The CIA deliberately created split personalities in real human beings as spy weapons, and it's all in declassified documents.

Psychiatrist Dr Colin Ross breaks down how MK Ultra and Project Bluebird used Dissociative Identity Disorder (DID) to manufacture Manchurian candidates: operatives who couldn't reveal mission details under interrogation because a separate alter personality held the information. Even more shocking, two founding board members of the False Memory Syndrome Foundation, the organisation set up to discredit DID, were top-secret-cleared CIA contractors. One of them killed an elephant with LSD. Another's experiments at Harvard produced the Unabomber.

This isn't conspiracy theory. It's admitted to by the US military and CIA in declassified Senate committee hearings.