A L.A. County Superior Court judge has signed a "5150," meaning Britney Spears is on a three-day psychiatric hold at the UCLA Medical Center.
There is a "good possibility" it will be extended to 14 days.
There have been several concurrent attempts to get Britney on a 5150. Spears' own lawyers, Anne Kiley and Tara Scott, secured a new psychiatrist for her late last week - and he's the one who triggered the 5150 last night.
At the same time, we're told Britney's mother, father and brother have been "working closely with the LAPD for weeks" to get her psychiatric care.
Meanwhile, a bitter fight is taking place over who is in control as far as making the troubled star's medical decisions.
Insiders say Britney's parents, Lynne and Jamie Spears, are currently not calling the shots in making medical decisions on behalf of Britney.
Right now, it appears Sam Lutfi is in the driver's seat.
Sources close to the case say that after Britney's stay at Cedars-Sinai January 3, she had her lawyers draft up paperwork making it clear she did not want her parents involved in making any medical decisions on her behalf.
Jamie Spears (above) reportedly went ballistic, screaming and swearing at Sam Lutfi - even pushing him physically - right in front of Britney.
As to what paperwork she signed, if any, that's unclear.
If Britney signed a durable power of attorney, that could give someone power to make medical decisions on her behalf in an emergency.
No such document was reportedly signed, but somehow Britney Spears made it clear she wanted Sam Lutfi - not her folks - to make decisions.
Right now, the doctors at UCLA are working with Osama, not Jamie and Lynne Spears. Lawyers are involved and a judge will have to sort it out.
More to come throughout the day. Follow the jump for more details on how Britney was hospitalized in the early hours of the morning ...