They might not be able to get over it, but they could make an effort not to depress the crap out of everyone around them. And they certainly should not have children. I mean, why do they do it? They know it can be passed on, and if they are unable to feel joy in anything, why have a baby? It’s not like the baby is going to make them happy.
Again, I am sure that the clinically depressed are really and truly sorry that you have been inconvenienced by their depression.