The diagnosis of psychosis is based on the presence or absence of characteristic symptoms. The presence of such symptoms varies during the course and treatment, raising the question of diagnostic stability after a first psychotic episode.

The aim of this study is to evaluate the diagnostic stability after a first psychotic episode in the long term (five years after the first inpatient admission).

A retrospective study that included patients with first psychotic episode between 2007 and 2011 admitted to the inpatient unit of the psychiatry and mental health clinic of São João hospital center, Oporto, Portugal and re-evaluation of the diagnosis after five years.

We included 60 patients with a first psychosis episode, 22 of which were drop-outs after five years. Of the 38 patients evaluated, it was possible to see that after 5 years 68.4% (n = 26) maintained the same diagnosis during follow-up. In particular, the diagnosis of schizophrenia was kept in 83.3% of patients after 5 years (n = 15, 18 patients with the diagnosis of schizophrenia after first admission). Diagnosis of acute and transient psychotic disorder and psychosis not otherwise specified were the least stable diagnosis after 5 years.

The diagnosis after a first psychotic episode has important therapeutic and prognostic implications. The presence of characteristic symptomatology, with periods of partial or total remission between subsequent episodes emphasizes the need for regular monitoring, since this group of patients appears to be more vulnerable to changes in diagnosis over time.

The authors have not supplied their declaration of competing interest.