This is a question that is very close to me, and which I've been chewing over for the better part of a decade. I have had a close personal friend for many years with a history of mental illness; having watched their decline over time, I found myself asking this question. From a purely rational standpoint, there are many different functions that you can use calculate the value of suicide versus life. As long as you don't treat life as a sacred/infinite value ("stay alive at all costs"), you can get answers for this.

My problem is that a few years ago, I started noticing measures that were pro-suicide. As quality of life and situation declined, more and more measures flipped that direction. What do you do as an outside observer when most common value judgements all seem to point toward suicide as the best option?

It's not like I prefer this answer. What I want is for the person in question get their life together and use their (impressive) potential to live a happy, full life; what I want is another awesome person making the world we live in even more awesome. Instead, there is a person who as near as I can estimate actually contributes negative value when measured by most commonly accepted goals.

How much is the tradeoff worth? If I sacrifice the remainder of my rather productive life in an attempt to 'save' this person, have I done the right thing? I cannot in good conscience say yes.

These are obnoxious problems.

"If a person's life really isn't worth living [objectively]" then the person should stop caring about flawed concepts like objective value. "If a person's life really isn't worth living [subjectively]" then they should work on changing their subjective values or changing the way that their life is so it is subjectively worth living. If neither of the above is possible, then they should kill themselves.

It's important that we recognize where the worth "comes from" as a potential solution to the problem.

This insight brought to you by my understanding of Friedrich Nietzsche. (Read his stuff!)

They don't "have" to keep going but striving for better is a more optimistic encouragement is it not? I would rather teach someone that they have worth rather than tell them that suicide (Which will undoubtedly have negative effects on their family if they have a family that loves them) is what I want for them too.

Agreed in substance, but I disapprove of your phrasing "seriously lame comment" and downvoted for that.

That shows no evidence that would support the fact that it's an efficient mentality one should willingly accept. Obviously nature is trying everything it can to preserve the life it has created. You wish to go against the will of life's plan for preservation.