At the same time person can be so messed up that they just cannot see a way out, even if it's right in front of them, or (even worse, if that is possible) their fears are illusionary. They can also be very convinced of this, and even convincing to others. This is why we tend to err on the side of discouraging suicide, since it's an irreversible option.

I'm going to try to explain the inside perspective here:

If you cannot see or act on a way out, it isn't a way out, even if you cognitively know it's there.

If you're sufficiently dedicated to rationality, living with constant suicidal depression really, REALLY helps you understand the shortcomings and limitations of your own brain like few other things will.

If we all agree that minds are simply the physical result of brain-states and not some mysterious, ontologically basic 'second substance', then it seems to follow that a mind can be constrained or limited in the same way that any other physical system is constrained or limited.

Imagine that someone is stuck down a well, and you lower a rope to pull them out. If you hear them shout up from the bottom of the well, "my hands are broken, I can't grab the rope", you will not immediately roll your eyes and talk about how having broken hands makes them stupid and selfish and how dare they refuse your help.

Imagine that someone is stuck in the depths of suicidal depression, and you hand them a trivially simple thing that they could do to fix it (say, going to a doctor and picking up a $5 perscription for Paxil). If you hear them shout from the depths of their depression, "my mind is broken, and I can't implement your solution", how inclined are you to roll your eyes and talk about how being suicidal makes them stupid and selfish and how dare they refuse your help?

Over the past 10 years, there have been several easy solutions that I "could have" trivially implemented to end my depression, if only I wasn't so damned depressed.

If you know someone like this, and are so damned sure that there's a way out, implement it for them. Because if it's right in front of them, and they aren't implementing it, I GUARANTEE something other than "their own stupid damn fault" is keeping them from implementing it themselves.

And if you can't implement it for them either, then maybe you owe them AND yourself an explanation for why you think that solution is "right in front of them" in the first place.