McLean-Harvard International First-Episode Project: Two-Year Stability of DSM-IV Diagnoses in 500 First-Episode Psychotic Disorder Patients

Objective: Since stability of DSM-IV diagnoses of disorders with psychotic features requires validation, we evaluated psychotic patients followed systematically in the McLean-Harvard International First Episode Project.

Method: We diagnosed 517 patients hospitalized in a first psychotic illness by SCID-based criteria at baseline and at 24 months to assess stability of specific DSM-IV diagnoses.

Results: Among 500 patients (96.7%) completing the study, diagnoses remained stable in 77.6%, ranking as follows: bipolar I disorder (96.5%) > schizophrenia (75.0%) > delusional disorder (72.7%) > major depressive disorder (MDD), severe, with psychotic features (70.1%) > brief psychotic disorder (61.1%) > psychotic disorder not otherwise specified (NOS) (51.5%)>> schizophreniform disorder (10.5%). Most changed diagnoses (22.4% of patients) were to schizoaffective disorder (53.6% of changes in 12.0% of subjects, from psychotic disorder NOS > schizophrenia > schizophreniform disorder = bipolar I disorder most recent episode mixed, severe, with psychotic features > MDD, severe, with psychotic features > delusional disorder > brief psychotic disorder > bipolar I disorder most recent episode manic, severe, with psychotic features). Second most changed diagnoses were to bipolar I disorder (25.9% of changes, 5.8% of subjects, from MDD, severe, with psychotic features > psychotic disorder NOS > brief psychotic disorder > schizophreniform disorder). Third most changed diagnoses were to schizophrenia (12.5% of changes, 2.8% of subjects, from schizophreniform disorder > psychotic disorder NOS > brief psychotic disorder = delusional disorder = MDD, severe, with psychotic features). These 3 categories accounted for 92.0% of changes. By logistic regression, diagnostic change was associated with nonaffective psychosis > auditory hallucinations > youth > male sex > gradual onset.

Conclusion: Bipolar I disorder and schizophrenia were more stable diagnoses than delusional disorder or MDD, severe, with psychotic features, and much more than brief psychotic disorder, psychotic-disorder NOS, or schizophreniform disorder. Diagnostic changes mainly involved emergence of affective symptoms and were predicted by several premorbid factors. The findings have implications for revisions of DSM and ICD.