I had a relative who did it many decades ago. Due to an illness he completely lost the eyesight on an eye and almost all of it on the another. One day his sister asked him where he was going, because he wanted to leave, after seeing their father, and he answered with a saying resembling the english "to go the way of all flesh". She didn't took him seriously. That was the last time when somebody saw him ever again.
He was alone, unmarried, in his 50s, and with nobody to take care of him. But besides this, the prospect of him completely losing his vision was devastating. His sister often talked about him and regretted him until the day she died.
For some particular reasons sometime I think that I'm his reincarnation. He died 2 years before I was born.
I also had a neighbor who hung himself at 17. He didn't had a driving licence, as he was under 18, he took the car of his sister's boyfriend and crashed it a little in front of it. He panicked so bad that he killed himself. I alaways feel sad for him because it wasn't something unfixable.