Depression, PTSD and Suicide
If a friend is hurting, and you know, try as hard as you can to reach out and lift them a bit. You may not get another chance. I know it can be very hard to tell sometimes, but try if you can. It is worth the effort.
You will regret it more if you never try. Sometimes people are so deep that they cannot be reached, but you won’t know if you do not try.