Dr. Nolan Ryan Williams, neuroscientist/psychiatrist, pioneer of Stanford SAINT protocol for depression, dies by suicide

[haele]

10. FWIW, Suicide is not always an escape from severe depression

It is a way of ending a future that would be intolerable to the person.
A future of constant Pain
A future of Disgrace
A future without an Identity or Anchor.
A future full of despair.
A future watching failure after failure of everything you've been working for, and you just don't have the energy to start over.
Or just an overwhelming "I want the world to stop".
It can be a selfish impulse, it might be a temporary weakness, it could be staring into a long, dark, lonely time of the soul and stepping out into it.
It could be thinking "there's nothing more I can do to support those I care for than to die" - or a big ol' angry "F*** all you takers, I'm out of here" when one realizes they're surrounded by moochers, feckless idiots, or emotional vampires.
Suicide is a complex choice on how to deal with a burden one just doesn't feel they can deal with anymore.
Yes, we all think about that step, that trigger, that twist of the wheel and then come to ourselves. Some people are considered "suicidal" due when making a snap decision to push limits or reacting to resolve a catastrophic situation without regarding their own safety, especially if they get injured or die for their actions. No "rational" person would be driven to do what they did.
The complexity behind a suicide is one of the reasons there's such guilt and stigma involved with the act. But it's still a choice that person made, no matter how flawed we might perceive it after the fact.