I dug myself into psichology and multiple personality disorder is one of my target.
The bad news is according to official stat. 99% of multip.pers.disorder (split personality) caused by childhood abuse. We are talking serious beating, torturing, or sexual kind…
In order to cooperate with hard situation the brain creates a new personality or more.
If you read tabloids nowdays you'll know a lot of stars have multip. pers. disorder. for example Britney Spears.
Changes between personalities happen when severe stress, trauma happens or something remind them (clicks them) to the childhood trauma.
I think this shed some light to how MK ultra actually works.