London, April 29 : Former Atomic Kitten Kerry Katona thought she was an alien during her five-year struggle with bipolar disorder.

The singer, who was at the Oxford Union with hubby Mark Croft to deliver a talk, revealed the effects the manic depression had on her.

"I sat on the bed and said, `Mark, I'm an alien' - and I really thought I was an alien," the Sun quoted her as saying.

"I didn't brush my teeth for a week. It's part of my personality," she added.

The 28-year-old got back with her better half last month just two weeks after they split.

The disorder is a psychiatric diagnosis that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated mood clinically referred to as mania or, if milder, hypomania. (ANI)