The Classification of Functional Psychoses and its Implications for Prognosis

Abstract
One hundred and eighty-three patients suffering from functional psychoses were diagnosed according to ICD–8, RDC, and DSM–III criteria, and the concordance rates for the diagnoses compared. The heterogeneity of the diagnosis 'schizoaffective psychosis' as defined by these systems became clear. With respect to prognosis, the DSM–III diagnosis of schizophrenia was most closely related to poor outcome. Affective psychoses and schizoaffective psychoses, as well as DSM–III 'schizophreniform disorders', demonstrated a favourable prognosis.