Britney Spears' now infamous 2007 mental breakdown was caused by the singer's excessive use of amphetamines, her former manager Sam Lutfi alleges in a lawsuit against Spears.

Lutfi is suing Spears for the 15 percent of her earnings he claims she promised him during the eight months he worked as her manager in 2007.

Lutfi's lawyer, Joe Schleimer, gave his opening statement Thursday and told the jury that Spears' use of amphetamines was the cause of her downward spiral.

"Most of the things that went wrong related to that habit," Schleimer said. "My client sometimes spent 24 hours a day to prevent Britney from using drugs."

According to the lawyer, Lutfi agreed to be Spears' manager only under the condition that she stop using drugs, allegedly telling her "I don't want to be your manager when you overdose."

Schleimer said Lutfi brought drug-sniffing dogs to Spears' home to rid the house of any substances, and the dogs found a baggie of white powder that Spears admitted was crystal meth. The dogs also found drug residue in the home's carpets, which Lutfi later had removed.

The lawyer also claimed that Spears' forced hospitalization in 2008 came after she had been "popping [prescription] pills for 36 hours" and locked herself in a bathroom. Schleimer told the jury that Lutfi was "left alone to deal with this crisis."

Spears' mental issues have continued over the last few years, and she has remained under the conservatorship of her father. In August, she requested to a judge that the conservatorship be partially lifted so she could have control of her personal affairs, but the judge declined at the recommendation of her doctors.

TMZ reported at the time that the reason her doctors were uncomfortable with lifting the conservatorship is that Spears "has a serious medical issue that prevents her from making consistently sound decisions" and affects her personality.

Tags
Britney Spears