Classification of functional psychoses and its implication for prognosis: Comparison between ICD-10 and DSM-IV

Background: The aim was to examine the agreement and differences
between ICD-10 and DSM-IV in the classification of functional
psychoses. Sampling and Methods: In a sample of 218
first-hospitalised patients, ICD-10 diagnoses were compared with
DSM-IV diagnoses. Functional psychoses of both diagnostic systems
were classified into the four diagnostic groups schizophrenia,
transient/episodic psychoses, delusional disorders and affective
disorders. Based on information from a 15-year follow-up, it was
examined which course is associated with each diagnostic group.
Results: Although in ICD-10 there was a higher frequency of
schizophrenia and a lower one of affective disorders, a high
agreement between ICD-10 and DSM-IV (kappa value of 0.82) was
found. In both diagnostic systems, transient/episodic psychoses and
affective disorders were mainly associated with a non-chronic
course and schizophrenia was mainly associated with a chronic one.
Nevertheless, several patients with transient/episodic psychoses
showed a chronic course (ICD-10: 10%, DSM-IV: 15%) and more than
one third of patients with schizophrenia a non-chronic one (ICD-10:
40%, DSM-IV: 33%). Conclusions: In the cross-sectional assessment,
there is a high diagnostic agreement between ICD-10 and DSM-IV.
With respect to the long-term course, the delimitation of
transient/episodic psychoses from schizophrenia was neither
completely achieved by ICD-10 nor by DSM-IV. Copyright (C) 2004 S.
Karger AG, Basel.