Singer Susan Boyle has revealed that she was diagnosed with Asperger's last year and now feels relieved and more relaxed about herself.

In an interview with The Observer, the 52-year-old who rocketed to fame after appearing on Britain's Got Talent in 2009, said that she was misdiagnosed after complications at birth and has actually had Asperger's, a high-functioning form of autism.

She received the diagnosis a year ago but has kept it secret. "It was the wrong diagnosis when I was a kid," she said. "I was told I had brain damage.

"I always knew it was an unfair label. Now I have a clearer understanding of what's wrong and I feel relieved and a bit more relaxed about myself."

Boyle was called "Susie Simple" while growing up in her home town of Blackburn, West Lothian and was bullied as a child because she was "different" from her classmates.

"I went to seek a diagnosis from a Scottish specialist," she says. "Nobody told me to. I thought I had a more serious illness and couldn't function properly."

Asperger's can make sufferers anxious because of their inability to deal with situations which others can easily handle. The singer has also suffered from depression and mood swings and acknowledges her own vulnerability and need for support.

"I am not strong on my own," she admits. "When I have the support of people around me I am fine. I have a great team."