I have a solution: pass a law that if any pilot gets grounded for mental health issues, then the airline industry (as a whole, in case his airline goes belly-up) has to continue to pay that pilot's salary until he retires.
Isn't this how it's handled in other countries when someone can't work due to medical issues? Surely they have some way of discouraging fraud, probably by making the doctor responsible or perhaps requiring multiple doctors to cross-check.