"I got so much so fast that nothing really excited me anymore. I kind of took matters into my own hands and was creating drama in a very dangerous way," People quoted Richie, as telling Sawyer.
"I think I was just bored, and I had seen everything - especially when you're young, you just want more. At 18 I had just been doing a lot of cocaine," she added.
The Simple Life star further said that she got treated for the coke addiction, but by the time she reached her early 20s, she was dealing 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. This isn't the life ... this was heroin. It's been four years [since I've touched heroin] and almost nine years [since touching cocaine]," she said.
Richie, who recently confirmed reports that she is pregnant, said that she has been happy and content since she got rid of the addiction.
"I'm happy for the things I have accomplished. I'm happy I'm not in that state anymore," she said.