Britney: 'What was I thinking?'

Britney Spears has admitted that she can't explain her erratic behaviour over the past two years.

Speaking during a 90-minute MTV special titled Britney: For The Record, the popstar confessed that she had made mistakes during her highly publicised breakdown, including shaving her head and being hospitalised after a confrontation with police.

She said: "I've been through a lot, and there's a lot people don't know. I sit there and I look back: 'I'm a smart person, what the hell was I thinking?'"

The 26-year-old continued: "So much has gone on over the last couple of years and there's a lot that people don't know about me that I want them to know.

"I wanted to make this film because I started to feel like I wasn't being seen in the light that I wanted to be seen in. This is an opportunity to set the record straight and talk about what I've been through and where I'm headed."