CONCEPT, CLASSIFICATION AND CLINICAL DIFFERENTIATION OF NEGATIVE SYMPTOMS IN SCHIZOPHRENIA

Abstract

The negative symptoms of schizophrenia include volitional (motivational) (avolution, anhedonia and social isolation) and emotional (alogia and blunted affect) disorders. Negative symptoms worsen patient quality of life and functioning. From a diagnostic point of view, it is important to distinguish between primary as an integral part of schizophrenia and secondary negative symptoms as a result of positive symptoms, comorbid depression, side effects of antipsychotics, substance abuse or social isolation. The different trajectories of primary and secondary negative symptoms during the course of schizophrenia are proposed as an important discriminating factor. Clinical aspects of negative symptoms in schizophrenia, their definition, phenomenology, factor structure and classification are discussed. The historical and modern concepts of the paradigm of positive and negative disorders in schizophrenia and the likely pathophysiological mechanisms of negative symptoms are presented. In a comparative aspect, registration tools and psychometric assessment of negative symptoms are described in detail.