Epigenetics is the study if how people’s experiences and the environment affects the function of our genes. This would be the science of nature /nurture. It seems what happens in the womb and after can affect the development of mental illness. Epigenetics is an exciting field. Hopefully it will lead to new therapies and a better understanding of a pre-disposition to a mental illness.
I have chosen an article from the New York Times to help you learn about this new science. It is an easy read and has links to other articles.