Stability of diagnosis in schizophrenia

OBJECTIVE: The authors investigated factors associated with change in diagnosis from schizophrenia to other disorders and from other disorders to schizophrenia, as well as the time elapsed before diagnostic change. METHODS: Using a longitudinal study design, they examined data collected over a 7-year period at an urban acute care psychiatric hospital. The subjects were 936 inpatients who had been hospitalized at least four times during the study period. Changes to and from a diagnosis of schizophrenia over the 7 years were investigated in relation to demographic variables, socioeconomic factors, and clinical features. RESULTS: Fifty-six (21.9%) of the 256 subjects with a diagnosis of schizophrenia at the beginning of the study received a different diagnosis during a subsequent hospitalization. Females and subjects of Hispanic origin were more likely to undergo a diagnostic change from schizophrenia. Two hundred twenty-three (32.8%) of the 680 subjects who initially had a diagnosis other than schizophrenia were later diagnosed with schizophrenia. Males and African Americans had significantly higher rates of change to a diagnosis of schizophrenia than females and other ethnic groups. In addition, socio-economic factors and clinical features were associated with a change in diagnosis from another disorder to schizophrenia. CONCLUSIONS: The diagnosis of schizophrenia, in current practice, is not static. Patients' characteristics interact with longitudinal clinical changes to produce shifts in diagnosis. Longitudinal follow-up is necessary to validate diagnoses.