And after a series of bizarre incidents captured by paparazzi including the shaving of her head and appearances wearing a short skirt without underwear resulted in a month-long stay in an exclusive rehab facility in Malibu, California.

Spears recently posted a message on her Web site saying she had been acting like a "bad kid running around with ADD (attention deficit disorder)."

She wrote: "Recently, I was sent to a very humbling place called rehab. I truly hit rock bottom. Till this day I don't think that it was alcohol or depression,".

She also hinted at her dislike of heiress Paris Hilton.

In the message on her website Spears refers to unhealthy friendships she acquired after her split from Kevin Federline.

Spears wrote: "Being in that vulnerable state and taken to dinners and parties with friends and finding out later you paid for everything was a huge learning lesson for me.

Spears and Hilton, who was released from her 23-day prison sentence for a driving charge, after serving just three days, were often seen out partying right after the pop star's break up.

After just a few weeks of wild partying together their friendship quickly cooled, and they have not been seen together since.

Spears got a divorce from aspiring singer Kevin Federline last November, two months after the birth of their second son, Jayden James.