Werd,
If you're going to be with the guy, and he may very well be a good potential mate, make sure to learn everything you can about the condition. It probably would also be a good idea to accompany him on his doctor visits, as well as monitoring his medication.
It isn't the same thing, but my aunt was married to a man who she later came to learn suffered from depression since an early age. People are clever and can hide many of the tell tale signs.
98% of the time he was fine. But it just takes a slip up for them to become dangerous to themselves and others. In her case it was very serious.