Self-reported psychotic experiences in the general population: a valid screening tool for DSM-III-R psychotic disorders?

Objective: To examine the diagnostic value of self-reported psychotic-like experiences for DSM-III-R psychotic disorders . Method: A general population sample of 7076 subjects aged 18-64 years was interviewed with the Composite International Diagnostic Interview (CIDI) and, if there was evidence of psychotic experiences, the Structured Clinical Interview for DSM-III-R. Results: The probability of having a psychotic disorder increased in a dose-response fashion with the level of self-reported psychotic experiences, but individual CIDI psychotic experience ratings had relatively low post-test probabilities (PPs) (range: 5.1-26.5%). However, limiting the sample to individuals who had been in contact with mental health services substantially improved PPs (range: 13.3-43.1%). Conclusion: Screening for psychosis in the population carries a high risk of stigmatization in false-positive cases and violation of the right 'not to know' in true-positive cases. However, in mental health care users, self-reported psychotic experiences may be a useful screening tool in individuals who have already developed help-seeking.