Demi Lovato pretended to be happy during her stint in rehab last year (10) because she was desperate to be released from the clinic.
The singer/actress quit a tour with the Jonas Brothers at the end of October 2010 to treat "emotional and physical" issues, which she later revealed included an eating disorder and self-harm.
Lovato left rehab in January (11) and has now opened up about her three-month stay at the centre.
The star admits she decided to "fake" her willingness to receive the treatment when she arrived in a bid to increase her chances of an early release.
She tells MTV News, "When I first went into treatment, I didn't want to be there, and I was kind of like, 'I'll just fake it until I make it.'
"I stayed in there, and I started believing that I was in there for the right reasons. And even though I didn't want to be there at the time, some girls might not want to get help, but if they fake it till they make it, hopefully they can get the help that they need, and they can start to believe it, and they can actually see one day that it's actually the right thing that they're doing.
"I have days where I'm cranky, but I definitely want to be there for my fans and step outside and shake their hands and be there for them too, because I'm now a role model, and I want to be there for them.
"I would say: Speak up, and don't be afraid to get help, because it could save their lives."
And Lovato has credited her rehab stint with changing her outlook on life, adding, "I feel like I'm a totally different person today, and I've grown up a lot, and I've overcome a lot, so I'm excited about where I am in my life today."