A woman I knew had one personality that would basically be a party girl with all it's connotations and then turn to being a highly religious god fearing woman

A woman I knew had one personality that would basically be a party girl with all it's connotations and then turn to being a highly religious god fearing woman, again, with all the connotations that go with it. She even had 2 different names. One for each personality. And she referred to the 2 personalities as if they were 2 distinct individuals. I happen to catch it by accident as she tried to keep the different personalities separate so she would try to keep the related social groups separate too. I think she was aware of the 2 and thought nothing of the transformations from one to the other which she made with out much fuss. My guess is that she had such an overwhelming need to be one, but she could not let go of it, that she created a second personality to satisfy her needs. It was very strange to deal with her in different settings. The personalities were different enough that I could tell who was who by looking at her. I've never met someone like that again. She was well aware of it so I don't think it was a mental condition that needed to be treated. I've often suspected that there must be a few people that have such a deep need to be someone else that they get lost in what ever second personality they create and lose touch with reality only to be brought back by their real life situation. It might not be multiple personality disorder but it has to be a flavor of it.