|Demi Lovato's rib tattoo|
She said: "I've thought about it before because, you know, when I get older I don't know if I want to have rock and roll on my middle finger.
"I'm young and I can rock it now and when I get older I can worry about it later."
Speaking of one inking, a tattoo of her friend's lips on her wrist, she added: "It was just a spur of the moment, stupid decision."
In late 2010, the US 'X Factor' judge checked into rehab to be treated for an eating disorder and self-harm issues and she admits it was a "relief" to be diagnosed with bipolar disorder as it meant she wasn't "crazy".
Speaking on 'Live! With Kelly and Michael', she said: "I was like, 'Oh my gosh, that means I'm not really crazy, there's a reason.'
"And it was just so awesome to be able to pinpoint a diagnosis for the reasons why I was extremely happy and in, like, a euphoric state, and the next month I was in, like, a deep depression.
"I had everything great in my life I had nothing to complain about but I wasn't happy."
Demi's admission to rehab came after she punched one of her backing dancers and she admits she was in a very "dark" place when the incident occurred.
She said: "I got into a situation in a different country when I actually ended up hitting one of my friends. I was just going through something so dark and I was very, very mentally sick.
"So, you know, when I ended after leaving the tour my parents had planned an intervention."