The 41-year-old singer says his erratic behavior late last year -- which included his wife, Jaclyn, calling 911 and claiming he thought he was in the CIA and was supposed to assassinate President Obama in the middle of a psychotic episode -- was a psychotic break that was brought on by alcohol and drug abuse.
"I was hallucinating," he tells People. "I drove around the United States for a month, following an angel that I saw on the hood of my car. In my delusional thinking, I thought my family was involved in ISIS, and that millions of dollars had been taken from me to support terrorism. All of it was nonsense. I was out of my mind."
Three months later and after hitting rock bottom, Stapp began an intensive program in a dual diagnostic facility where he received the diagnosis.
"There's a stigma associated with it," he says about the disorder, which is characterized by periods of elevated mood and periods of depression. "But Jaclyn kept telling me, 'Embrace it. We love you.' It became a big sign of relief, because finally, we had an answer."
He says he is now sober and takes medication for bipolar disorder. He's also in a 12-step program and continues to be in intensive therapy.