Fifty years ago depression, schizophrenia and many other psychiatric disorders were often attributed solely to one's present or past environment: one's upbringing, one's parents, early childhood experiences, alcohol, drugs etc. And while such factors continue to play a critical role, it is now accepted that many of these conditions also have an underlying genetic component. Furthermore, recent advances in genetics suggest that many human genes are replications of those found in fruit flies, worms, mice and our nearest primate relatives.