I had a friend who committed suicide in his early sixties after three years of not being able to land a decent position. He was amazingly qualified to do a ton of things. Age discrimination was at play here.
He actually went back to school and kept a positive attitude through all of it. He'd come over to my office and we'd have long chats. I'd get him involved in what I was doing and did my best to keep him motivated. I even paid for a two week Solidworks course hoping to help open new doors for him. I would give him access to my machine shop and shoved him into the world of modern mechanical design and manufacturing.
In the end he could not cope with no longer being "useful" and took his own life before finishing the course. I had no idea and saw no sign of what was going on in his mind.
I still can't believe the loss.