Deficit of the theory-of-mind in schizophrenia: clinical concept and review of experimental arguments

This article synthesizes and discusses the clinical and experimental arguments for applying the concept of a theory-of-mind deficit to schizophrenia. The term "theory of mind" is defined. A review of literature on the hypothesis of a theory-of-mind deficit in schizophrenia is then presented. Clinical and experimental arguments are discussed. The article concludes with a summary of the issue. The hypothesis of a theory-of-mind deficit in schizophrenia is convincing, particularly considering the most recent experimental evidence. This cognitive deficit explains the presence of schizophrenia symptoms such as delusions of influence and reference, problems in social adaptation, and signs of disorganized communication. Consideration is given to the roles played by situational ambiguity, the individual's intellectual level, and type of treatment. The hypothesis of a theory-of-mind deficit has only recently been applied in schizophrenia research; it may have a strong impact on clinical practice. If its role in the onset of symptoms is to be better understood, explanatory models and experimental paradigms must be further refined.