Law enforcement sources have told TMZ about the craziness in Britney's house the night she was committed. It involves profanity, nudity, drugs and wild mood swings.

Sources say when the cops showed up, Britney was locked in the master bathroom with Jayden James. Officers saw Britney from the backyard holding Jayden, who did not appear to be upset. Britney refused to come out for nearly three hours. When she did, all she was wearing was panties. Britney was incoherent, screaming at the cops, "What the f*** are you doing in my house? I know who you are." She continued ranting, "I don't need your f***ing help." At one point Britney, whose moods swung wildly from laughter to rage to sobs, hollered, "You will do as I say."

At some point Britney put on a see-through nightgown. Before police took her outside, they wanted to cover her with a sweater, and she screamed, "Don't cover me up. I'm f***ing hot."

Britney's assistant and nanny were present during the standoff. At one point the assistant told the police that Britney had been "popping pills" all day. Her code for medication was "vitamins" and she repeatedly demanded, "Get me my vitamins!" Officers found a bottle of Prozac in her bedroom.

Sam Lutfi arrived and told officers that he and the others around Britney "knew this was coming for a long time," but didn't know how bad it would be.

The assistant also told cops that earlier in the day, Britney showed no concern about attending her deposition and would not heed her warnings to show up on time.

Sam told law enforcement that Britney had been extremely unstable and had recently purchased a house in Malibu on a whim, began moving furniture in and then changed her mind.

As for Jayden James, the reason cops took him to the hospital was because there was a small bruise on his leg. Britney insisted the bruise occurred on Kevin's watch. Police took Jayden to Cedars as a precautionary measure.

We're told police will testify about the insanity at Monday's custody hearing.

And one more thing -- the nanny told cops that Britney would frequently dress up to the nines for no reason. She would walk around the house and change back.