Multi-personality disorder?

My fiancee had a traumatizing childhood. She told me that in order to deal with the pain she "created" another person inside of her. She even gave this other person a name. This "other person" is very careless, loves to hurt other people emotionally, and shows no remorse for her actions. On the other hand, my fiancee is very kind and shy, but depressed. She goes through phases where she "lets out the other person" and I get to question her - which is how I learned how she thinks. I really want to help my fiancee be happy again or at least get rid of that other personality. What's wrong with her and what can I do to help???

This kind of Dr Jekyll and Mr Hyde syndrome occurs in borderline personality disorder. But encourage your girlfriend to consult a psychiatrist for diagnosis and perhaps treatment.

Read more about borderline personality disorder.