Diagnostic stability of first-episode psychosis and predictors of diagnostic shift from non-affective psychosis to bipolar disorder: a retrospective evaluation after recurrence.

Diagnostic changes during follow-up are not uncommon with a first-episode psychosis (FEP). This study aimed to evaluate the diagnostic stability of the FEP and to identify factors associated with a diagnostic shift from non-affective psychosis to bipolar disorder. Considering that the diagnosis of FEP is frequently more definite after recurrence in many clinical settings, a retrospective evaluation after recurrence was preformed. Subjects were 150 patients with psychotic disorders who had been admitted to a psychiatric ward both for first episode and recurrence of their psychosis. Consensus diagnosis was made for each episode through a review of hospital records. Patients diagnosed with non-affective psychoses at the first episode were included in the analysis of predictive factors of a diagnostic shift to bipolar disorder. First-episode diagnoses were revised upon recurrence in 20.7% of patients. The most common change was to bipolar disorder accounting for more than half of all diagnostic changes. Schizophrenia exhibited the highest prospective and retrospective diagnostic consistencies. Female gender, short duration of untreated psychosis, high level of premorbid functioning, and several symptoms including lability, mood elation, hyperactivity, and delusions with religious or grandiose nature were identified as predictive factors for a diagnostic shift from non-affective psychosis to bipolar disorder. Clinical features of psychoses seem to evolve during the disease course resulting in diagnostic changes upon recurrence in a significant portion of FEP. Special consideration on a diagnostic shift to bipolar disorder is required in patients exhibiting the predictive factors identified in the current study.