I've often wondered if a tendency to suicide is genetic. In a village not far from my own, in Norfolk UK, a lovely lady whom I knew well, found her husband hanged in their garage. Two weeks later, their son, aged 22, did the same thing, leaving a young, pregnant wife. THEN we heard that the grandfather had taken his own life a few years before. Three generations, all by hanging. And in each case there was no sign of depression or distress. Maybe in the future, medical tests will check on young people's state of mind biochemically, and perhaps these abnormalities will be rectified with medication and monitoring.
I do feel that social isolation (eg if both parents are out at work and too tired to engage with their children) is a factor, as you suggest kendall.