Objectives: Diagnostic shifts in first episode psychosis (FEP) are not uncommon. Many studies examining diagnostic stability use structured diagnostic interviews. Less is known about the stability of FEP diagnoses made clinically.
Methods: We conducted a retrospective chart review of patients enrolled in a transdiagnostic FEP clinic. For the 96 patients followed clinically at least 2 years, we compared diagnoses at intake and 24 months.
Results: Diagnostic stability was high for bipolar disorder (89%), schizoaffective disorder (89%), and schizophrenia (82%). Psychosis not otherwise specified (13%) was more unstable, with limited baseline differences that would enable clinicians to predict who would convert to a primary psychotic vs affective psychotic disorder.
Conclusions: Our real-world clinical sample shows that FEP diagnoses, with the exception of unspecified psychosis, are diagnostically stable, even without structured diagnostic interviews.
Keywords: diagnostic change; diagnostic stability; first episode psychosis; psychosis NOS; schizophrenia.
© 2020 John Wiley & Sons Australia, Ltd.