The iowa structured psychiatric interview. Rationale, reliability, and validity.

The Iowa Structured Psychiatric Interview (ISPI) is an interview form designed for psychiatric epidemiological research in the general population. Its use provides detailed information about important aspects of psychiatric, social, and family history. Detailed information is gathered about the frequency and duration of symptoms that characterize schizophrenia, mania, depression, and neurosis. The instrument is also designed to be administered by well-trained nonmedical personnel in order to facilitate its utilization in large-scale field studies. Such interviewers are assumed to be blind to the study status of the informants, and the format of the ISPI maintains that blindness throughout crucial sections of the interview. In addition, the ISPI can be used without any implication that the informant or the informant's relatives have any type of psychiatric history or current psychiatric problems. This monograph discusses the rationale for the ISPI and gives a formative history of the instrument. We also present the results of studies investigating the reliability and validity of a set of twenty screening questions for schizophrenia, mania, depression, and neurosis - items which form the nucleus of the ISPI. The excellent reliability of these items is contrasted with the relatively poor reliability of a set of behavior ratings included in the ISPI. The ISPI itself is given in full in an appendix, along with detailed guidelines for use and suggestions for selecting and training personnel to administer the ISPI in the field. We hope that the ISPI can be further tested by other researchers in psychiatric epidemiology.