A COMPARISON OF CLINICAL AND RESEARCH DSM-III-R DIAGNOSES OF SCHIZOPHRENIA IN A FINNISH NATIONAL BIRTH COHORT - CLINICAL AND RESEARCH DIAGNOSES OF SCHIZOPHRENIA

As a prerequisite to the use of the Finnish National Hospital Discharg e Register in psychiatric epidemiological research, we studied the dia gnostic reliability of the register in terms of the psychiatric morbid ity experienced by a national birth cohort. We investigated all entrie s to the register for a sample based upon the Northern Finland 1966 bi rth cohort at the age of 16 years (n = 11017). Until the end of 1993 ( age 27 years), a total of 563 subjects had a register diagnosis indica ting a psychiatric illness, 37 of them being schizophrenia. When opera tional criteria (DSM-III-R) were applied to clinical information in th e available original hospital records for cases of psychosis, personal ity disorder and substance abuse(n = 249), 71 fulfilled criteria for s chizophrenia, including all of the 37 cases in the register and an add itional 34 (48% false-negatives), most frequently diagnosed in the reg ister as schizophreniform or other psychosis. Despite the official use of DSM-III-R nomenclature, it appears that the clinical concept of sc hizophrenia in Finland, manifest within the register, remains very res trictive. The application of operational criteria is a necessary prere quisite for scientific research on schizophrenia.