AceShowbiz -

First, second, and now third. Hot on the heels of her first two interviews with ABC News' Diane Sawyer, during which she talked about her pregnancy and DUI sentence, Nicole Richie has in the third and final installment of the interview revealed that it was her life as a Beverly Hills socialite that led her to drug use.

"I got so much so fast that nothing really excited me anymore," the 25-years-old star revealed. "I kind of took matters into my own hands and was creating drama in a very dangerous way. I think I was just bored, and I had seen everything, especially when you're young, you just want more."

And so she started to take drug at her 18th. "At 18 I had just been doing a lot of cocaine," Nicole admitted, only to find herself addicted to heroin before she at last came to such realization that she had to be sober. "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. It's been four years (since I've touched heroin) and almost nine years (since touching cocaine)."

And when she reached the clean stage in her life, the reality TV star said, "I'm happy for the things I have accomplished. I'm happy I'm not in that state anymore."

Greater than that, Nicole claimed she never blamed his father Lionel Richie who said he's not a good father for her because he always went touring in concert and rarely in home to be with her. "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."