The Psychopathological Foundation of Insight in Schizophrenia

Summary

The description of psychiatry, especially that for schizophrenia, has been based upon two roots. One is to delineate the diagnostic contour of an illness, and the other is to clarify the content: in other words, extension versus intension-oriented description. The diagnostic concept of schizophrenia inherited from Kraepelin through Schneider to the current Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) belongs to the former, whereas the concept of psychosis proposed by Jaspers, which contains as its components the loss of insight together with incomprehensibility, belongs to the latter. Because the DSM-IV does not consider any discussion on the intension of a disease, the concept of psychosis or insight finds no place in this system. Nevertheless, the concept of insight still has considerable importance: first, it is still strongly held by psychiatric clinicians, as our study has demonstrated; second, it has a heuristic value for future research in the cognitive dysfunction in schizophrenia, in that insight is related to the self-monitoring function whose disturbance plays an essential role in schizophrenia.