Its a nice thought, but people in this position often don't want help.
My best Friend was doing a PHD in a Biochemistry related field at University College London back in 2003. He was an outgoing person, had a hot girlfriend and lots of friends. He had a what seemed like a great life and an even better future.
One night we went out together and had a great night. We went our separate ways about 4am and I we arranged to meet at 5pm the next day.
At 2pm the next afternoon I got a call from his flat mate saying that he had committed suicide. He had access to all kinds of chemicals and substances at the as part of his PHD and he had been taking little bits for months and months and making a potent cocktail of poison. He drank the poison and died instantly.
There was no note, no explanation and no reason anyone knew. I was the last person (friend) to see him alive.
I guess I'm saying - even balanced, successful people have their reasons and you will never know or be told what they are.