Elon Musk said that his first flight to Mars will be a one way trip where it's likely the crew will die. I feel like some suicidal people would be totally up for something like that because it would give you something to do with your life that helps a lot of other people. I am not against this if that's what they really want to do.

But one problem with being suicidal is the idea that "you can't escape yourself", and this is something that can effect and demotivate everyone even if you don't have depression. In my opinion people with depression and people who are suicidal but won't benefit should not be sent on missions like this. While you can't completely escape these feelings, people can change and these people's lives can be made a lot better. I think it's important to help other people and not just send people who have given up to die. Everyone can get new education and skills be it through school or just new experiences, and with a lot of work a lot of people will be able to find new meaning in their life so we shouldn't just be firing them into space because they're unmotivated at the moment.

But that's just my opinion, I'm don't know very much about mental health.