9 December 2005, EMBL Monterotondo (Rome)

Hazard, heredity and depression

Peter McGuffin, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London

Although there is a great deal of support for the common sense view that depression is often associated with unpleasant events, there is also consistent evidence that depression runs in families and is substantially genetic. There is also considerable evidence from studies of families and twins that life events are not completely randomly distributed in the population. Some individuals are more prone to life events than others and some are more susceptible to the depressing effects of unpleasant happenings. These phenomena probably reflect gene-environment covariation and interaction and, together with the fact that depression shows a complex polygenic pattern of transmission, make the task of locating and identifying genes difficult. Nevertheless some interesting findings are emerging from linkage studies and one of the genes that are involved in depressive or anxious response to stress has now almost certainly been identified.