Britney Spears has opened up about suffering from anxiety and shyness.
The pop princess - who went through a public meltdown and shaved off all her hair in 2007 - revealed in her new documentary I Am Britney Jean that she is so shy that she is "not really made for this industry".
"I have always been kind of shy, since I was a little girl. It's who I am to be modest, so I really can't help it," said the Piece Of Me singer.
Despite her raunchy stage shows, Britney confessed she switches to an "alter ego" when she performs.
"I turn into this different person seriously. Bipolar disorder," she said on the show, which aired on E! in the US.
The 32-year-old also opened up about her difficulties at the height of her fame, explaining she felt isolated.
"There was a time when I couldn't leave the house without about 20 cars following me. It was a very difficult time for me... I felt really alienated," she said.
"They [the paparazzi] kind of eased up after I didn't come out of the house for like two years," she quipped.
Britney, who is dating lawyer David Lucado, was open about her feelings about intimacy. "I love sex. I think sex is great, but I feel a little different about it now that I am older," said the mother-of-two.
She added: "Sometimes I feel like I am 20 and sometimes I feel like I am 50."
The documentary followed Britney as she prepared for her two-year residency at Planet Hollywood Resort And Casino in Las Vegas, which starts later this month.