You are not supposed to help him. You cant anyway. If you like him, tell him that. If you know that it wont work out, then dont. In the end of the day you are own your own. You go out, you hang out but thats as far as it gets. There is no must in helping others in such matters. Proper government institutions supposed to take care of that, but he supposed to contact them by himself if he really feels he needs to. Otherwise it might end up really bad for you. he might have been just joking, alot of people dont mean what they say. Im pretty much sure he doesnt have the balls to commit suicide. What i would suggest, is buy him a book that handles this matter. Maybe Hard Love or something else...