Demi Lovato struggles with trust issues

Teen star Demi Lovato is hesitant to allow new friends to get too close to her because she still struggles with major trust issues triggered by a former bullying hell.

The singer/actress, 19, enrolled in rehab late last year (10) to seek help in battling a string of depression and anxiety issues, and although she insists she is now happier and healthier than ever, she admits she still needs the daily support of her friends, family and fans.

But the Skyscraper hitmaker is learning that not everyone has her best interests at heart.

She tells Parade magazine, "Just be careful who you trust. Sometimes you don't know who you can and cannot trust. I still learn that over and over again."

Demi Lovato recently confessed she suffered a near-panic attack during her first day at rehab, when she realized she'd have to open up and share her innermost thoughts with 25 strangers.

She said, "I have social anxiety issues when it comes to girls my age because I dealt with bullying, so when I stepped into a treatment center, where I was having to live with 25 strangers... I was like, 'Oh my gosh!' I almost had a full-blown panic attack."