If pilot suicide is the primary cause of airplane crashes now, it will remain so in the future, but not for long. There will be a solution. If I was still employed as a pilot today, I would be giving that some very serious thought.
There are a lot of intelligent and knowledgeable people on this thread. If the discussion has not come around to potential solutions by now, that may be a good indication of just how tough this problem is. It may be the defining one of the future of commercial aviation.