Stability of schizophrenia diagnosis in a 10-year longitudinal study on first episode of non-affective psychosis: Conclusions from the PAFIP cohort

Objective To evaluate the 10-year stability of schizophrenia diagnosis in a cohort of first-episode psychosis (FEP) patients and the factors associated with it. Methods Changes in diagnosis of 209 FEP patients were described during 10 years of follow-up. Related factors with maintenance or change of schizophrenia diagnosis were evaluated in prospective and retrospective approaches through binary logistic regressions, ROC and survival curves. Results Out of the 209 patients, 126 were diagnosed of schizophrenia 6 months after their inclusion in the clinical program. Prospective analyses showed that eight of those 126 schizophrenia patients had changed to a different diagnosis after 10 years, and predictors of change were better childhood premorbid adjustment, less severity of clinical global impression at baseline, and diagnosis of comorbid personality disorder during follow-up. Retrospectively, out of the 154 patients with schizophrenia in the 10-year assessment, 36 had a different diagnosis at baseline, and those factors related to a different prior diagnosis than schizophrenia were better socioeconomic status and shorter duration of untreated psychosis (DUP). A survival analysis on the timing of schizophrenia diagnosis showed that male gender and longer DUP were predictors of earlier definite diagnosis. Conclusions Diagnostic stability of schizophrenia in our FEP sample is high, especially prospective stability, and the group of patients with diagnostic change corresponded to a milder psychopathological profile before and at the onset of disease. Moreover, we observed a cautious attitude in the diagnosis of schizophrenia in patients with shorter DUP who had schizophrenia diagnosis after 10 years.