Yes, I have lost my brother and having gone through that I could not bring myself to put my family through another death. I am sure at least one of them would have killed themselves as a result and even if they didnt it would put them into an even more unimaginable hell.
Of course, once I realized the amazing potential of meds I have never had any real serious thoughts of suicide. It is so, so, so sad that some people never get the chance to realize that technology actually does exist to alter our brain chemistry to suddenly feel happy and actually allow us to be ourselves. I was lucky enough to stumble upon the potential of meds when I was put on adderall for declining grades that were thought to be related to ADD, which they were in a small part (of course my blatant suicidal depression didn't bother my parents a damn bit all the years before this but one slip up in grades and everybody freaks out... sheesh, just goes to show the moral immaturity of our society's mainstream culture).
You are right that depression does completely brainwash you. We are not ourselves at all when we are severely depressed. All of our individuality and life is literally drowned in a sea of debilitating, blinding negative emotion. This is a quite close to literal metaphor in terms of how our brains operate when bombarded with excessive emotion, they can't even process much anything else and hence our identity is lost in the sadness.
There is hope though. I can't begin to describe how much more horribly difficult it was to survive day to day when I had no idea that there actually was such tremendous hope in the form of modern life saving treatments for mental disorders.