The 21-year-old star - who has an on/off relationship with Justin Bieber - was admitted to Dawn at The Meadows recovery centre in Arizona on January 5, and spent two weeks at the facility, which treats people aged 18 to 26 years old who are "struggling with emotional trauma, addiction or dual diagnosis concerns."
Her representative confirmed: "Selena voluntarily spent time at Meadows but not for substance abuse."
The former Disney child star was urged to seek help by those close to her amid concerns her partying was getting out of control.
One source told RadarOnline.com: "Her friends and family became increasingly worried that there might be a serious problem with Selena.
"Particularly, her parents. The partying was, at times, wild. They wanted to help her -- and they very much encouraged her to go to rehab. Others very close to her also urged her to seek professional help."
Another added: "It's important to remember that Selena had worked in Hollywood non-stop for six years. She was exhausted. Selena was smart enough to understand that she needed to take control of her life.
"It just got to a point where she needed to get out of Los Angeles, get away from 'the scene' and the pressures of Hollywood, to also get away from those who had, admittedly, become a bad influence on her. Selena needed to take the opportunity to work on herself. She realised she needed help."
Selena - who reportedly "regularly" smoked marijuana with Justin - had been due to tour Australia this month but cancelled the shows in order to "spend time on [herself]." And the brunette beauty is now said to be doing well.
A source said: "Selena is now happy and very healthy and already getting back to work."