Procedural validity of standardized symptom questions for the assessment of psychotic symptoms--a comparison of the DIS with two clinical methods.

The study examines to what degree well-documented present and life-time psychotic symptoms in a group of former psychiatric inpatients are ascertained when using the Diagnostic Interview Schedule (DIS). The Inpatient Multidimensional Psychiatric Scale (IMPS) and the Manual for the Assessment and Documentation of Psychopathology/Diagnostische Sichtlochkartei (AMDP/DiaSika) Interview-Checklist approach were used for the "clinical" evaluations of symptoms. The results indicate fair concordance between the two clinical approaches and the DIS with regard to the presence of any delusional or hallucination symptoms. Low to poor agreement was found in the assessment of many of the rather specific hallucinations and delusions. Generally, the concordance found was higher when compared to the more clinical AMDP/DiaSiKa approach than to the IMPS. More detailed comparisons with diagnostic subgroups of schizophrenic and schizoaffective patients substantiated the findings in the overall sample. Overall it was reconfirmed that the DIS approach is limited to those patients who are cooperative and at least partly remitted.