Abstract: | The diagnosis of schizophrenia is made on the basis of a diverse set of characteristic signs and symptoms. These include disturbances in perception and inference, abnormalities in communication, behaviour and motor activity, and deficits in emotional expressivity, hedonic capacity and drive. No single symptom or set of symptoms is pathognomonic, and the question of which symptoms are indeed at the ‘core’ of schizophrenia has been an issue of much debate, opinion and study since the disorder was first described a century ago. In this review, the symptoms emphasized in current diagnostic criteria for schizophrenia are described and the relative importance of these symptoms in the evolution of the schizophrenia construct is discussed. |