One might also wonder how one's relationship with religion has an effect on this condition. If a person did not believe in a heaven, hell, or "Perdition", would this change how this ailment causes them to react? As it is so rare, I cannot imagine it will ever get studied with the intensity to find out the answer.
In a lighter note, these folks would probably be excellent in a Fantasy Live Action Role-Playing game as a lich or other undead. The glass is half-full, right?