I'll take a stab at this. I know countless people who have struggled through severe depression and or suicidal thoughts. Some have even go to the extent to actually commit suicide, but I'd rather not speak on that. I've also experienced various degrees of depression in my life, but not to the degree of some of my friends and people I've met.
Us guys here in Oblivion actually had a long discussion about this topic, although it was more just talking about our experiences/our friends experiences with it. but for the sake of what you'd like to discuss, I won't go into any farther detail.
Is Suicide an ethical option?: I don't think suicide would be what some would call "ethical", but I do believe it can be truely necessary (I'm using this word somewhat reluctantly) in some situations, and the decision would be up to the person experiencing these problems. The thing is, in the worst cases, usually the person contemplating suicide doesn't have some place/somewhere to go. So it's quite simply pretty silly to discuss what they do, because there is nothing we can change about that sadly.
Is suicide selfish?: No. But I agree with what Kitten stated on that matter. This is the common thought from people who have no experience with severe depression.
I'm sorry to hear about all of that monkey, I'm glad you got the help you needed. And Deak, I see your point, but some of those statements you made were offensive and unnecessary. In fact, there are many, many very intelligent people(More intelligent than yourself, no matter how ridiculous that may seem) who contemplate or commit suicide, and some of the issue even becomes a matter of an existential crisis. I know this from speaking to a couple close friends of mine.
I would go more in depth, but I'm quite tired and need to get some rest.