My meltdown was not because of a break-up: Demi Lovato

Los Angeles: Teen star Demi Lovato has rubbished rumours which linked her meltdown to a break-up,saying there were underlying issues behind her depression.

The 18-year-old songstress hit a back-up dancer named, Alex Welch, in the middle of a flight last October, before pulling out of a world tour with the Jonas Brothers. She later checked into rehab to deal with "emotional and physical issues".

It was rumoured that Lovato was struggling to deal with her split from Joe Jonas and had lashed out at Welch in a jealous rage, reported Elle magazine.

"When you punch someone on a plane, enough is enough. I just felt like she betrayed me. That's the bottom line. I was completely out of line all summer. Just the worst attitude--totally ungrateful. (But) I wouldn't credit my meltdown to a guy. There was so much other stuff in mylife," she said.

The Sonny With a Chance star sought treatment for depression and an eating disorder and was subsequently diagnosed with bipolar disorder.