Britney Spears has confessed she now regrets her highly-publicised erratic behaviour - including the famous head-shaving incident.

The Toxic hitmaker admits in an upcoming MTV documentary, For The Record, that she has made huge mistakes, but is grateful she has a chance at a comeback.

Spears was forced into a psychiatric hospital earlier this year following a public breakdown, including shaving her blonde locks and a showdown with police at her Los Angeles home. She also divorced Kevin Federline and publicly battled him for custody over their two sons.

But Spears is determined to show fans she is on the road to recovery.

She says, "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."

She adds, "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?'"