Traumatic life events and psychiatric morbidity are associated in a complex manner. Only a minority of those who are exposed to traumatic events will develop a psychiatric disorder. Thus, an individual sensitivity exists. Recently, considerable knowledge has evolved about the complex molecular, anatomical and genetic factors that interact when people are exposed to traumatic events and develop a psychiatric disorder. In several studies there is a focus on the neurobiological consequences of childhood trauma and its relation to the development of psychopathology. Current knowledge is reviewed.