It sounds as if there were many possible reasons for the schizophrenia prevalent in the Galvin family without having to even suspect a genetic cause. I also am convinced there is no strong genetic component to mental illness (meaning no specific gene or genes). However, I do believe that some people are more fragile and more vulnerable to adverse life events than others. Of course, I could be wrong. I base this simply on my own observations, not on any scientific study. I observed, for example, one person become schizophrenic over a possible divorce, while most people don’t react that way. I know someone who was at the Twin Towers on 9/11 who had a schizophrenic breakdown. Most people, though extremely distressed, didn’t. So heredity, who we are, may play a role in the development of mental illness. It could be argued that there are environmental reasons for vulnerability and undoubtedly there are, but does experience trump heredity. We just don’t know. There are probably very complex interactions.