Demi Lovato says she was misdiagnosed with bipolar disorder a decade ago Entertainment Wed, Mar 17, 2021 'I've been told that they think I was misdiagnosed when I was 18,' said Demi Lovato Demi Lovato came out publicly detailing her bipolar disorder diagnosis to almost a decade ago. In 2011, the Camp Rock star said she is taking treatement for the mental health ailment after teaming up with multiple organisations to help create awareness around it. Clearing the air, the singer/actor said she was misdiagnosed with the disease in her new documentary Dancing with the Devil. "I've been told that they think I was misdiagnosed when I was 18," Lovato said on camera.