Psychopharmacology and the Classification of Functional Psychoses
By Thomas A. Ban and Bertalan Petho
Classification and Clinical Psychopharmacology
ICD-9
Well before the changes brought about by psychopharmacologic progress had crystallized, experts from 35 countries participated in a World Health Organization program on the standardization of psychiatric diagnosis, classification and statistics. Their review of the state of affairs resulted in the glossary of mental disorders, which was distributed as a companion to the 8th edition of the International Classification of Diseases (ICD-8). The same glossary, with some modification was incorporated in Chapter V of the 9th edition of the ICD (ICD-9) completed in 1975 and published in 1977 (Jablensky et al., 1983).
The mental disorders section of ICD-9 is primarily directed to fulfill the needs of epidemiological research and is firmly rooted in a traditional framework of psychiatric classification. It is based on the separation of "psychoses" from "neuroses" (personality disorders and other non-psychotic mental disorders) and on the dichotomy between organic psychotic conditions and other psychoses. Disorders subsumed under "other psychoses" in the ICD-9 are commonly referred to as functional psychoses, implying the absence of organicity.
Functional psychoses in the ICD-9 are divided into three endogenous and one reactive group of disorders. (It should be noted, however, that the terms "functional," "endogenous" and "reactive" are not used in the ICD-9.) The three endogenous groups of disorders are schizophrenic psychoses (including acute schizophrenic episode; latent and residual schizophrenia; and simple, hebephrenic, catatonic, paranoid and schizoaffective types of schizophrenia); affective psychoses (including manic- depressive psychosis manic, depressed and circular types); and paranoid states (including paranoia, paraphrenia, induced psychosis and paranoid state simple type). The reactive group, referred to as other nonorganic psychoses, includes reactive confusion, acute paranoid reaction, psychogenic paranoid psychosis and other nonorganic psychosis depressive and excitative types (see Appendix III, Table I).
To update the ICD-9, a major International Conference on Diagnosis and Classification was convened in Copenhagen in 1982. Participants in this conference agreed that among the factors contributing to the revival of interest in psychiatric diagnosis were the advances in pharmacological treatment which require more refined diagnostic assessment; and the advances of biological research towards an understanding of the causal mechanisms underlying some of the major mental disorders. Other contributing factors considered were the attractions of new tools such as, standardized instruments for diagnostic interviewing, operationalized diagnostic criteria and experiments with multi-axial recording systems.
No consensus was reached at the Copenhagen conference regarding a theory underlying the classification of mental disorders. Some participants expressed the view that disease entities in psychiatry are not intrinsically different from disease entities in general medicine with specific causes, symptoms, course, outcome (corresponding with the original contention of nosological theory) and response to treatment. At the same time, other participants maintained that the phenomenology of mental disorders seems to reflect etiologically non-specific responses of the personality to neurochemical events or altered cerebral structures. However, there was a widely shared contention that distinctions like those between "organic" and "functional," or "endogenous" and "exogenous," or "psychosis" and "neurosis" were at least questionable and needed revision or at least qualification (Jablensky et al., 1983).
Regarding "functional psychoses" it was agreed that the designation of these disorders as such is misleading because "organic" features might be present in presumably "functional conditions" and because many of the syndromes within this category do not exhibit the features corresponding to the traditional notion of "psychosis." The participants agreed that the extensive clinical and genetic evidence for schizophrenia made it a valid and useful concept. It is a disorder, or a group of disorders, for which a predisposition is genetically transmitted and which is of worldwide occurrence. The same applies to manic and depressive illnesses. There is both clinical and genetic evidence for a distinction between unipolar and bipolar affective disorders.
It was also agreed that there are good reasons to classify patients with "schizoaffective" symptoms separately from both the schizophrenic and the affective categories. There are acute psychoses of brief duration which obviously do not belong to either the schizophrenic or the affective diagnostic groups; and there is a variety of paranoid and other delusional states which tend to occur with a peak frequency in middle age or late middle age (Jablensky et al., 1983).
As a follow up of the Copenhagen Conference the Division of Mental Health of WHO held an informal consultation at which proposals for the classification of mental disorders and psychosocial factors in the ICD-10 were discussed. The ICD-10 is planned to be completed by 1990 and implemented in 1992 or 1993. If the present outline is accepted, the conditions traditionally subsumed under "functional psychoses" will be included under the headings of schizophrenic and related disorders and mood (affective) disorders. Subsumed under the heading of schizophrenic and related disorders will be schizophrenia (paranoid, hebephrenic, catatonic, undifferentiated, and residual and postschizophrenic depression); schizophrenic spectrum disorders (schizotypal personality disorder and simple schizophrenia); persistent delusional disorders (paranoia and monosymptomatic, induced and other persistent delusional disorders); acute and transient psychotic disorders (acute delusional episode, cycloid psychosis, psychogenic delusional disorder, acute dissociative-confusional episode, acute schizophreniform episode and other acute psychotic disorder); and other non-organic psychotic disorders. Subsumed under the heading of mood (affective) disorders will be bipolar affective disorder (currently manic, depressive, mixed or in remission); recurrent depressive disorder (severe and mild); depressive episode (severe and mild); other affective disorder; schizoaffective disorder (schizomanic and schizodepressive); and chronic affective states (cyclothymia and dysthymia) (Report on Informal Consultation, 1984).