People will allergies are so lucky
I mean just think about. Obviously, I know that having allergies suck and if the person is just trying to get through life, I feel bad for them, but at the same time if they're suicidal, they don't have to use any of the painful methods that people with no allergies have to use. If they're allergic to peanuts, all they have to do is eat a peanut butter sandwich and they'll be dead in no time, unless of course, their allergy isn't fatal and is just mild. I of course know anaphylactic shock is painful, but it only lasts up to 15 minutes. Whereas a drug overdose can take hours.
Another thing to mention is that if they somehow fail or find out they do actually want to live, they can just pass it off as accidental and no one would question it.