Comparison of clinical and best-estimate research DSM-IV diagnoses in a Finnish sample of first-admission psychosis and severe affective disorder

The purpose of this study was to investigate diagnostic agreement between c linicians and a research group in a sample of first-admission psychosis and severe affective disorder patients. Clinical DSM-TV discharge diagnoses an d best-estimate DSM-IV research diagnoses were compared in 116 first-episod e patients in the city of Turku, Finland. The best-estimate research diagno ses were made at consensus meetings by integrating longitudinal data; patie nts' medical records; and findings of a clinical interview, the structured SCAN-interview, and symptom severity ratings. Overall diagnostic agreement was moderate, with a kappa value 0.51 (95% confidence interval (CI), 0.39-0 .63). Of the diagnostic groups, schizophrenic disorders had the lowest kapp a value of 0.44 (95% CI, 0.26-0.63). Clinicians had a tendency to miss depr essive symptoms in psychotic patients; to overdiagnose psychotic symptoms i n depressive patients; and to fail to discover earlier hypomanic or depress ive episodes in depressive patients. In conclusion, hospital diagnoses were not reliable in first-episode patients. Inappropriate diagnoses may compro mise both treatment and epidemiologic findings based on discharge diagnoses .