over the edge

what provokes someone to go over the edge?  i guess we all have it in us to go this way –but most of us never push that button.  but some do and do so with major repercussions.  oftentimes it stems from depression.  we get depressed –but not for a day –for many days, for weeks, for months –and this drives us over the edge.  it could drive us to take our own life or someone else’s.  it is so bizarre to see someone go this way –to see this bizarre behavior –to see that this is not a person that we all knew –to see that they act very strangely in their final acts –to see them act so methodically in deciding that they wish to die –either due to loneliness or to physical pain or to stress from work or to pressure from family or to financial strain.  we all go through life following a routine that keeps us on the path –that keeps us from going over the edge.  then 1 day, change occurs –like it has in the past –but this time you cannot adapt as you have done before –this time you fall off the path and cannot get back on–this time your mind is altered and then you move from “he was always very calm and nice” to “why did he do that, why did he take his own life” –very bizarre –but seen over and over in life.  we need routine, we need habits, we need stability to keep from going over the edge.  because when you do go over the edge and take your life –it is the people who are left that feel the most pain.  but you don’t care like you used to –you don’t care what people say or how they find you –you don’t care anymore.  you might think you are helping those left behind, but you are not.  you have just gone off this path that you try to keep on from the beginning –you can’t get back on–you can’t get those happy innocent days of the past –you see fewer answers –eventually leading to a bizarre choice and a bizarre ending.  but why? ( not the clinical or psychological answer) –just why?