Is schizophrenia disappearing? The rise and fall of the diagnosis of functional psychoses: an essay.

BACKGROUND: The categories of functional psychoses build on views of influential professionals. There have long been four main categories - affective, schizophrenic, schizoaffective/cycloid/reactive/polymorphic, and delusional/paranoid psychoses. The last three are included in "psychotic disorders". However, this dichotomy and the distinctions between categories may have been over-estimated and contributed to lack of progress.

TEN TOPICS RELEVANT FOR THE DIAGNOSIS OF FUNCTIONAL PSYCHOSES: 1. The categories of functional psychoses have varied with time, place and professionals' views, with moving boundaries, especially between schizophrenia and affective psychoses. 2. Catatonia is most often related to affective and organic psychoses, and paranoia is related to grandiosity and guilt, calling in question catatonic and paranoid schizophrenia. Arguments exist for schizophrenia being a "misdiagnosis". 3. In some countries schizophrenia has been renamed, with positive consequences. 4. The doctrine of "unitary psychosis", which included abnormal affect, was left in the second half of the 1800s. 5. This was followed by a dichotomy between schizophrenia and affective psychoses and broadening of the schizophrenia concept, whereas affective symptoms were strongly downgraded. 6. Many homogeneous psychoses with mixtures of schizophrenic and affective symptoms were described and related to "psychotic disorders", although they might as well be affective disorders. 7. Critique of the extensive schizophrenia concept led to, in DSM-III and ICD-10, affective symptoms being exclusion criteria for schizophrenia and acceptance of mood-incongruent psychotic symptoms in affective psychoses. 8. However, affective symptoms are often difficult to acknowledge, diagnosis is often done on the basis of tradition and previous education, and patients' affect characterized accordingly. 9. DSM-5 is up-dated with separate chapters for catatonia and psychotic symptoms, and removal of the subtypes of schizophrenia. However, time may be running out for categorical psychosis diagnoses, which may be replaced by continuum, spectrum, dimensional and research domain criteria, in line with new biological data 10. This is supported by treatment responses across categories.

CONCLUSION: The time-consuming works on diagnosis of psychoses may have hampered progress. Chronic mood disorders may appear as schizophrenic or paranoid psychosis, end-stages like heart failure in heart diseases. This underscores the importance of early and optimal treatment of mood disorders.