Then Stapp became infamous for a very public meltdown that went on for months last year, in which the rocker posted cryptic video messages online about being "penniless" and that the CIA was watching him. He said he placed maniacal calls to 911, the White House and his son's school, and fired off jarring emails and text messages to family and friends. Meanwhile, Stapp said his bizarre behavior fueled Internet rumors that he was on a drug-fueled downward spiral.
"I would have like, maybe a 45-second interval of, 'What's going on,' and then I'd be right back into the psychosis," he added.
Stapp said his psychosis was so intense that he thought he had been programmed by the CIA -- a real-life Jason Bourne -- and he would prowl airports looking for suspicious cars.
Stapp said he first began to "feel different" in 1998. At the time, Creed's "Proof of Life" album had just dropped, but Stapp said he was starting to feel down.
Stapp said he began to battle a cycle of ups and downs, from promoting a new album to feeling depressed and "not focused." In his 2012 book, "Sinner's Creed," Stapp admitted that addiction and depression nearly tore his life apart, leading to a much-publicized 2006 suicide attempt and the disbandment of the band, Creed. The book was supposed to herald his renewed faith and sobriety.
"I didn't want to return to street drugs, and so I deceived myself and knowingly went in to see a doctor," he said. "Having the previous diagnosis, it made it easy for him to prescribe me Adderall, and I began taking that medication, not knowing the consequences that were getting ready to happen."
When he began taking the Adderall, at first "things were fine," Stapp continued.
"It worked temporarily on the problem that I was having," he said. "It did what it was supposed to do. But then it didn't. And so I increased the dosage and I started taking more. And then it stopped working again. And so I started taking more. And I got up to taking double the legal dosage for that medication, 120 milligrams. And that led me right into a full-blown psychotic episode."
Stapp said he also kept going to the doctor for the Adderall prescription a secret from his wife, Jaclyn Stapp, whom he married in 2006.
"I hid it from her," he said. "It was a full-blown relapse, man, and I can make no excuses about that. ... [I] thought that I could manage it this time."
Taking more Adderall than was prescribed, Stapp said, led to his suffering from "delusions, hallucinations, paranoia," and eventually he turned on Jaclyn. He claims he was unaware that one of the side effects of overdosing on Adderall can include hallucinations.
"I thought my own wife was trying to poison me. I made crazy accusations that she had done things to me that she's never done," Stapp said. "My wife was trying to save me. She was trying to help me. And her efforts to help me in my delusional state, I interpreted as part of the grand conspiracy to harm me."
Sitting by her husband's side during the ABC News interview, Jaclyn said she started noticing "little red flags" about his behavior a few weeks after he came back from touring last year. She said it wasn't until she called Scott's pharmacy that she found out he had a prescription for Adderall. When she learned he was abusing prescription drugs, she said she was hurt and asked him to leave because she didn't want him around their three children. She said she told him to go into a detox program, but instead Scott tried to quit cold turkey on his own, which they both said made things worse.
"That's when I checked into the Holiday Inn and I abruptly stopped the medication, and basically that was like throwing fuel on a fire," Scott Stapp said.
It was during this time that Stapp posted a 15-minute video on his Facebook page -- the post has since been removed -- in which he told fans that he was "penniless" after people had "stolen money" from him, so he was living in a hotel and was as "sober as can be."
Now, Stapp said his online video had "no basis in reality." He wasn't penniless or being robbed, he said he was battling a manic psychosis.
"I was in severe pain," he said. "Everything that I thought, I believed in the bottom of my heart... Your delusion has told you that you have no money, you have no home, you have no family and everyone that you love has been trying to harm you, and you believe it."
During his mania, Stapp would stuff his wallet with cash and fill the flatbed of his truck with his gun collection and sports memorabilia, which he said he started giving away with reckless abandon. Stapp said he would pick a homeless person at random, "get him a hotel room, give him $20 and then take off." He said he also gave away some of his prized possessions -- three Salvador Dali sketches -- to a Catholic church in Mississippi on a random manic drive through the South.
He says he was so manic, he doesn't even know the name of the town where he left the Dali sketches.
Jaclyn filed for divorce in November 2014. In the divorce papers, Jaclyn said her husband was "doing so much amphetamines, crystal meth and steroids that he has become a paranoid shell who has threatened to kill himself and harm his family."
At one point during his mania, Scott said he called the White House "two or three times" and he believed the government had programmed him to harm the president. His accusations became serious enough that the Secret Service showed up at the Los Angeles home he was staying in and at his family's home in Florida.
"I had told [the Secret Service] that he had a terrible relapse and we're trying to get him help, and that he was not, you know, a threat, he just needs help," Jaclyn said. "I knew Scott was very sick."
It was around this time that Stapp said his psychosis started to wear off and Jaclyn flew to L.A. to have him seek treatment. Throughout the months-long ordeal, Stapp had been texting with Jaclyn and she with him, hoping it would pull him back.
"I was beginning to have days where I was coming to my senses," Scott Stapp said. "Almost like walking up out of a blackout, going, 'Oh my God, what have I done? What has happened here? Oh my God.' And it was so overwhelming. It was hard to even process. And I felt so remorseful, so shameful, so sad."
Now, eight months later, Stapp said he has been diagnosed with bipolar disorder and he is finally getting the right treatment. He and Jaclyn are now opening up about Stapp's diagnosis, including in a spread in People magazine. He said he is sober and just recently moved back home to Florida, where he and his wife are trying to move forward together.
"There is hope," Stapp said. "When I'm with this woman, I feel like there's always hope, and she's teaching me what real love it and I'm just very thankful for that."
Read more about Scott Stapp's story in the latest issue of People, out on newsstands nationwide Friday.