It depends on whether the individual is currently capable of rational thought. Those who can accurately calculate that the pain of continuing to live is greater than its benefits, I'd call that a rational basis for deciding to die. When somebody is just depressed, that indicates an extremely abnormal mental state ****ed up enough to override a basic survival instinct all humans normally posses. That or they're so far out in la-la land, that they no longer understand the reality of death in a way that triggers that basic survival instinct. THESE people should be stopped and offered help.

Most people in this state aren't the pansy emo shits whining all over the internet about how their life sucks and telling everyone they want to die. That's usually just a pathetic attempt at getting attention and getting people to validate your existence out of the guilt they might feel if you actually went through with it.

The ones that are actually likely to go through with a suicide are the ones that act severely depressed, but try not to bring it up in conversation if they engage in conversation at all. A telltale sign that somebody may actually be planning suicide, is an apparent personality shift from that of depression and desperation, to one of calm, going with the flow, everything's gonna be OK, kinda mood. If they're in a seriously ****ed up mental state, they're not going to pull that 180 because everything got better overnight, they're probably acting relived because they plan for it to be over soon.

I was suicidal once, many moons ago. I actually ended up making an attempt, and began regretting it moments after, but fortunately someone found me and got me to a hospital and I made it. After that I pulled a 180, because the sudden feeling regret at the attempt snapped me back into reality, making me realize that I didn't want to die. A reality in which my survival instinct kicked back in. Did a lot of changing after that, and haven't had any issues with depression since. I'm honestly ashamed of that phase in my life, in retrospect I can't believe I was ever in such an irrational state of mind. Nothing I've ever experience even comes close to warranting a desire to die. I'm just glad that momentary lapse in logic wasn't the end for me.