system
Severe mood swings. Could this be caused by childhood abuse?
human
I have a friend who is presenting with extreme happiness and excitement then goes to crying. He doesn't make sense when he talks and when he types he sounds like a kid who's so excited they tell all the different great parts of a story at once but still sticks to that one story. He was physically abused as a child but could this be more than suppressed emotions overwhelming him all at once? He did keep telling me he can finally feel again and feels amazing.
gpt
DearWe understand your concernsYour friends diagnosis can be done only with the help of detailed case study comprising of past events, traumatic events, family history and present details of problems he is facing. Primarily it appears to be mood swing, but it could be something more deep.As him to record the mood swings in a diary for a fortnight alongwith what caused it or what he did prior to that. Don't assume anything, no presumptions. Then consult a psychologist  / psychotherapit. Wish speedy recovery