of fans, starring as Sam McGuire in the popular Disney television series, Lizzie McGuire.