While most of the cast from Saved by the Bell have remained in the spotlight, Lark Voorhies has largely been out of sight. The former teen star, known to a generation of fans as the fashionable Lisa Turtle, denies anything is wrong, but after a bizarre Yahoo! video went viral earlier this year, some questioned whether drugs played a role. Voorhies adamantly denied it. Instead, her mother says, she has been diagnosed with bipolar disorder. In a series of interviews with People, it was clear something wasn't right. Voorhies, 38, would frequently stop mid-sentence and stare off, often mumbling to herself...