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.