Subjective experience of schizophrenia.

A standardized assessment of the subjective experience of schizophrenia and depression was developed in three stages: (1) An open-ended interview covering changes in nine areas of psychological functioning was given to acute, remitted, and chronic schizophrenic patients, and to depressed patients. (2) On the basis of their replies, a structured interview was given on two separate occasions close in time to 20 remitted schizophrenic patients by two different interviewers to test interrater reliability, and to the same 20 remitted patients 6 months later by one interviewer to test intertemporal reliability. (3) The most reliable items were retained in a final version, from which the replies of a new group of 20 remitted depressed and the 20 remitted schizophrenic patients could be compared. Despite the long interval that usually had elapsed between the first episode of illness and the time of questioning, most patients gave a detailed account of their experiences that did not vary much either 6 months later or in an interview by a different psychiatrist. The most reliable items concerned changes in perception, and these also best distinguished the experiences of schizophrenia from those of depression. Perceptual dysfunction appears to be the most invariant feature of the early stage of schizophrenia, but a qualitative disturbance of thinking also occurs.