[Basic symptoms in schizophrenia, their clinical study and relevance in research]

Basic symptoms consist of subtle sub-clinical disturbances subjectively experienced by schizophrenia patients. These are mainly related to drive, affect, thinking and language, perception, memory, motor action, central vegetative functions, control of cognitive processes, and stress tolerance. Initially described by Huber, from a phenomenological approach, basic symptoms are part of the earliest features of schizophrenia, and they can evolve along the course of the disorder. Their assessment during the prodromal phase of the disease (together with ultra-high risk criteria) is one of the 2 main approaches that allow the definition of states of clinical risk for the development of psychosis. The present review provides an updated view of the concept of basic symptoms, highlighting its potential value in establishing neurobiological correlates of interest in aetiopathogenic research.