I've also known a women who did this. She suffered from depression ... and more.
True story.
I took her to my mega church back in the 90's. We were there about 15 minutes when she turned to me and, in a voice I've never heard before, said; "We're not staying for this"
She then got up and walked out.
When we got outside she didn't remember any of it.
She also used to give me pages from a coloring book that were colored for me by one of her personalities. A 4 year old girl named "Sunshine".
I still speak to this woman on occasion. She got over the multi-personalty thing with drugs, but she's a Democrat. So it apparently caused permanent brain damage.