Psychiatric Diagnosis and Classification - part 2 docx

ratings. Moreover, a series of such changesÐfrom DSM-III to DSM-III-R to DSM-IV to DSM-V, for exampleÐrisks discrediting the whole process of psychiatric classification. Many difficult decisions about the balance of advantage and disadvantage will therefore be required. Because the dis- advantages of minor changes will generally be as substantial as those of major changes, there ought, in our view, to be a prejudice against minor changes, even if this results among other things in perpetuating irritating differences between the ICD and DSM definitions of some individual dis- orders [48]. Perhaps the greatest weakness of DSM-IV and ICD-10 is their classifica- tion of personality disorders. Both provide a heterogeneous set of categories of disorder and in both cases individual patients commonly meet the criteria for two or three of these categories simultaneously. As there is much evi- dence that human personality is continuously variable, and all contempor- ary classifications of the variation in normal personality are dimensional, there is a strong case for a dimensional classification of personality dis- orders and it is possible that this will be provided by DSM-V. Evolution of Concepts and the Language of Psychiatry It is important to maintain awareness of the fact that most of psychiatry's disease concepts are merely working hypotheses and their diagnostic cri- teria are provisional. The present evolutionary classification in biology would never have been developed if the concept of species had been defined in rigid operational terms, with strict inclusion and exclusion cri- teria. The same may be true of complex psychobiological entities like psy- chiatric disorders. Perhaps both extremesÐa totally unstructured approach to diagnosis and a rigid operationalizationÐshould be avoided. Defining a middle range of operational specificity, which would be optimal for stimu- lating critical thinking in clinical research, but also rigorous enough to enable comparisons between the results of different studies in different countries, is probably a better solution. Impact of Neuroscience and Genetic Research on Psychiatric Classification It has been suggested that clinical neuroscience will eventually replace psychopathology in the diagnosis of mental disorders, and that phenom- enological study of the subjective experience of people with psychiatric illnesses will lose its importance. Such a transformation of clinical psy- chiatry would replicate developments in other medical disciplines where CRITERIA FOR ASSESSING A CLASSIFICATION IN PSYCHIATRY 21 molecular, imaging and computational tools have largely replaced trad- itional clinical skills in making a diagnosis. In time, such developments might result in a completely redesigned classification of mental disorders, based on genetic aetiology [49]. The categories of such a classification and their hierarchical ordering may disaggregate and recombine our present clinical categories in quite unexpected ways, and eventually approximate to a ``natural'' classification of psychiatric disorders. This, indeed, is already happening in general medicine where molecular biology and genetics are transforming medical classifications. New organiz- ing principles are producing new classes of disorders, and major chapters of neurology are being rewritten to reflect novel taxonomic groupings such as diseases due to nucleotide triplet repeat expansion or mitochondrial diseases [50]. The potential of molecular genetic diagnosis in various medical dis- orders is increasing steadily and is unlikely to bypass psychiatric disorders. Although the majority of psychiatric disorders appear to be far more com- plex from a genetic point of view than was assumed until recently, molecular genetics and neuroscience will play an increasing role in the understanding of their aetiology and pathogenesis. However, the extent of their impact on the diagnostic process and the classification of psychiatric disorders is diffi- cult to predict. The eventual outcome is less likely to depend on the know- ledge base of psychiatry per se, than on the social, cultural and economic forces that shape the public perception of mental illness and determine the clinical practice of psychiatry. A possible but unlikely scenario is the advent of an eliminativist ``mindless'' psychiatry which will be driven by biological models and jettison psychopathology. It is much more likely in our view that clinical psychiatry will retain psychopathology (i.e. the systematic analysis and description of subjective experience and behavior) at its core. It is also likely that classification will evolve towards a system with at least two major axes: one aetiological, using neurobiological and genetic organizing con- cepts, and another syndromal or behavioral±dimensional. The mapping of two such axes onto one another would provide a stimulating research agenda for psychiatry for the foreseeable future. REFERENCES 1. American Psychiatric Association (1980) Diagnostic and Statistical Manual of Men- tal Disorders, 3rd edn (DSM-III). American Psychiatric Association, Washington. 2. American Psychiatric Association (1987) Diagnostic and Statistical Manual of Mental Disorders, 3rd edn, revised (DSM-IIIR). American Psychiatric Association, Washington. 3. World Health Organization (1992) The ICD-10 Classification of Mental and Behav- ioural Disorders. Clinical Descriptions and Diagnostic Guidelines. World Health Organization, Geneva. 22 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION 4. American Psychiatric Association (1994) Diagnostic and Statistical Manual of Mental Disorders, 4th edn (DSM-IV). American Psychiatric Association, Wash- ington. 5. World Bank (1993) World Development Report 1993: Investing in Health. Oxford University Press, New York. 6. Sokal R.R. (1974) Classification: purposes, principles, progress, prospects. Sci- ence, 185: 115±123. 7. Kant I. (1970) The Essential Kant (Ed. A. Zweig). Mentor Books, New York. 8. Nelson K. (1973) Some evidence for the cognitive primacy of categorization and its functional basis. Merril-Palmer Quarterly of Behavior and Development, 19: 21±39. 9. Rosch G., Mervis C.B., Gray W., Johnson D., Boyes-Braem P. (1976) Basic objects in natural categories. Cogn. Psychol., 8: 382±439. 10. Millon T. (1991) Classification in psychopathology: rationale, alternatives, and standards. J. Abnorm. Psychol., 100: 245±261. 11. Scadding G. (1993) Nosology, taxonomy and the classification conundrum of the functional psychoses. Br. J. Psychiatry, 162: 237±238. 12. Horowitz L.M., Post D.L., French R. de S., Wallis K.D., Siegelman E.Y. (1981) The prototype as a construct in abnormal psychology: 2. Clarifying disagree- ment in psychiatric judgments. J. Abnorm. Psychol., 90: 575±585. 13. Cantor N., Smith E.E., French R., Mezzich J. (1980) Psychiatric diagnosis as prototype categorization. J. Abnorm. Psychol., 89: 181±193. 14. Feinstein A.R. (1972) Clinical biostatistics. XIII: On homogeneity, taxonomy and nosography. Clin. Pharmacol. Ther., 13: 114±129. 15. Shepherd M., Brooke E.M., Cooper J.E., Lin T.Y. (1968) An experimental approach to psychiatric diagnosis. Acta Psychiatr. Scand. Suppl. 201. 16. Rosch E. (1975) Cognitive reference points. Cogn. Psychol., 7: 532±547. 17. Sullivan P.F., Kendler K.S. (1998) Typology of common psychiatric syndromes. Br. J. Psychiatry, 173: 312±319. 18. Bonhoeffer K. (1909) Zur Frage der exogenen Psychosen. Zentralblatt fu È r Ner- venheilkunde, 32: 499±505. 19. Essen-Mo È ller E. (1961) On the classification of mental disorders. Acta Psychiatr. Scand., 37: 119±126. 20. Robins E., Guze S.B. (1970) Establishment of diagnostic validity in psychiatric illness: its application to schizophrenia. Am. J. Psychiatry, 126: 983±987. 21. Kendler K.S. (1980) The nosologic validity of paranoia (simple delusional dis- order). A review. Arch. Gen. Psychiatry, 37: 699±706. 22. Andreasen N.C. (1995) The validation of psychiatric diagnosis: new models and approaches. Am. J. Psychiatry, 152: 161±162. 23. Sneath P.H.A. (1975) A vector model of disease for teaching and diagnosis. Med. Hypotheses, 1: 12±22. 24. Crow T.J., DeLisi L.E. (1998) The chromosome workshops at the 5th Inter- national Congress of Psychiatric GeneticsÐthe weight of the evidence from genome scans. Psychiatr. Genet., 8: 59±61. 25. Kendler K.S. (1996) Major depression and generalised anxiety disorder: same genes, (partly) different environmentsÐrevisited. Br. J. Psychiatry, 168 (Suppl. 30): 68±75. 26. Brown G.W., Harris T.O., Eales M.J. (1996) Social factors and comorbidity of depressive and anxiety disorders. Br. J. Psychiatry, 168 (Suppl. 30): 50±57. 27. Widiger T.A., Clark L.A. (2000) Toward DSM-V and the classification of psy- chopathology. Psychol. Bull., 126: 946±963. CRITERIA FOR ASSESSING A CLASSIFICATION IN PSYCHIATRY 23 28. Cloninger C.R. (1999) A new conceptual paradigm from genetics and psycho- biology for the science of mental health. Aust. N. Zeal. J. Psychiatry, 33: 174±186. 29. Cloninger C.R., Martin R.L., Guze S.B., Clayton P.J. (1985) Diagnosis and prog- nosis in schizophrenia. Arch. Gen. Psychiatry, 42: 15±25. 30. Sigvardsson S., Bohman M., von Knorring A.L., Cloninger C.R. (1986) Symptom patterns and causes of somatization in men: I. Differentiation of two discrete disorders. Genet. Epidemiol., 3: 153±169. 31. Woodbury M.A., Clive J., Garson A. (1978) Mathematical typology: a grade of membership technique for obtaining disease definition. Computers and Biomed- ical Research, 11: 277±298. 32. Manton K.G., Korten A., Woodbury M.A., Anker M., Jablensky A. (1994) Symp- tom profiles of psychiatric disorders based on graded disease classes: an illus- tration using data from the WHO International Pilot Study of Schizophrenia. Psychol. Med., 24: 133±144. 33. Faraone S.V., Tsuang M.T. (1994) Measuring diagnostic accuracy in the absence of a ``gold standard''. Am. J. Psychiatry, 151: 650±657. 34. Kendell R.E. (1989) Clinical validity. Psychol. Med., 19: 45±55. 35. Stengel E. (1959) Classification of mental disorders. WHO Bull., 21: 601±663. 36. Bridgman P.W. (1927) The Logic of Modern Physics. Macmillan, New York. 37. Bleuler E. (1950) Dementia Praecox, or the Group of Schizophrenias. International Universities Press, New York. 38. Schneider K. (1959) Clinical Psychopathology. Grune & Stratton, New York. 39. Rice J.P., Rochberg N., Endicott J., Lavori P.W., Miller C. (1992) Stability of psychiatric diagnoses: an application to the affective disorders. Arch. Gen. Psychiatry 49: 824±830. 40. Hempel C.G. (1961) Introduction to problems of taxonomy. In Field Studies in the Mental Disorders (Ed. J. Zubin), pp. 3±22. Grune & Stratton, New York. 41. Grayson D.A. (1987) Can categorical and dimensional views of psychiatric illness be distinguished? Br. J. Psychiatry, 26: 57±63. 42. Skinner H.A. (1986) Construct validation approach to psychiatric classification. In Contemporary Directions in Psychopathology (Eds T. Millon, G.L. Klerman), pp. 307±330. Guilford Press, New York. 43. Fabrega H. (1992) Diagnosis interminable: toward a culturally sensitive DSM- IV. J. Nerv. Ment. Dis., 180: 5±7. 44. Hyman S.E. (1999) Introduction to the complex genetics of mental disorders. Biol. Psychiatry, 45: 518±521. 45. Ginsburg B.E., Werick T.M., Escobar J.I., Kugelmass S., Treanor J.J., Wendtland L. (1996) Molecular genetics of psychopathologies: a search for simple answers to complex problems. Behav. Genet., 26: 325±333. 46. Eisenberg L. (2000) Is psychiatry more mindful or brainier than it was a decade ago? Br. J. Psychiatry, 176: 1±5. 47. Jablensky A. (1999) The nature of psychiatric classification: issues beyond ICD- 10 and DSM-IV. Aust. N. Zeal. J. Psychiatry, 33: 137±144. 48. Andrews G., Slade T., Peters L. (1999) Classification in psychiatry: ICD-10 versus DSM-IV. Br. J. Psychiatry, 174: 3±5. 49. Kendell R.E. (2000) The next 25 years. Br. J. Psychiatry, 176: 6±9. 50. Grodin M.A., Laurie G.T. (2000) Susceptibility genes and neurological dis- orders. Arch. Neurol., 57: 1569±1574. 24 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION CHAPTER 2 International Classifications and the Diagnosis of Mental Disorders: Strengths, Limitations and Future Perspectives T. Bedirhan U È stu È n 1 , Somnath Chatterji 1 and Gavin Andrews 2 1 Department of Evidence for Health Policy, World Health Organization, Geneva, Switzerland 2 School of Psychiatry, University of New South Wales at St. Vincent's Hospital, Darlinghurst, Australia INTRODUCTION The classification of mental disorders improved greatly in the last decade of the twentieth century and now provides a reliable and operational tool. A common way of defining, describing, identifying, naming, and classify- ing mental disorders was made possible by the International Classification of Diseases (ICD), Mental Disorders chapter [1, 2] and the Diagnostic and Statistical Manual of Mental Disorders (DSM) [3]. General acceptance of the ICD and DSM rests on the merits of their descriptive and ``operational'' approach towards diagnosis [4]. These classifications have greatly facili- tated practice, teaching and research by providing better delineation of the syndromes. The absence of aetiological information linked to brain phy- siology, however, has limited understanding of mental illness and has been a stumbling block to the development of better classifications. This chapter reviews the strengths and limitations of the ICD system as a common classification for different cultures and explores the issues around future revisions given the expectations of scientific advances in the fields of genet- ics, neurobiology, and cultural studies. Psychiatric Diagnosis and Classification. Edited by Mario Maj, Wolfgang Gaebel, Juan Jose  Lo  pez-Ibor and Norman Sartorius. # 2002 John Wiley & Sons, Ltd. Psychiatric Diagnosis and Classification. Edited by Mario Maj, Wolfgang Gaebel, Juan Jose  Lo  pez-Ibor and Norman Sartorius Copyright # 2002, John Wiley & Sons, Ltd. ISBNs: 0±471±49681±2 (Hardback); 0±470±84647±X (Electronic) Limits of Our Knowledge about Mental Disorders Classification of mental disorders creates great interest because it offers a synthesis of our current knowledge of those disorders. A classification reflects both the nature of mental disorders (i.e. ontology) and our approach to know them (i.e. epistemology). Like the periodic table of elements which displays properties of atoms in meaningful categories, the classification of mental disorders may yield some knowledge about the ``essence'' of under- lying mechanisms of mental disorders. At the same time, organization of the classification may reflect the conceptual path of how we know and group various mental disorders. Having all this knowledge organized in a classifi- cation presents a challenge for consistency and coherence. It also helps us to identify shortcomings of our knowledge and leads to further research on unresolved issues. Classification of mental disorders has traditionally started from a prac- tical effort to collect statistical information and make comparisons among patient groups. Today its greatest use is for administrative and reimburse- ment purposes. However, it has also gained importance as a ``guide'' in teaching and clinical practice, because of its special nature of bringing mental disorders into mainstream medicine. Since earlier practice of psych- iatry and behavioral medicine was mainly based on clinical judgement and speculative theories about aetiology, the introduction of operational diagnostics allowed for demystification of non-scientific aspects of various practices. Current classification systems mainly remain ``descriptive''. They aim to define the pathology in terms of clinical signs or symptoms and formulate them as operational diagnostic criteria. These criteria are a logically coher- ent set of quantifiable descriptors that aim to identify the presence of a psychopathology. Our knowledge today, with a few exceptions, does not allow us to elucidate the underlying mechanism as to what actually consti- tutes the disorder or produces the symptom. The path from appearances to essence depends on the progress of scientific knowledge. As scientific knowledge advances, we become aware that the current ``descriptive'' system of classifications, however, does not fully map on the neurobiology in terms of its pathophysiological groupings. For example, obsessive-compulsive disorder, which has been shown to have a totally different neural circuit, has been grouped together with anxiety disorders [5±7]. Similarly, despite the hair-splitting categorizations of anxiety and depressive disorders with complex exclusion rules, clinical and epidemi- ological studies indicate high rates of comorbidity and similar psychophar- macological agents prove efficacious in their treatment [8±11]. Despite the belief of distinct genetic mechanisms between schizophrenia and bipolar disorders, family studies have shown the concurrent heritability [12]. Such 26 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION examples will inevitably accumulate to identify paradoxes between the appearance and the essence (i.e. the underlying mechanisms). The classification of mental disorders is built on observation of patho- logical human behaviors. It identifies patterns of signs or symptoms that are stable over time and across different cultural settings, and can be informed by new knowledge of the way the mind and brain work. Such a classifica- tion is a reflection of (a) natural observable ``phenomena'', (b) cultural ways of understanding these, and (c) the social context in which these experiences occur. Since one of the major purposes of a diagnostic classification is to help clinicians communicate with each other by identifying patterns linked to disability, interventions and outcomes, these classifications have often evolved based on the ``sorting techniques'' that clinicians use. All psychi- atric classifications are therefore human tools intended for use within a social system. Therefore, in thinking about the classification of mental dis- orders, multiple factors need to be taken into account, simply because our understanding of genetics, physiology, individual development, behavioral patterns, interpersonal relations, family structures, social changes, and cul- tural factors all affect how we think about a classification. The twentieth century has been marked by several distinct phases in the way mental phenomena and disorders have been understood. The determinism of psy- choanalysis and early behaviorism has been superseded by the logical empiricism of biological psychiatry that is searching for the underpinnings of human behavior in the brain in particular, and in human biology in general. Our current knowledge of mental disorders remains limited be- cause of the lack of disease-specific markers, and is largely based on obser- vation of concurrent behavioral and psychological phenomena, on response to pharmacological and other treatments and on some data on familial aggregation of these elements. The task of creating an international classifi- cation of mental disorders is, therefore, a very challenging multiprofessional and multicultural one that seeks to integrate a variety of findings within a unifying conceptual framework. STRENGTHS OF ICD-10: A RELIABLE INTERNATIONAL OPERATIONAL SYSTEM The ICD is the result of an effort to create a universal diagnostic system that began at an international statistical congress in 1891 with an agreement to prepare a list of the causes of death for common international use. Subse- quently, periodic revisions took place and in 1948, when the World Health Organization was formed, the sixth revision of the ICD was produced. Member states since then have decided to use the ICD in their national health statistics. The sixth revision of the ICD for the first time contained a INTERNATIONAL CLASSIFICATIONS 27 separate section on mental disorders. Since then extensive efforts have been undertaken to better define the mental disorders. There has been a syn- chrony between ICD-6 and DSM-I, ICD-8 and DSM-II, ICD-9 and DSM-III and ICD-10 and DSM-IV with increasing harmony and consistency thanks to the international collaboration. In the most recent tenth revision of the ICD (ICD-10), the mental disorders chapter has been considerably expanded and several different descriptions are available for the diagnostic categories: the ``clinical description and diagnostic guidelines'' (CDDG) [1], a set of ``diagnostic criteria for research'' (DCR) [2], ``diagnostic and management guidelines for mental disorders in primary care'' (PC) [13], ``a pocket guide'' [14], a multiaxial version [15] and a lexicon [16]. These interrelated components all share a common founda- tion of ICD grouping and definitions, yet differentiate to serve the needs of different users. In the ICD-10, explicit diagnostic criteria and rule-based classification have replaced the art of diagnosis with a reliable and replicable system that has considerable predictive validity in terms of effective interventions. Its devel- opment has relied on international consultation and has been linked to the development of assessment instruments. The mental disorders chapter of the ICD-10 has undergone extensive testing in two phases to evaluate the CDDG as well as the DCR. The field trials of the CDDG [17] were carried out in 35 countries where joint assessments were made of 2460 different patients. For each patient, clinicians who were familiarized with the CDDG were asked to record one main diagnosis and up to two subsidiary diagnoses. Inter-rater agreements, as measured by the kappa statistic, for most categories in the ``two-character groups'' (e.g. F2, schizophrenic disorders) were over 0.74, indicating excellent agreement. It was lowest at 0.51 for the F6 category, which includes personality disorders, disorders of sexual preference, dis- orders of gender identity and habit and impulse disorders. At a more detailed level of diagnosis, agreement on individual personality disorders (except dyssocial personality disorder), mixed anxiety and depression states, somatization disorder and organic depressive disorder were below accept- able limits. As a result, the descriptions for these categories were improved and clarified. Some categories were omitted altogether from the ICD-10 due to poor reliability (e.g. the category of hazardous use of alcohol). Based on the experience gathered from the field trials of the CDDG, the ICD-10 DCR were developed with the assistance of experts from across the world. Operational criteria with inclusion and exclusion rules were specified for each diagnostic category. For the DCR field trials [18], 3493 patients were assessed in a clinical interview by two or more clinicians across 32 countries. Once again, for the F6 category the kappa value of 0.65 (though improved from the CDDG field trials) was lower than for the other 9 two character categories, which all had kappas over 0.75. For the more detailed diagnoses, 28 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION poor kappa values of <0.4 were obtained mainly for those categories that were either polymorphic syndromes (e.g. acute psychotic disorders) or were at the milder end of the spectrum (e.g. hypomania, mild depressive episode). LIMITATIONS OF CLASSIFICATION OF MENTAL DISORDERS IN THE ICD The new classification systems have generally greatly facilitated teaching, clinical practice, scientific research, and communication. What then are the problems? Classification by Syndromal Similarity The ICD categories are grouped by their syndromal similarity, i.e. the common clustering of a set of symptoms and signs in clinical practice with no other organizing principle deemed to be necessary. This approach may, however, not always be valid, since a higher order rule may override apparent similarities or differences. For example, given external character- istics, one may intuitively classify sharks and dolphins as fish, based on the similarities in appearance and the nature of the habitat. Yet, this would obviously be false as a higher order rule dictates that dolphins are mammals and sharks are not. Categories in the ICD (and DSM) having passed the test of expert consensus (and therefore providing the face validity that they are indeed commonly identifiable patterns in clinical patients) do not always make scientific sense and may have created boundaries where none exists. For example, it appears arbitrary (and therefore unacceptable) to classify the severe end of the psychosis spectrum as a ``disorder'' while classifying the milder version within the personality disorder group. In fact the current criteria for schizophrenia in both DSM and ICD have been viewed as having serious limitations as they rely heavily on psychotic symptoms that may be the final common pathway for a variety of disorders. Features occurring before the advent of psychosis that are clinical, biological, and/or neuro- psychological in nature may provide more information about the genetic, pathophysiological, and developmental origins of schizophrenia [19]. The separation of the diagnostic criteria from aetiological theories was an explicit approach undertaken to avoid being speculative, since these theor- ies about causation had not been empirically tested. However, this ``atheore- tical'' approach has also been severely criticized because, if one takes a totally atheoretical and solely operational approach, it may be possible to classify normal but statistically uncommon phenomena as psychiatric dis- orders [20]. Diagnostic categories have been proposed and accepted merely INTERNATIONAL CLASSIFICATIONS 29 because of recognizable patterns of co-occurring symptoms rather than be- cause of a true understanding of their distinctive nature that would make them discrete categories within a classification. What Defines a Mental Disorder? While ICD is a classification of diseases (or ``disorders'' in the context of mental illness), there is no explicit agreement on the definition of a mental disorder. Despite the call for a definition [21], no agreement has been forthcoming and this ambiguity creates a fuzzy boundary between disorder and wellness. At the lowest level, a mental disorder is an identifiable and distinct set of signs and symptoms that commonly produce disability, and that the healers in the society claim to be able to ameliorate through various interventions. While practical, such a definition can lead to error, e.g. homo- sexuality was once defined as a disorder. The answer to the question ``What is a disorder?'' needs to be evaluated against rigorous scientific standards rather than just from societal or per- sonal points of view. A disorder may be defined by a set of general prin- ciples that characterize a specific entity, such as common aetiology, signs and symptoms, course, prognosis and outcome. It may then have other correlates, such as familial aggregation (due to genetic or contextual factors), a pattern of distress or disability, and a predictable range of outcomes following a variety of specific interventions. Robins and Guze [22], in their classic paper, proposed five phases for establishing the validity of psychi- atric diagnosis: clinical description, laboratory studies, delimitation from other disorders, follow-up study to show diagnostic homogeneity over time, and family study to demonstrate the familial aggregation of the syndrome. Experience gathered since then shows that some of these criteria lead to contradictory conclusions. For example, if one wants to define schizophre- nia by its diagnostic stability over time, the best approach is to define the illness at the very outset by a duration criterion of six months of continuous illness, which tends to select for subjects with a poor outcome. In contrast, the familial aggregation of schizophrenia is best demonstrated when the notion of the disorder is broadened to include the notion of ``schizotaxia''Ð a broad spectrum notion that views the predisposition to schizophrenia to be characterized by negative symptoms, neuropsychological impairment and neurobiological abnormalities and schizophrenia to be a psychotic neurotoxic end-point in the process. The latter approach suggests that narrowing the definition of schizophrenia using the former strategy may in fact hinder progress in identifying the genetic causes of the disorder [19]. The lack of a definition of what is a disorder also creates an ambiguity about so-called ``sub-threshold'' disorders. Many have shown the presence 30 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION [...]... other national classifications, particularly DSM In the evolution of DSM and ICD, since the sixth version of ICD 40 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION and first version of DSM, there has been a constant effort to get closer ICD-8 and DSM-II, ICD-9 and DSM-III and ICD-10 and DSM-IV have displayed greater similarity and consistency thanks to the international collaboration The ICD and DSM in their... Stone W.S., Faraone S.V (20 00) Toward reformulating the diagnosis of schizophrenia Am J Psychiatry, 157: 1041±1050 INTERNATIONAL CLASSIFICATIONS 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 45 Bentall R.P (19 92) A proposal to classify happiness as a psychiatric disorder J Med Ethics, 18: 94±98 Kendler K.S., Neale M.C., Kessler R.C., Heath A.C., Eaves L.J (19 92) A population based study... ongoing coordination of   Psychiatric Diagnosis and Classification Edited by Mario Maj, Wolfgang Gaebel, Juan Jose Lopez-Ibor and Norman Sartorius # 20 02 John Wiley & Sons, Ltd 48 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION efforts to develop classification systems by both the APA and the international scientific community After a review of the strengths and limitations of the DSM-IV, the chapter concludes... reliability and 46 41 42 43 44 45 46 47 48 49 50 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION validity of the alcohol and drug use disorder instruments: overview of methods and results Drug Alcohol Depend., 47: 161±169 Henderson A.S., Blackwood D.H (1999) Molecular genetics in psychiatric epidemiology: the promise and challenge Psychol Med., 29 : 126 5± 127 1 Baron M (20 01) Genetics of schizophrenia and the new... for psychoses I Situation of the problem and methodology Encephale, 10: 119± 123 Andrews G., Slade T., Peters L (1999) Classification in psychiatry: ICD-10 versus DSM-IV Br J Psychiatry, 174: 3±5 First M.B., Pincus H.A (1999) Classification in psychiatry: ICD-10 v DSM-IV A response Br J Psychiatry, 175: 20 5 20 9 Farmer A., McGuffin A (1999) Comparing ICD-10 and DSM-IV Br J Psychiatry, 175: 587±588 È È Ustun... 851±864  Âpez-Ibor and Norman Sartorius Psychiatric Diagnosis and Classification Edited by Mario Maj, Wolfgang Gaebel, Juan Jose Lo Copyright # 20 02, John Wiley & Sons, Ltd ISBNs: 0±471±49681 2 (Hardback); 0±470±84647±X (Electronic) CHAPTER 3 The American Psychiatric Association (APA) Classification of Mental Disorders: Strengths, Limitations and Future Perspectives Darrel A Regier1 ,2, Michael First3,... sites, particularly chromosomes 1q, 4q, 5p, 5q, 6p, 6q, 8p, 9q, 10p, 13q, 15q, 22 q, and Xp [ 42] Similarly, for bipolar disorders, several genetic loci on chromosomes 4p, 12q, 13q, 18, 21 q, 22 q and Xq have been reported [43] The chromosomal regions implicated are large However, the use of data sets that have detailed phenotypic information, of marker-intensive genome-wide searches for linkage and association,... multicultural and multidisciplinary approach to a series of focused field trials In organizing, conducting and funding such a collaborative, goal-directed effort, the WHO should and could play a seminal role With international research we could build better classifications that can lead to better understanding of mental disorders 44 PSYCHIATRIC DIAGNOSIS AND CLASSIFICATION REFERENCES 1 2 3 4 5 6 7 8 9 10 11 12. .. 49: 25 7 26 5 Robins E., Guze S.B (1970) Establishment of diagnostic validity in psychiatric illness: its application to schizophrenia Am J Psychiatry, 126 : 983±987 Hasin D., Paykin A (1999) Dependence symptoms but no diagnosis: diagnostic ``orphans'' in a 19 92 national sample Drug Alcohol Depend., 53: 21 5 22 2 Pincus H.A., Davis W.W., McQueen L.E (1999) ``Subthreshold'' mental disorders A review and. .. Health Organization (19 92) The ICD-10 Classification of Mental and Behavioural Disorders: Clinical Descriptions and Diagnostic Guidelines World Health Organization, Geneva World Health Organization (1993) The ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research World Health Organization, Geneva American Psychiatric Association (1994) Diagnostic and Statistical Manual . studies. Psychiatric Diagnosis and Classification. Edited by Mario Maj, Wolfgang Gaebel, Juan Jose  Lo  pez-Ibor and Norman Sartorius. # 20 02 John Wiley & Sons, Ltd. Psychiatric Diagnosis and Classification. . disorders. There has been a syn- chrony between ICD-6 and DSM-I, ICD-8 and DSM-II, ICD-9 and DSM-III and ICD-10 and DSM-IV with increasing harmony and consistency thanks to the international collaboration. In. to get closer. ICD-8 and DSM-II, ICD-9 and DSM-III and ICD-10 and DSM-IV have displayed greater similarity and consistency thanks to the international collaboration. The ICD and DSM in their current