Biomarkers hold immense promise for the early detection of disease. Unlike other disorders like diabetes and heart disease where a limited number of biological markers are at hand that allow the physician to come up with a reliable diagnosis, there are currently no such markers available for affective disorders. As in any other disease area a major goal is therefore the identification of early markers that can categorize subsets of subjects in a consistent manner. This will allow a more precise definition and categorization of affective disorders and in turn facilitate investigations of...