Diane Sawyer, in her interview with Nicole Richie and boyfriend Joel Madden
08/04/2007 AT 12:15 PM EDT
's life of Beverly Hills privilege was what led her into a life of drugs as a teenager, she told Diane Sawyer in the third and final installment of the socialite's series of interviews, which aired Friday on 20/20
aired on Good Morning America
"I got so much so fast that nothing really excited me anymore," the Simple Life
star, 25, said about the lavish trappings of being the adopted daughter of musician Lionel Richie.
"I kind of took matters into my own hands and was creating drama in a very dangerous way," said Richie. "I think I was just bored, and I had seen everything – especially when you're young, you just want more."
Hard drugs accompanied the hard partying. "At 18 I had just been doing a lot of cocaine," she said. She sought treatment for that. But by the time Richie reached her early 20s, she said, she needed to deal with an addiction to heroin.
"I, again, made the decision for myself, this is something I have to do. I have to get off drugs," she said. "This isn't the life ... this was heroin."
How long has it been since Richie touched heroin? asked Sawyer. "It's been four years, Richie replied.
And cocaine? "I was 18," said Richie. "That has been almost nine years."
Since then, she says, "I'm happy for the things I have accomplished. I'm happy I'm not in that state anymore."
Given these past problems, Sawyer quoted Lionel Richie as having said, "I think I wasn't a good dad." The musician, 58, had long believed his one job was to bring in the money, so he was always touring in concert rather than being home with Nicole.
"I never blamed him. I think he blamed himself," said Nicole. "It was very humble of my dad to come forward and say, 'I made a mistake.' I love him for that."