Mohammed T. Abou-Saleh

Principles and Practice of Geriatric Psychiatry.Editors: Professor John R. M. Copeland, Dr Mohammed T. Abou-Saleh and Professor Dan G. BlazerCopyright & 2002 John Wiley & Sons LtdPrint ISBN 0-471-98197-4 Online ISBN 0-470-84641-022Classification of Dementia and Other OrganicConditions in ICD-10A. Jablensky and J. E. CooperDepartment of Psychiatry and Behavioural Science, University of Western Australia, Perth, AustraliaThe classification of mental disorders in the Tenth Revision of theInternational Classification of Diseases (ICD-10) is different fromits predecessor, ICD-9, in several ways. In addition to a revisedcontent that reflects the most important recent advances inresearch and clinical practice, it is presented in different versionsfor different types of professional users. The differences are,however, in degrees of detail and the versions are compatible witheach other, since they are all derived from the same basic document(Clinical Descriptions and Diagnostic Guidelines, WHO, 1992) 1 .THE USES OF ICD-10ICD-10 has necessarily retained its historical purpose of facilitatingthe recording of national and international statistics ofmorbidity and mortality, but now has the added values of alsobeing designed as a uniquely international aide to clinical work,teaching and research. It achieves these objectives by means of anupdated list of diagnostic rubrics, a set of glossary-type definitionsof disorders and additional explicit diagnostic criteria. The latterhave been developed in two versions: (a) clinical diagnosticguidelines for routine use, allowing sufficient flexibility anddiscretion in the application of ‘‘clinical judgement’’ in thehospital ward or the outpatient service; and (b) diagnostic criteriafor research (ICD-10-DCR), providing stringent decision-makingrules to increase the specificity of diagnostic classification and thusensure a high level of sample homogeneity for the purposes ofclinical, biological and other research 2 .As a result of a great deal of collaboration between the advisersto the World Health Organization and the several Task Forcesthat assembled DSM-IV on behalf of the American PsychiatricAssociation during the last few years of the preparation of boththe classifications, there are very few important differencesbetween them. Since the same body of internationally publishedresearch experience and literature was available to both sets ofexperts during the processes of development, those differencesthat remain are mainly differences of opinion rather than of fact.Some differences reflect the need for ICD-10 to accommodate amuch broader base of international experience and opinions thana national classification. In the development of ICD-10, expertsfrom many different cultures and languages were involved fromthe earliest stages.As in ICD-9, Chapter V deals with ‘‘Mental and BehaviouralDisorders’’ and is intended for the recording of the clinicalsyndromes as presented and experienced by the patient. If aspecific underlying cause of the disorder is known (or highlyprobable), additional codes should also be used from otherchapters of ICD-10, such as: Chapter I, Infectious and ParasiticDiseases; Chapter II, Neoplasms; or Chapter VI, Diseases of theNervous System.DEMENTIA IN ICD-10In ICD-10, the dementias are embedded in the section on organicand symptomatic mental disorders (codes F00–F09), whichcontains the following major rubrics:. Dementia in Alzheimer’s disease.. Vascular dementia.. Dementia in diseases classified elsewhere.. Unspecified dementia.. Organic amnesic syndrome, other than induced by alcohol anddrugs.. Delirium, other than induced by alcohol and drugs.. Other mental disorders due to brain damage and dysfunctionand to physical disease.. Personality and behavioural disorders due to brain disease,damage and dysfunction. Unspecified organic or symptomatic mental disorder.In contrast to ICD-9, the distinction between psychotic andnon-psychotic illnesses is of no taxonomic consequence in ICD-10, where disorders of different psychopathological expression aregrouped together on the basis of established or presumed commonaetiology. In the particular instance of section F0, in which thedementing disorders are included, the underlying classificatorycharacteristic of ‘‘organic’’ is defined in the sense that ‘‘thesyndrome so classified can be attributed to an independentlydiagnosable cerebral or systemic disease or disorder’’. Thesubsidiary term ‘‘symptomatic’’ is not used in the titles ofindividual disorders but it is included in the overall title of theblock F00–F09. This is because it is widely used in many countriesto indicate those organic mental disorders in which cerebralinvolvement is secondary to a systemic extra-cerebral disease ordisorder. In other words, ‘‘symptomatic’’ in this context is asubdivision of the wider term ‘‘organic’’.Another feature of ICD-10, as compared to earlier classifications,is the omission of any reference to age as a defining criterionof the disorders accompanied by a cognitive deficit. The terms‘‘senile’’ and ‘‘presenile’’ are practically absent in the classification,and there is no provision for identifying any mental disorderas necessarily a result of ageing. The classification does, however,Principles and Practice of Geriatric Psychiatry, 2nd edn. Edited by J. R. M. Copeland, M. T. Abou-Saleh and D. G. Blazer&2002 John Wiley & Sons, Ltd