Stability of diagnoses in various psychiatric disorders: a study of long-term course

The frequency of diagnostic shift was investigated in 267 patients diagnosed with various psychiatric disorders according to the 9th revision of the International Classification of Diseases (ICD-9). Forty-six patients fulfilled the diagnostic criteria for schizophrenic psychosis, 71 for affective psychosis, 66 for neurotic disorder, 24 for personality disorder, and 40 for psychogenic reaction. The remaining 20 patients were diagnosed with heterogenous disorders. The mean follow-up time was 12.5 years. Every episode of inpatient treatment was diagnosed cross-sectionally. Patients with an initial episode of schizophrenic psychosis showed by far the greatest stability (93%). A high stability was found in patients diagnosed with neurotic disorders (79%). Forty-two patients with an index diagnosis of affective psychosis suffered more than one type of episode during the course of disease. The lowest stability was noted in patients with a psychogenic reaction (10%). Eleven percent of patients with a final diagnosis of schizophrenia had an index diagnosis of psychogenic reaction. Our findings demonstrate that the course of disease should be considered in making the final diagnosis.