That's according to the tabloid, News of the World.

Britney Spears is supposedly going through such an awful time at Promises rehab center that has claimed that she's the antichrist and that she's on suicide watch after an attempt on her own life.
Britney Spears was seen "crying, and shouting, 'I am the Antichrist!'"
A source told News of the World that Britney Spears tried to kill herself late Saturday night, after the Antichrist incident.

The 'friend' of Britney Spears told the tabloid, "The clinic people just didn't know what to do [when she ran around claiming she's the Antichrist]. Then she started screaming, ‘I'm a fake! I'm a fake!' It must have been really frightening. When she tried to hang herself it was more a cry for help."

All Headline News reports that the Saturday night suicide attempt wasn't the first for Britney Spears and that she actually tried to kill herself the same night that she now infamously shaved her head.

Another source told People Magazine, "He cares a lot about her. Britney scared everyone pretty bad. Kevin is worried that's for sure. Kevin just wants her to be OK."
Spicy
Source: ActressArchives