[Psychosocial factors of depressive risk]

The influence of psychosocial factors on the incidence and evolution of depressive illness is well established. The joint study of different aspects of the psychosocial field involved in the risk of depressive illness substantiated interactions between these various factors, modulating the risk of depression. Several psychosocial models of depression, as Harris and Brown's model, have taken into account those interactions, discriminating vulnerability factors and precipitating factors (stressful life events, lasting difficulties): vulnerability factors, not inducing depression per se, increase the depressing effect of precipitating factors when both factors happen to be combined. However the validity of those models has to be confirmed, and mechanisms underlying interactions between psychosocial factors call for further elucidation. Other studies will also have to specify the role of psychological and biological variables in the way psychosocial factors interfere with the occurrence of depression.