From my (in this case accurate) recollection.

Her ex Kevin Federline told reporters she has multiple personalities.

A report said that when Brittney put on certain wigs "watch out" because she was going to be a different person.

Some reporters saw Brittney at times randomly using a British accent for no apparent reason. Madonna reportedly does the same thing.

In an interview with Diane Sawyer, Brittney jumps into a different personality and quickly regains control and starts crying over it (now famous clip).

All this points to MPD/DID, which usually results from severe trauma as a child and has long been implicated in MK Ultra.