People who are interested in the interaction of genes, environment, brain and mental illness might be interested to look at a brief article posted over at the Psychiatric Resource Forum.
The article summarizes some very important new data on social adversity and the subsequent dvelopment of major mental illness. The research has been looking at a huge puzzle: why are serious mental illnesses so much more common in Afro-Caribbeans and Africans living in England and other parts of Western Europe? It was initially thought that it might all be due to over-diagnosis, but with deatialed work done in England, the Caribbean and Africa it has now become clear that that isn't it.
There may be a contribution from vitamin D deficiency: dark skinned people who are recent immigrants cannot make as much in their skin as they need. But that is not a cause but a potential contrbutor. That being said I am going to have something more to say about causality in medicine in a post in the next day or two.
A second line of research has identified some key brain structures that if abnormal, dramatically increase the change that a "high risk" person will develop schizophrenia. By "high risk" we mean a significant family history of the illness.
This is important material and represents a major step forward in our understanding of major mental illness and a move away from the medical model that has dominated so much of psychiatry over the last 30 years.