Perhaps the company could frame some form of 'Behaviour Code'? You often see these in places, such as 'bad language will not be tolerated and abuse of our staff is unacceptable' etc., etc.. No way am I a psychiatrist, but I once lived with (was married to for a nightmare few years)a depressive man who descended into Bi-polar disease and it does sound similar. Steer clear...… and he does need help by the way, i.m.o..