It’s a semi popular head-cannon on Tumblr and Twitters that Butters Stotch has D.I.D or OSDD.
Based on his various personas and Victor Chaos in the Post Covid special.
Butters was diagnosed with D.I.D by Doctor Janus but Doctor Janus was a insane man who himself had a split personality and all Butter’s did was play pretend characters that his family thought where multiple personalities because they are stupid.
I can see it the abuse he experienced could lead to DID.
Butters is pretty obviously just playing. And as Vic Chaos he clearly knows that he used to be Butters Stotch. It’s not like Cartman who genuinely believes that Mitch Conner and Cupid Me are separate entities from himself.