Demi Lovato says she changed her lifestyle, in part, so she could be a good role model for her young fans.

The singer, actress and "The X Factor" judge went to rehab when she was 18 to deal with substance abuse and various other personal issues.

However, now that she is a little older and wiser, Lovato said she feels a responsibility to turn her life around and set a good example for those who want to be like her.

"I think no matter what way you say it, you're gonna be in the public eye and people are gonna look up to you," she told the celebrity news website Hollyscoop.

"I just decided that I turned 21, I gotta be an adult. I've gotta act like one and here I am."

Lovato also said she hopes her upcoming autobiography will help her fans avoid the mistakes she made.

"Sometimes when you go out and you party it can also be a way of self-medicating and it can lead to dangerous things. I want to put my story out there so no one goes down the same path I [did,]" she said.