This chapter argues that important contributions have been made by linking cognition, emotion and the social world with the emergence and maintenance of psychotic experiences. It discusses some of the consequences of the formulation of the concept of schizophrenia. Modern cognitive models of psychosis start by postulating continuities between psychosis and normal experience. There has been a prima facie assumption about aetiological theories in psychosis, a reductionist position placing genetic explanations at the beginning of the aetiological process. The study of single psychotic symptoms, or single types of symptom, is assisted by a clear account of the symptoms themselves. The association of stressful life events with relapse into positive symptoms is well established. The detailed study of the relationship between trauma and psychosis is in its early days, but the investigation of the emotional and cognitive processes common to trauma responses and to psychosis in the view carries considerable promise.