SPECIAL ARTICLE

Issues in the Oassification of Child and Adolescent Psychopathology

DENNIS P. CANTWELL, M.D., AND LORIAN BAKER, PH.D.

Abstract. This paper discusses classification of child and adolescent psychopathology and, in particular, theDSM-III-R psychiatric classification system. The significance ofcertain conceptual features of the DSM-Ill system(such as the categorical approach to classification, the multiaxial framework, and the descriptive atheoretical viewofdisorders) is discussed. The DSM system is evaluated in terms ofits reliability, validity, coverage, and feasibilityfor clinical use. Some of the specific changes made between DSM-III and DSM-III-R are considered. Finally, thefuture of classification of child and adolescent psychopathology is considered. J. Am. Acad. Child Adolesc.Psychiatry, 1988, 27, 5:521-533. Key Words: Classification system, DSM-III, DSM-III-R, reliability, validity,feasibility.

The publication of DSM-lII in 1980 was a landmark inpsychiatric nosology. It was the culmination of an interest inclassification of psychiatric disorders that had been growingfor some 20 to 25 years. The publication ofDSM-IIl has hada major impact not only on clinical practice but also onteaching, research, and the development ofpsychiatric assess­ment instruments. A complete discussion of all these issues isbeyond the scope of this article but can be found in Skodoland Spitzer (1987).

DSM-IIl differs in many ways from its two predecessors,DSM-l and DSM-II. One of the most significant differencesis the much more extensive coverage given to the classificationof childhood disorders. Both DSM-l and DSM-II includedvery few disorders with onsets in infancy, childhood, or ado­lescence; however, DSM-lII has more than quadrupled thenumber ofsuch diagnostic categories (Bemporad and Schwab,1986).

DSM-lII-R follows the conceptual framework ofDSM-lII,and, consequently, retains many of its innovations andstrengths. Unfortunately, DSM-IIl-R also perpetuates manyof the difficulties and weaknesses inherent in DSM-III. Inaddition, DSM-lll-R has strengths and weaknesses that reflectits own specific and unique characteristics. As a result, thepublication ofDSM-IIl-R has generated both renewed interestand renewed controversy in the classification of psychiatricdisorders of infancy, childhood, and adolescence.

Thus, this seems an apt time to review pertinent issues inthe nosology of psychiatric disorders. In this article, bothgeneral issues about classification ofpsychiatric disorders andspecific issues relating to the classification of child and ado­lescent psychopathology are addressed. The strengths andweaknesses of the DSM-IIl-R classification system, including

Accepted May 16, 1988.Dr. Cantwell is Joseph Campbell ProfessorofChild Psychiatry and

Director of Residency Training in Child Psychiatry. Dr. Baker isResearch Psychollnguist: Both are with the University of Californiaat Los Angeles, Neuropsychiatric Institute, 760 Westwood Plaza, LosAngeles, CA 90024.

Reprint requests to Dr. Cantwell.0890-8567/88/2705-O521$02.00/0© 1988 by the American Acad­

emy of Child and Adolescent Psychiatry.

those that are inherent in DSM-IIl framework and those thatare specific to DSM-IIl-R, are discussed. Finally, classifica­tions for the future (including DSM-lVand lCD-lO) areconsidered.

Space precludes a complete discussion ofall pertinent issuesin the classification of child and adolescent psychopathology.The interested reader is referred to Cantwell (1985; 1987a andb) and Rutter et al. (1988).

Purpose of Classification and History

Classification is a process of imposing order on complexdata by grouping the data into categories based on sharedcharacteristics. In child psychiatry, as in other psychiatricfields, a classification system facilitates communication bypermitting the use ofdiagnostic labels in place ofa full listingof all the features of a patient's disorder. In addition, theexistence of a classification system permits more rapid re­trieval of information and generation and verification ofhypotheses and concepts.

Historically, there have been some objections to psychiatricclassification. Szasz (1961; 1978) has described such an ap­proach as "justifactory rhetoric," lacking any substantivemeaning and producing harmful effects that include socialstigma and social deprivation. Huschka (1941) complainedthat classification may obscure individual differences andprevent detailed understanding ofdisorders. As. Weiner (1982)observed, however, most of the so-called harmful effects ofpsychiatric classification result from misapplication or abuseof the system and not from the classification system per se. Itis now generally acknowledged that the disadvantages ofclassification are greatly outweighed by the numerous advan­tages of having such a system (Kendall, 1975; Weiner, 1982).

The history ofchild psychiatry has been rich with a numberof systems for classifying disorders (Menninger et al., 1963).Among the more highly developed of these systems are theDevelopmental Profile (A. Freud, 1965); the GAP Report(Group for the Advancement of Psychiatry, 1966, 1974); theInternational Classification of Diseases, Ninth Edition (lCD­9) (World Health Organization [WHO] 1978), the DSM-II,DSM-lII, and DSM-lII-R systems (American Psychiatric As-

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522 CANTWELL AND BAKER

sociation [APA] 1968, 1980, 1987, respectively), and theMultivariate Factorial approach (as exemplified by the ChildBehavior Profile of Achenbach and Edelbrock [1983]).

Currently, there is no single classification system recognizedas being the "natural" or "right" system. There are certainobjective criteria, however, by which the effectiveness ofparticular classification systems have traditionally beenjudged (Cantwell, 1987a,b; Cantwell, 1988; Quay, 1986; Rut­ter, 1965; Rutter et al., 1975; Spitzer and Williams, 1980).These criteria include reliability, validity, coverage, and fea­sibility. Each of these criteria are discussed further below withregard to the DSM-II/-R classification system.

Conceptual Features of DSM-III-R

As stated above, DSM-I/I-R retains the conceptual frame­work ofDSM-II/. Thus, many of the innovative strengths ofDSM-II/ as well as many of its weaknesses remain in DSM­II/-R. Below, the value of three of the key features of theDSM-I/I classification system-the descriptive atheoreticalview, the categorical approach to classification, and the mul­tiaxial framework-is discussed.

Descriptive(Atheoretical) Approach

In a desire to be acceptable to a wide range of professionals,the DSM-II/ system has taken an atheoretical approach tothe definition and classification of mental disorders. Thus,the disorders listed in DSM-I/I-R are described for the mostpart in terms of observable clinical features. This use of apurely descriptive framework is a departure from previousclassification systems for childhood psychiatric disorders, in­cluding the GAP system and Anna Freud's system.

The lack of an underlying theoretical framework for theDSM-I/I system has been both denied and deplored. Denialof the atheoretical framework is exemplified in the writingsof Salzinger (1986), who states that there are "hidden theoret­ical underpinnings of the medical model." Conversely,Eysenck (1986, p, 91) criticizes the DSM-I/I classification forhaving disorders "generally incapable of being absorbed intoany kind of theoretical or causal system." Nonetheless , it isgenerally recognized that there is a lack of attention to possiblecausal criteria (be they psychodynamic, social, or organic) inthe DSM system, and this lack of attention is a practicalapproach to "the reality that most ofthe disorders we currentlyencounter have no established etiologic or even patho­physiologic basis" (Klerman, 1986).

The classification categories of DSM-II/-R are defined withspecificdiagnostic criteria consisting of identifiable behavioralsigns or symptoms. The categories, which require a minimalamount of inference on the part of the observer, are muchmore explicit than the definitions of any previous psychiatricclassification system. In the DSM-II/ system, both essentialand associated features are described for each disorder, andcriteria are given for exclusion from the various categories.

The specific diagnostic criteria in DSM-II/ have tradition­ally been called "operational diagnostic criteria ." Althoughthe criteria are specific (in the sense that they specify theessential features of disorders), they are not operational (inthe sense that they do not specify the operation that musttake place for the diagnosis to be made).

Proponents of the dimensional (multivariate) approach toclassification of psychiatric disorders consider the absence ofoperational criteria to be among the major failings of theDSM systems. Under the dimensional system (described inmore detail below), definitions of disorders are tied to specificscores on specific assessment instruments. Nonetheless, theDSM framework itself does not necessarilyprecludethe estab­lishment of operational criteria for its specific diagnoses. Forexample, DSM-II/-R now requires that standardized testscores be used to establish such diagnoses as developmentalarithmetic disorder, developmental reading disorder, devel­opmental expressive language disorder, and mental retarda­tion. Because of the lack of the standardized tests that spanthe entire age range of children and adolescents, however,particular tests are not yet specified for these DSM-I/I-Rdiagnoses.

Another criticism of the specific diagnostic criteria ap­proach of DSM-I/I has been made by Rutter and Shaffer(1980). They observed that for many of the childhood psy­chiatric disorders there are inadequate data available to estab­lish specificdiagnostic criteria. These authors complained thatthe DSM precise diagnostic criteria failed to reflect this igno­rance and inaccurately suggested firm knowledge. Similarly,Millon (1983, 1986) criticized the DSM categories as beinginsufficiently explicit, excessively concrete, and insufficientlycomprehensive. Katschnig and Simhandl (1986, p. 220) fur­ther warned that the explicit criteria DSM-III might be "dan­gerous" insofar as "even clinically inexperienced personsmight be tempted to classify patients along such diagnosticcriteria."

CategoricalApproach

As with most classification systems for childhood psychi­atric disorders, the DSM system consists of categories thatwere derived from initial clinical impressions. Another ap­proach to the classification ofchildren's psychiatric disorders,generally known as the dimensional method, begins withmathematical and statistical procedures to measure the tend­ency of specific items of behavior to occur together. Oncethese "dimensions ofbehavior" are identified (for example byfactor analysis), individuals or patients can be classified intomutually exclusive groups (e.g., using cluster analysis). Theuse of mathematical procedures eliminates unreliability of aninterobserver type that can occur when two clinicians com­bine the same data differently. Different results however, canbe obtained in dimensional classifications, depending uponthe mathematical criteria selected. For example, some tech­niques will allow the investigator to say how similar patientsmust be in order to be grouped together. Other techniquesrequire that the investigator begin by specifying the numberof categories to be used. Some techniques allow for unclassi­fied patients, whereas others do not. Studies of adult patientshave shown that, depend ing on the methods of analysis used,the same patients can be classified in different groupings(Pfohl and Andreasen, 1978).

Achenbach (1982; Achenbach and Edelbrock, 1978, 1981)is a leading proponent of the dimensional (multivariate statis­tical) approach. He reports that, in general, the syndromesthat are evolved from dimensional (multivariate) studies can

CHILD AND ADOLESCENT PSYCHOPATHOLOGY 523

be divided into broadbandand narrow band syndromes. Thebroad band syndromes can be likened to DSM-lII generalcategories (e.g., anxiety disorders), whereas the narrow bandsyndromes can be likened to the more specific diagnosticcategoriesof DSM-lII (e.g.,separation anxiety disorder). Ach­enbach has made detailed comparisons of DSM-IIl categori­cal syndromes and his empirically defined narrow band syn­dromes and has found that (1) there were DSM-lII disordersthat did not appear to have empirical counterparts; (2) therewere empirically derived syndromes that did not appear tohave categorical counterparts; and (3) there were a consider­able number of syndromes that occurred in both the multi­variate studies and in the categorical system.

Thus, there is empirical support for only some of the DSMcategories. Proponents of the dimensional approach to cate­gorization consider a major argument for their system to bethe fact that all its classifications are empirically derived.Thus, because of its empirical foundation, the dimensionalapproach produces groupings that are more reliable, morehomogeneous, and more closelytied to their assessment tools.Also, because the classification is based on numerical scoresobtained on specific assessment tools, a patient's responses totreatment can be more easily determined under the dimen­sional system. In addition, the dimensional approach providesmaximal coverage, because arbitrary cut-off scores are estab­lished in order to categorize all individuals. However, therequirement that each individual be categorized into one andonly one class presents problems when patients have morethan one psychiatric illness. Such patients are more naturallyhandled by the categorical system, under which it is simple tospecify membership in more than one class.

Another problem with the dimensional approach is that,although factor analysis and principle component analysisproduce statistically meaningful correlates between items, thestatistically significant dimension of behavior created may notbe clinically or theoretically meaningful. For example, Edel­brock and Achenbach (1980) illustrated how cluster analysiscan create homogeneous groupings even when applied torandom data. Another difficulty with the dimensional ap­proach is that its categories, being based on mathematicalscores, require cumbersome definitions. Not being tied toclinical intuition, the dimensional categoriesare more difficultto remember and are less likely to facilitate professionalcommunication.

Robins (1976) compared the likely long-term utility of thecategorical and dimensional approaches and concluded thatthe categorical approach is potentially more clinically useful.He cautioned, however, that greater attention to empiricaldata is needed within the categorical system. For example,the accuracy of the methods of obtaining information mustbe monitored; more information must be obtained about thevarious psychiatric disorders; the normal and abnormal rangesfor psychiatric disorders must be established from data; andfinally, diagnostic criteria must be revised when indicated bydata.

Along the lines of these suggestions, Pfohl and Andreasen(1978) have written an interesting paper illustrating howmultivariate techniques can be used in combination with amore clinically based approach to establish a classification

system. They outline four steps in the establishment of acategorical classification system: (1) the selection of patientsand variables to be studied; (2) the division of these patientsinto groups; (3) the development of diagnostic criteria (fromthe essential features of the groups that were created in step2); and (4) the evaluation of the diagnostic system (in termsof reliability and validity). Pfohl and Adreasen point out thateach of the steps can be accomplished by combining clinicaljudgment with particular statistical methods. They conclude,as did Robins, that clinical judgment will continue to playamajor and indispensable role in the creation of diagnosticsystems.

Multiaxial Format

A third key feature of the DSM-lII system is its multiaxialformat, in which classificationsare based on severaldomains.Specifically, DSM-lII-R uses five axes: I. psychiatric clinicalsyndromes and conditions for evaluation and/or treatment;II. developmental and personality disorders; III. relevant phys­ical conditions; IV. psychosocial stressors; and V. overallfunctioning. The use of a multiaxial format represents a majorshift away from previous psychiatric classifications(includingthe leD system, the GAP system, and DSM-l and -II).

The multiaxial approach is based on recognition that clin­ical diagnosis involves different elements that do not neces­sarilyconstitute alternatives to each other (Rutter and Shaffer,1980). The advantages of the multiaxial system of classifica­tion include (1) more thorough knowledge of the patient'scondition (Mezzich, 1980); (2) greater interdisciplinary value(Cantwell and Baker, in press); and (3) less likelihood thatcertain diagnoses will be omitted or forgotten (Rutter et al.,1975).

In general, the DSM-lII system's use of a multiaxial formathas been considered to be one of its major conceptualstrengths (Achenbach, 1980;Cantwell, 1985; Klerman, 1986;Rutter and Shaffer, 1980). In addition, several field studieshave shown the clinical value of the multiaxial system. Spitzerand Forman (1979) found that clinicians judged the multiax­ial format to be a useful addition to traditional diagnosticevaluation, and Russell et al. (1979) found that the use of themultiaxial system led to greater reliability and to more com­plete diagnosing of complex clinical cases.

There have, however, been some criticisms associated withthe DSM's multiaxial format. These have centered aroundthe choice of specific axes, the ways in which certain of theaxes are coded, and issues of the quasi-independence of theaxes(Mezzich, 1980).Criticisms ofthe so-called"psychosocialaxes" (Axis IV and Axis V) of DSM-lII have resulted incertain revisions found in DSM-IIl-R. These are discussedfurther below.

Another axis that has received criticism is Axis II. Inparticular, nonpsychiatrists have attacked the inclusion, inAxis II, of the specificdevelopmental disorders. There is somefeelingthat the developmental speech/language disorders andthe specific learning disorders are not an appropriate part ofa psychiatric diagnosis, and therefore do not belong in DSM­III. Garmezy (1977/78) exemplifies this view, labeling theDSM-IIl an "overreaching effort ... to bring under the psy-

524 CANTWELL AND BAKER

chiatrist's wing deficits and disabilities that are not mentaldisorders. "

The inclusion of the specific developmental disorders onAxis II is an important and valuable aspect of the DSMsystem for several reasons. First, both language and learningdisorders are frequently associated with impaired social skills,peer relationships and self-esteem (Baker and Cantwell, inpress). Thus, these Axis II disorders may constitute reason forpsychiatric intervention, even when there is no Axis I disorderpresent.

Second, (Axis I) clinical psychiatric disorders are commonlyassociated with Axis II specific developmental disorders. Arecent study of preschool-age children referred for psychiatricevaluation revealed that even in such a young age group, 59%had an Axis II diagnosis (Kashani et al., 1986). Among olderchildren, it has been well documented that the Axis I diagnosesof attention-deficit hyperactivity disorder and conduct disor­der are very likely to co-occur with learning disorders (Keogh ,1971; Rutter et al., 1975). The coding of these disorders onAxis II highlights the need for a multidisciplinary approachto both initial diagnosis and ultimate treatment. Appropriatepsychiatric treatment of children with concurrent Axis I andII diagnoses must consider the possible interaction effects ofthe developmental disorder.

Third, developmental language disorders share presentingfeatures with various psychiatric syndromes, including autisticdisorder, elective mutism, pervasive developmental disorder,and schizophrenia (Cantwell and Baker, 1987). The inclusionof the developmental language disorders on their own axismakes them less likely to be forgotten for differential diag­nosis.

Evaluation of the DSM-lII-R Oassification System

The following section of this article evaluates the impact ofthe DSM system in terms of its overall reliability, validity,coverage, and feasibility for clinical use.

Reliability

The reliability of a classification system refers to the degreeto which all clinicians using the system would arrive at thesame diagnosis for a given patient. The reliability of a classi­fication system may be affected by a number of differentfactors: ( I) the information provided ("information vari­ance"); (2) the interpretation ofthe information ("observationand interpretation variance"); and (3) the criteria for sum­marizing data into diagnoses ("criterion variance") (Spitzerand Williams, 1980).

The basic procedure for testing the reliability of a classifi­cation system involves either one clinician diagnosing thesame patients more than once or several clinicians diagnosingthe same patients at the same time. Various statistical proce­dures (such as percent agreement, specific agreement, oragreement corrected for chance) are then used to computethe agreement between the various diagnoses (Bartko andCarpenter, 1976).

The authors are not aware of any publications dealing withthe reliability of DSM-Ill-R. There are, however, a numberof publications that have examined the reliability of DSM-IIIin both epidemiological and clinical samples of children andadolescents (APA, 1980; Canino et al., 1987; Cantwell et al.,

1979; Earls, 1982; Fernando et al., 1986; Hyler et aI., 1982;Mattison et al., 1979; Mezzich et al., 1985; Rey et aI., 1987;Russell et aI., 1979; Strober et aI., 1981; Werry et al., 1983).

Although the figures obtained have differed in the variousreliability studies, the general finding across studies is that theDSM-III system is at least as reliable if not more so than theDSM-II system (Cantwell et al., 1979, 1980; Mezzich et aI.,1985). The reliability of diagnoses made using a dimensionalclassification system is generally higher because the onlysource for disagreement is in the selection of the variousalgorithms to be used. Once these are selected, the reliabilityis 100%.

The overall reliability of the DSM-III Axis I diagnoses hasranged across studies from a low of 0.37 in a study of childand adolescent patients (Mezzich et aI., 1985) to a high of0.70 in a study of hospitalized adolescent patients (Strober etal., 1981). The reliabilities of diagnoses on Axes II to V appearto be somewhat higher than the reliability of diagnoses onAxis I (Cantwell et al., 1979; Mezzich et al., 1985; Plapp etal., 1987; Russell et aI., 1979). This is not an unexpectedfinding because diagnoses on these other axes generally pro­vide a smaller range of choices.

Certain of the DSM-III Axis I specific diagnoses showedconsistently higher reliabilities, and certain of the Axis Ispecific diagnoses showed lower reliabilities. Among the morereliable of the DSM-III Axis I childhood diagnostic categorieswere attention deficit disorder, conduct disorder, separationanxiety disorder, and psychosis. Because the diagnostic crite­ria for these disorders have been changed in DSM-III-R, it isnot certain whether these categories would still have higherreliability.

Validity

Validity refers to the extent to which a procedure measureswhat it purports to measure. Spitzer and Williams (1980)enumerated four types of validity that are relevant to theeffectiveness of a psychiatric diagnostic classification's cate­gories: (1) face validity (correspondence with clinicians' intu­itions); (2) descriptive validity (uniqueness of each category);(3) predictive validity (ability to predict outcome); and (4)construct validity (relationship to theories). From the clinicalstandpoint, predictive validity is probably the most importantof these. A clinician needs to know that a particular diagnosiswill predict something (such as untreated natural history ,likely response to different intervention, or family pattern ofpsychiatric illness).

Several specific models have been devised for testing thevalidity of diagnostic classification systems. One such model ,developed at the Washington University Department of Psy­chiatry by Robins and Guze and their colleagues (Feighner etaI., 1972; Robins and Guze, 1970), comprises five stages: (1)clinical description, (2) delimitations from other disorders, (3)laboratory studies, (4) family studies, and (5) follow-up stud­ies. This model was subsequently expanded into a six-stagemodel designed specifically for the validation of childhoodpsychiatric disorders (Cantwell , 1975): (1) essential and ass0­

ciated features of the disorder, and the exclusionary criteria;(2) physical and neurological studies; (3) laboratory studies;(4) family psychopathology studies and family interactionstudies; (5) follow-up studies; and (6) treatment studies.

CHILD AND ADOLESCENT PSYCHOPATHOLOGY 525

Klerman (1983) suggested a somewhat different and ex­panded model for validating psychiatric syndromes, bothinternally and externally. Internal consistency would be de­termined by correlational statistical methods. External criteriawould include biological laboratory correlates, family aggre­gation and family interaction studies, follow-up studies, treat­ment studies, psychosocial factors (such as life stressors andlife events, early developmental experiences in childhood, andparticular personality patterns), and lastly, epidemiologicaldata (e.g., prevalence rates, morbidity risk, and lifetime ex­pectancy).

No large-scale validity studies of DSM-III-R have beendone. In fact, because many of the childhood diagnosticcategories were described for the first time in DSM-III, theylack long-term natural history and treatment data. Nonethe­less, as mentioned above, dimensional studies of childhoodpsychopathology have provided empirical validation for someof the DSM-III-R diagnostic categories: attention deficit­hyperactivity disorder, conduct disorder, overanxious disor­der, schizoid disorder, elective mutism, and gender identitydisorder (Achenbach, 1980). These and many of the otherDSM-III-R Axis I diagnostic categories have face validity inthe opinions of many clinicians. However, certain of theDSM-III-R diagnoses (e.g., avoidant disorder and opposi­tional disorder) have been criticized as particularly lackingvalidity (Achenbach, 1980; Garmezy, 1977/78; Quay, 1983;Rutter and Shaffer, 1980; Tanguay, 1984). Validity problemswith several of the specific revisions in DSM-III-R are dis­cussed below.

Feasibility

Feasibility refers to the extent to which a classificationsystem can be successfully used by the professionals for whomit is designed (in this case, for clinicians in practice). Rutterand Gould (1985) list a number of requirements for a classi­fication system to be feasible: it must use only routinelyavailable information; have clear, simple, and unambiguousinstructions for use; and be in a form convenient for statisticalhandling. Jablensky (1986) cites certain other features of aclassification system that are appropriate: the system should"satisfy the cognitive needs of users by being in accordancewith their 'world maps,' avoiding jargon, being easy to learnand 'internalize,' and by generally being 'user-friendly,' ...[and] be fitted with a key for the translation of past classifi­catory systems or other current classifications" (p. 564).

To some degree, the widespread, albeit not entirely uncrit­ical, acceptance of DSM-III is sufficient testament to itsfeasibility. As Spitzer et al. (1983) have documented, thesystem has been used throughout Europe, Japan, Australia,New Zealand, and various Third World countries. Specifi­cally, in the United States and Canada, the willingness ofinsurance companies and institutions to adopt the DSM-III­R diagnostic categories attests to its convenience for statisticalhandling. Similarly, there is little question that the diagnosticcriteria of DSM-III-R requires only routinely available infor­mation. This will be increasingly true as more and morepsychiatric assessment instruments (e.g., interviews and ques­tionnaires) are updated to be compatible with DSM-III-Rdiagnoses.

Several features have been incorporated in DSM-III-R to

decrease any ambiguity in its instructions. These include thelisting of explicit diagnostic criteria for each of the disorders,the systematic organizational formats by which each disorderis described, revised decision trees for differential diagnosis, aglossary of technical terms, and comparative listings withDSM-III and ICD diagnoses. These devices aim to provideclarifications of the diagnoses as well as classification princi­ples to aid the clinician. Their success, however, is open toquestion.Forexample,~illon(1983,p.809)validlycriticized

the diagnostic decision trees as being an "unnecessary en­cumbrance" imposing "a procedural complexity on an oth­erwise facile and expedient process." This issue aside, theestablishment of diagnostic decision trees may be prematureat the present time. As Costello (1982) has demonstrated,little is known about how clinicians integrate data to arrive ata specific diagnosis.

Two studies have examined the feasibility of the DSM-IIIchildhood classification system in comparison to the DSM-IIsystem (Mezzich and Mezzich, 1985; Russell et al., 1983).Russell et al. (1983) surveyed child psychiatry fellows andfaculty in a clinical setting who were using DSM-III for thefirst time. They found that, despite unfamiliarity with thesystem, most of these clinicians perceived it to be a useful andpractical system. Subsequently, Mezzich and Mezzich (1985)compared DSM-II and DSM-III for feasibility in large ran­dom samples of clinical child psychologists and child psychi­atrists. They found that the conceptual appropriateness, defi­nitional clarity, and usefulness of categories were all consid­ered by both the psychologists and the psychiatrists as to bebetter in DSM-III than in DSM-II. In addition, the feasibilityofthe diagnostic criteria for certain of the DSM-III-R child­hood diagnoses was examined in field tests of some 550children across the United States.

Coverage

Coverage describes the degree to which a classificationsystem provides for the classification of all patients. Withregard to psychiatric classification, coverage is measuredagainst the proportion of patients with "undiagnosed mentaldisorder." Goodwin and Guze's research (1979) found that,for adults, categorical psychiatric diagnosis using strict diag­nostic criteria generally results in at least 25% of the psy­chiatrically ill receiving a diagnosis of "undiagnosed mentaldisorder." (Of course, such a situation would not occur undera dimensional classification system where all individualswould be forced into some category.

The coverage provided by DSM-III-R is among the mostcomprehensive ofany (categorical) psychiatric system. DSM­III-R specifies 36 diagnoses that are "first evident in infancy,childhood and adolescence," in addition to a number of othercategories also applicable to children. This large number ofdiagnostic categories is a result of the DSMs decision to takea splitter (as opposed to a lumper) approach. Thus, finesubdivisions of disorders are specified whenever face validitycan be established. This increased coverage, however, hasresulted in a number of subcategories with lower reliabilityand external validity. The value of the splitter approach isdiscussed further below with specific examples of some of thechanges in DSM-Ill-R. Obviously, it would be easier at somefuture time to collapse subcategories than to subdivide existingcategories.

526 CANTWELL AND BAKER

Issues in the Revision of DSM-III

As we have seen above, many of the controversial issuesconcerning DSM-III-R are issues inherent in the selection ofa particular type of classification system. This includes theselection of a categorical or dimensional system, the choiceof a uniaxial or multiaxial system, and the underlying theo­retical approach to be taken. A particular classification systemmay be evaluated by objective criteria such as reliability,validity, feasibility, and coverage. However, as there is fre­quently a trade-offbetween these criteria, it is open to contro­versy as to which of these criteria are most critical.

Another aspect of DSM-III-R is the specific revisions thatwere made from the earlier DSM-III edition. As these revi­sions do not represent changes in the type of classificationsystem itself, they are somewhat easier to evaluate. Below,several ofthese revisions are discussed, including the additionof some disorders, the moving of some diagnoses from Axis Iand Axis II, changes in the diagnostic criteria for some of thedisorders, and additions and deletions of certain diagnoses.Before this, however, some discussion of the historical back­ground to DSM-III-R is necessary.

HISTORICAL PERSPECTIVES AND PROCESSES

OF DSM-III-R

It has been argued that the revision of DSM-III was pre­mature. Recall that DSM-III was published in 1980 and manyofits disorders had only face validity at that time. The splitterapproach was taken in DSM-III so that these disorders couldbe investigated for reliability and validity. When the work onDSM-III-R began, however, few of these disorders had beenadequately investigated (Cantwell, 1987b). Furthermore, di­agnoses such as infantile autism had been incorporated intoeducational and legal decisions. Changes in such categories,then, should have been initiated only in the presence of asignificant amount of scientific evidence supporting the newcriteria.

The rationale for the revision of DSM-III was that sincethe basic elements of the draft of DSM-III were completed in1978, a revision published some 8 or 9 years later couldprovide a timely refinement of its criteria. This rationale,however, supports only "minor tinkering" with the basicDSM-III document. In fact, the authors believe that at thetime of the revision, wholesale changes in DSM-III wereunjustified because ofthe lack ofavailable scientific evidence.

In fact (as examples below will show) many of the changesin DSM-III-R were not merely "minor tinkering" but ratherwere significant changes in the classification criteria that werebased only on limited data. As Werry (1988) points out, thishas resulted in a two-fold loss. First, considerable amounts ofreliability and validity data that had been collected for theDSM-III syndromes are now irrelevant in the face of thenewly defined syndromes. And second, the various psychiatricassessment instruments that were keyed to the DSM-III cri­teria (for example, the DISC and K-SADS) require revision.

Another historical problem is the process by which DSM­III was revised. DSM-III itself has been criticized as being"the outcome of large-scale committee work, designed not somuch to ascertain facts and to arrive at the truth, but rather

to reconcile different power groups" (Eysenck, 1986, p. 74).In fact, DSM-III was drafted by committees that were madeup of groups of experts in various fields. These drafts, how­ever, were subsequently circulated to other professionals, and,in addition, considerable field testing was done before thefinal publication.

With DSM-III-R, however, the criticism is more valid:fewer people were involved in construction of its first draft,and its field testing was quite limited. Furthermore, the dead­lines for publication precluded serious debate by a larger groupofchild psychiatrists. Thus, as Werry (1988) complains, DSM­III-R was finalized even in the areas of childhood psycho­pathology, by the APA committee "in which child psychia­trists were a tiny minority."

SPECIFIC CHANGES IN DSM-III-R

In one of the first commentaries on DSM-III-R to reachpublication, Dumont (1987, p. 11) wrote: "Most of thechanges are of this variety: 'attention deficit disorder withhyperactivity' becomes 'attention-deficit hyperactivity disor­der.' 'Stereotyped movement disorders' becomes 'tic disor­ders.' And, dramatically, 'tobacco withdrawal' is now 'nic­otine withdrawal."

These comments suggest that the modifications betweenDSM-III and DSM-III-R are rather trivial or whimsical,consisting of nothing more than new nomenclature for oldsyndromes. This is hardly the case, however. Examination ofsome of the changes from DSM-III to DSM-III-R revealsdifferent scopes to several ofthe multiaxial domains; differentcoding procedures for several axes; new categories of disor­ders; and deletions of other disorders. Even within "generallysimilar" categories of disorders, the revisions have includedmarked differences in conceptualization, subcategorizations,and diagnostic criteria. Rather than being trivial or noncon­sequential, many of these changes will have considerableeffects on the reliability, validity, and feasibility of the newDSM-III-R system.

Space here precludes a detailed analysis ofall ofthe specificchanges seen in DSM-III-R, but several of the changes thatare particularly relevant to the classification of childhoodpsychopathology are illustrated and critiqued. These includechanges in the conceptualization and specific diagnostic cri­teria for the disruptive behavior disorders (attention deficitdisorder, conduct disorder, and oppositional disorder) andthe developmental disorders (pervasive developmental disor­ders and specific developmental disorders) and the modifica­tion of the "psychosocial axes" (Axis IV and Axis V). Puig­Antich (1987) has commented on the changes in mood dis­orders as they apply to children and adolescents. The presentauthors agree with his views and will not comment further onmood disorders.

AttentionDeficitDisorder Syndrome

The disruptive behavior disorders are common diagnosesin child and adolescent psychiatry. The most prevalent ofthese disruptive behavior disorders, the attention deficit dis­order syndrome, has been modified considerably betweenDSM-III and DSM-III-R. In DSM-III, the general category

CHILD AND ADOLESCENT PSYCHOPATHOLOGY 527

of attention deficit disorder had three subtypes: attentiondeficit disorder with hyperactivity (ADDH); attention deficitdisorder without hyperactivity (ADDW); and attention deficitdisorder, residual type (ADDR).

The criteria for ADDH required three symptoms of inat­tention, three symptoms of impulsivity, and two symptomsofhyperactivity, plus age of onset and duration requirements.The diagnostic criteria for ADDW included the symptoms ofinattention and impulsivity but no symptoms of hyperactiv­ity. The diagnosis of ADDR was made for patients who hadformerly met the criteria for ADDH, had no current signs ofhyperactivity, but had other persistent symptoms resulting inimpairment in social and occupational function. Thus, inDSM-III, the category of attention deficit disorder was aclinical diagnosis requiring symptoms in various domains ofbehavior.

In DSM-III-R, these syndromes are represented by a cate­gory named attention deficit-hyperactivity disorder (ADHD)that is somewhat similar in form to Wender's (1971) conceptof "minimal brain dysfunction." The category is polythetic(i.e., no specific single symptom or set of symptoms is neces­sary or sufficient criteria for the diagnosis). Thus, rather thanthe DSM-III clinical diagnosis with a conceptualization ofdifficulties in various specific behavioral domains, DSM-III­R lists 14 possible symptoms of which any eight must bepresent. DSM-III-R also has onset and duration criteria andspecifies three possible levels of severity.

The ADDW and ADDR subcategories seen in DSM-III areeliminated from DSM-III-R. DSM-III-R, however, has ageneral convention for specifying residual state forms of dis­orders. This means that the basic difference with regard toADDR is a change in the specific diagnostic criteria, namely,that in DSM-III-R it is no longer required that there be signsof hyperactivity.

Conversely, with regard to ADDW, there is no directlycomparable category in DSM-Ill-R. Instead, DSM-III-R hasa category called undifferentiated attention-deficit disorder(UADD) meant to capture "disorders involving attentionaldifficulties that are not symptoms of another disorder." Inthis disorder, there are no signs ofimpulsivity or hyperactivity.

The rationale given for deleting the ADDW category wastwofold. First, that "the diagnosis is hardly ever made" and,second, that "it is unlikely that the DSM-III categories ofattention deficit disorder with and without hyperactivity aresubtypes ofa single disorder" (APA, 1987, p. 411).

The authors believe that the dropping of the ADDW sub­type is a mistake. Although there is little question that thesyndrome is most commonly manifested by signs of motorhyperactivity, the authors disagree that ADDW is a diagnosisthat is "rarely made." In their epidemiological study of 600children presenting to a large community speech and hearingclinic, this diagnosis was made in a total of nine cases(Cantwell and Baker, 1985). Considering that the ADDWdiagnostic category was first formalized with the publicationof DSM-III in 1980, the research literature has providedevidence of a surprising number of cases (Berry et al., 1985;Carlson, 1986; Carlson et al., in press; Edelbrock et al., 1984;King and Young, 1982; Lahey et al., 1985; Maurer andStewart, 1980; Pelham et al., 1981; Sergeant and Scholten,1985).

The research literature comparing ADDH and ADDW isinconclusive. Barkley (1981) wrote that the literature providedno evidence that the ADDH/ADDW distinction resulted inany greater diagnostic homogeneity or improved prognosticinformation. Carlson's (1986) literature review, however, con­cluded that the behavior patterns displayed by the attentiondeficit disorder groups were so dissimilar that it seemed"unlikely that they should be considered ... a single disorder."The differences between ADDW and ADDH children thathave been reported in the literature include both behavioraldifferences (in the areas ofaggression/conduct, social relation­ships, affective symptomatology, impulsivity) (Berry et al.,1985; Edelbrock et al., 1984; King and Young, 1982; Laheyet al., 1985) and cognitive/learning differences (Carlson et al.,in press; Maurer and Stewart, 1980; Sergeant and Scholten,1985).

The ADDW children from the authors' speech clinic sample(unpublished data) resembled the ADDH children in manybehavioral and cognitive variables . Nonetheless, it was theauthors' clinical impression that these children represented "adifferent type of ADD," a clinical impression that was cap­tured by the DSM-III ADDW category. Under DSM-III-Rcriteria, these children met the criteria for ADHD but did notmeet the criteria for UADD because they had symptoms ofimpulsivity. Thus, the authors' impression of clinical distinct­ness could be captured in DSM-III-R. Whether this impres­sion is valid can be determined only with additional data. Forexample, it is possible that the authors' follow-up research(now in data analysis) may reveal differential outcomes forthe ADDW children as compared to the ADDH children. Atany rate, the authors feel that the literature does suggest thatthe ADDW category may be valid and that, at the very least,the ADDW category should have been retained for furtherstudy.

The authors also feel that the diagnostic criteria for ADHDare poorly selected. As stated above, the ADHD diagnosis isa polythetic category that does not require any particularsymptoms and instead lists 14 symptoms, any eight of whichmay be present. The symptoms are listed "in descending orderof discriminating power" based on data from a national fieldtrial for the DSM-III-R.

This attempt has been evaluated by Rutter (1988, p, 456),who considers it "certainly . . . good that research findingswere employed so directly in formulating diagnostic criteria,but . . . most unfortunate that DSM-III-R gives no details ofeither the strategy or results of the field trials so that readerscan make their own judgements about the validity of thedecisions taken." The judgment of the present authors, basedon some familiarity with these field trials, is that they do notmeet the standards ofa solid scientific study. In this particularinstance, the symptomatology derived from these field trialscorresponds with neither the authors' own clinical impressionsnor the symptom data (unpublished) that they have collectedon a large number of children with this syndrome. In short,the description is not, in the words of Jablensky (1986) "inaccordance with ... [our] 'world maps.''' At any rate, theauthors agree with Werry's (1988, p. 139) comment that thenew ADDH criteria "jettison the data of 17 years for thou­sands ofcases ... in favor ofa hastily-derived largely untestedJohnny-corne-lately set of criteria."

528 CANTWELL AND BAKER

OtherDisruptive Behavior Disorders

The two other categories of disruptive behavior disorders,conduct disorder and oppositional defiant disorder, have bothbeen revised in DSM-lII-R. Examples of symptomatologyhave been expanded in both categories to clarify the distinctivefeatures of the disorders.

Under DSM-IIl, oppositional disorder required only twoof the following five symptoms: violations of minor rules,temper tantrums, argumentativeness, provocative behavior,and stubbornness. Oppositional defiant disorder (as the syn­drome is renamed in DSM-IIl-R) requires that five of ninesymptoms be present: often losing temper, often arguing withadults, often actively defying adult requests; often deliberatelyannoying people; often blaming others; often being touchy,often being angry and resentful; often being spiteful or vin­dictive; and often swearing or using obscene language. Thus,the revision highlights defiance as a key aspect of the disorderand decreases the likelihood that the diagnosis could be usedwith essentially normal children. Another advantage of therevision is that the overlap with and evolution into conductdisorder is made more explicit. As Rutter (1988, p, 456)observes, this "may not be sufficient to satisfy ... [everyone],but clearly the changes are in the right direction."

The revisions of conduct disorder were somewhat moreradical. In DSM-IIl, there were four subtypes of conductdisorder: (1) undersocialized aggressive, (2) undersocializednonaggressive, (3) socialized aggressive, and (4) socializednonaggressive. The differential diagnosis depended on a pat­tern of aggressive behavior that either was or was not associ­ated with a failure to establish a normal degree of affection,empathy, or bonding with others. In DSM-IIl-R there hasbeen a major change in the subtyping. Instead of the foursubtypes based on the presence or absence of aggressive be­havior and on the presence or absence of significant peerrelationships, DSM-lII-R lists three subtypes: group type,isolated aggressive type, and undifferentiated type. In addi­tion, the descriptive criteria for conduct disorder in DSM-IIl­R are improved, being both more comprehensive and moredevelopmental in nature than the symptom pattern providedin DSM-III.

The authors feel that the expanded descriptive criteria forconduct disorder provided in DSM-lII-R are a definite im­provement over the DSM-lII version. The DSM-IIrs exam­ples of aggression were too closely tied to legal definitions ofdelinquency. These symptoms (such as rape, mugging, androbbery), in fact, are rarely seen in most conduct disorderedchildren, particularly younger ones.

The DSM-IIl-R's changes in subgrouping are more prob­lematic. The rationale for the change was "to reflect a majordistinction seen in the research literature: aggressiveantisocialbehavior that is not conducted in a group setting . " andantisocial behavior that is conducted in a group setting .. ."(APA, p. 411).

In the authors' interpretation, the research literature doesnot clearly support such a drastic change from the foursubtypes in DSM-lII to the three subtypes in DSM-IIl-R. Infact, the subtyping ofconduct disorder is a controversial area,with the literature providing evidence of the validity ofseveraldifferent approaches to the subtyping of conduct disorder.

For example, Quay's (1964) analysis of the behaviors of maledelinquents found four distinct factors: socialized, unsocial­ized/psychopathic [=aggressive], overinhibited, and inade­quate/immature. Wolff's later (1971) cluster analysis of pri­mary-school-aged clinic patients found two separate groups:aggressive/overactive and antisocial. Achenbach 's (1978,1985; Achenbach and Edelbrock, 1981; Achenbach et al.,1987) factor analysis research has suggested two separatefactors of conduct disorder: aggressive versus nonaggressiveantisocial . Somewhat similarly, Loeber and Schmaling (1985)found that conduct disorders generally, but with some over­lap, tend to fall into "overt" and "covert" subtypes. Patterson(1982) found two subtypes of conduct disordered children(aggressors and stealers) that differed not only in primarysymptomatology but also in family structure variables. Theearlier work of Moore and colleagues (Moore et al., 1979)also found stealing to be a key discriminator: children withthis symptom had significantly worse prognoses 2 to 9 yearslater. Rutter and Giller's (1984) review of the literature ondelinquent children concluded that the socialized/underso­cialized dichotomy is the most valid method of subgrouping.They found that the socialized subtype had better long-termprognoses and that the two subtypes were additionally vali­dated by different family backgrounds. Finally, recent epide­miological studies in new Zealand (Anderson et al., 1987) didnot find evidence for any subgroups of conduct disorder otherthan aggressivesocialized.

The present authors do not feel that these contradictoryresearch findings justify the major change in DSM-lII-R.Certainly, additional study is needed in this area, but itappears that the socialized/unsocialized and aggressive/un­aggressive subtypes may all have some predictive validity,particularly when age and sex differences are considered (Em­pey, 1982; Jenkins, 1979; Robins, 1966; Wolff, 1985). Anadditional problem with the DSM-IIl-R subgroups concernsits ultimate compatibility with the leD classification system.This is discussed in more detail below.

Axis II Disorders

Several of the specific changes for DSM-lII-R involve theAxis ITdevelopmental disorders. In DSM-IIl-R, mental retar­dation, the specific developmental disorders, and the perva­sive developmental disorders are all coded on Axis II. Therationale for this was that these disorders "share all the featuresofgenerally having an onset in childhood or adolescence andusually persisting in a stable form without periods ofremissionor exacerbation into adult life." (APA, 1987, p, 410).

The authors support the change ofpervasive developmentaldisorder and mental retardation from an Axis I category inDSM-lII to an Axis II category in DSM-IIl-R. They alsosupport the refinement of certain Axis II diagnoses: e.g., thesplitting of developmental language disorder into two separatecategories (developmental expressive language disorder anddevelopmental receptive language disorder). Under DSM-IIl,these classifications were viewed as mutually exclusive; theclinician was forced to choose between a predominantly ex­pressive disorder and a predominantly receptive disorder.Under DSM-lII-R, the clinician can now code the co-occur­rence of the two disorders or the occurrence of a singledisorder. Furthermore, when the types of language disorders

CHILD AND ADOLESCENT PSYCHOPATHOLOGY 529

are present, the clinician can now identify different levels ofseverity that may be present for each.

This particular change exemplifies the DSM splitter ap­proach. There is currently little consensus among speech/language pathologists regarding the subclassificationsof typesof developmental language disorders (Cantwell and Baker,1987). To date, three studies using empirical methods tosubclassifysamples of children with developmental languagedisorder have been published (Aram and Nation, 1975; Rapinand Allen, 1983;Wilson and Risucci, 1986).A vastly differentmodel as theoretical basis for classification has been used foreach (Aram and Nation's model was psycholinguistic; Rapinand Allen's model was a combined processing and psycho­linguistic model; and Wilson and Risucci's model was aneuropsychological-processingmodel). In each of the studies,however, three broad categories of disorders have appeared:an expressive subtype, a receptive subtype, and a mixedexpressive-receptive subtype. The revised classification inDSM-III-R is now able to capture these three categories in away that DSM-III could not.

Another Axis II change involves the categories of infantileautism and pervasive developmental disorder. In DSM-IIIthere was an overall category of pervasive developmentaldisorder with three subtypes: infantile autism, childhood onsetpervasive developmental disorder, and (a residual category)atypical pervasive developmental disorder. In DSM-III-R, thepervasive developmental disorder category has only two sub­types: autistic disorder and the residual category now calledpervasive developmental disorder not otherwise specified.

The diagnostic criteria for autistic disorder in DSM-III-Rare considerably changed from those of infantile autism inDSM-III. There is expanded focus on speech and language inthe diagnostic criteria, which the present authors feel may beuseful for differential diagnoses. The category has been un­necessarily broadened, however, so that many children witha variety of disorders other than classical "Kanner Autism"will now be given a diagnosis of infantile autism. Because ofthe wide range of functioning permitted under the new diag­nostic criteria, virtually all autistic-like children fall into thesingle diagnostic category of PDD. Thus, severely retardedautistic children fall into the same categoryas high functioningchildren with atypical personality development.

The research in the field of autism is currently movingtoward delineating subtypes of autistic-like syndromes (Cohenet al., 1986; Levine and Demb, 1987; Noll and Benedict,1981; Shapiro et al., 1987). For example, Cohen et al. (1986)propose a continuum of categories that include "AutisticPDD" (for low functioning autistics), "Kanner's autism," and"Multiplex developmental disorder" for children who wouldfall into the "atypical" category under DSM-III. One prom­ising recent study (Siegel et al., 1986)has found not only thatsubgroups produced by multidimensional classification pro­cedures correspond to some of these clinically derivedsubgroups but that these subgroups can be validated to someextent by perinatal and developmental markers. Thus, thereis now increasingjustification for splitting the autism categoryinto more clearly defined subgroups rather than lumping thecategory into an overly broad category.

A final change in Axis II of DSM-III-R that the authorswould like to mention is the addition of a new diagnostic

category, developmental expressivewriting disorder. This is alearning disorder manifested by difficultiesin written language(including spelling, punctuation, syntax, grammar, and/orsentence formation). Although it has long been recognizedthat such difficulties may occur independent of difficulties inoral reading (Myklebust, 1965), little is known about thedisorder in terms of the epidemiology, course, or etiology.Clinicians and educators, however, have ample documenta­tion of the frequency with which written language problemsare seen (Wiig and Semel, 1976). Although this syndromelacks validity other than face validity, now that It has beenformalized, it is hoped that validity studies will commence.

AXES IV AND V

The final specificmodification in DSM-III-R discussedhereinvolves certain changes in the psychosocial axes (Axes IVand V). After the publication of DSM-III, these axes were thesubject of considerable criticism. It was noted that, in com­parison to the other axes of DSM-III, these were relativelycrude (Roth, 1983), poorly systematized (Kendall, 1983), notparticularly useful in clinical practice (Montero et al., 1986)and, in fact, frequently ignored by clinicians (Mezzich et al.,1982). Reliability studies indicated problems with these axes(Fernando et al., 1986; Rey et al., 1987). Consequently, it isnot surprising that they have been revised.

The revision of Axis IV, the psychosocial stressor axis,centered around the coding of the stressors. Under DSM-III,the clinician was to code the severity of any stressor judgedsignificant in the development or exacerbation of a psychiatricdisorder. Codings were based on an assessment of the amountof stress an "average person in similar circumstances and withsimilar sociocultural values would experience." Thus, theseverity rating was based on the stressor and not on a partic­ular individual's vulnerability to that stressor. A severity rangefrom 0 ("unspecified") through 7 ("catastrophic") was pro­vided along with examples of both adult and child/adolescentstressors corresponding to each of the severity ratings.

In DSM-III-R, the distinction between acute (with a dura­tion ofless than 6 months) or predominantly enduring (lastinglonger than 6 months) stressors is introduced. In addition tospecifying all stressors as acute or enduring, the cliniciancalculates the sum severity of all stressors from the previousyear, coding them on a 0 to 6 scalebased again on the amountof stress an "average person would experience."

Axis V of DSM-III was used to code the highest level ofadaptive functioning in the past year. Three major areas wereconsidered: social relationships, occupational functioning(which would be school for children), and the use of leisuretime. In DSM-III-R, the Global Assessment of Functioning(GAF) Scale is to be used for coding, and coding is to bemade for two time periods-current and past year.

Although the authors believe it is appropriate that changeshave been made to the psychosocial axes, they feel thesechanges will have only minimal impact on the problems ofconceptualization, specificity, and reliability that the axeshave.

Space precludes additional specific comparisons of DSM­III and DSM-III-R categories. The above examples haveillustrated some concerns about some of the rather major

530 CANTWELL AND BAKER

changes that have been made between DSM-lII and DSM­lII-R. The ultimate value of these changes will become ap­parent only with additional empirical data.

Conclusions

Toward DSM-IVand ICD-lO

Work on the development of DSM-IV will begin shortly.Work on the development of ICD-IO is already well underway. What are some of the key issues with regard to thedevelopment of these and future systems of classification ofchild and adolescent psychopathology?

A key issue is the degree ofsimilarity between DSM-IVandICD-lO. Kendall (1984) and Spitzer (1984) have opposingviews on this issue. The current draft ofICD-lO (WHO, 1986)reveals significant differences from DSM-I/I-R in the classi­fication of child and adolescent psychopathology. For exam­ple, in the classification of the disruptive behavior disorders,ICD-]0 draft proposes three major subdivisions: hyperkineticdisorder, conduct disorder, and mixed disorder of conductand emotions. Hyperkinetic disorder is then subdivided intosimple disturbance of activity and attention, hyperkineticconduct disorder, and hyperkinetic disorder not otherwisespecified. Conduct disorder is subdivided into conduct disor­der confined to the family context, unsocialized conductdisorder, socialized conduct disorder, and conduct disordernot otherwise specified. The two subdivisions of the categorymixed disorder of conduct and emotions are depressive con­duct disorder and other mixed disorder of conduct and emo­tions.

It can be seen that this proposed ICD-lO classification isvery different from the DSM-II/-R classification. The conductdisorder subtypes are most incompatible. There is no diag­nosis in DSM-II/-R comparable to the ICD-lO subtype "con­duct disorder confined to the family context." The ICD-lOdraft has unsocialized and socialized subtypes based on thepresence ofadequate, lasting friendships with peers of roughlythe same age group. The aggressiveand group subtypes presentin DSM-I/I-R do not exist in the ICD-]0 draft. The depressiveconduct disorder subtype of ICD-lO has no equivalent inDSM-I/I-R, although it could be handled with dual diagnosesof conduct disorder and the appropriate subtype of mooddisorder.

Only empirical data can determine which of these ways ofclassifying the disruptive behavior disorders is more useful. Itis clear, however, that for the DSM and ICD classifications tocorrespond more closely, major revisions will be required.The importance ofa closer correspondence between the DSMand ICD systems cannot now be accurately estimated. Kat­schnig and Simhandl (1986, p. 227) suggest that "psychiatryin its present state of development call ill afford two rivalingpsychiatric compromise classifications." Other researchers(Brockington and Helzer, 1983) have suggested that a poly­diagnostic approach, comparing the validity of different clas­sification systems, will provide the best basis for the establish­ment of the ultimate classification of mental disorder.

It is hoped that DSM-IV and other future classificationsystems will reflect increasingly sophisticated knowledgeabout psychiatric classification of childhood and adolescentpsychopathology. This will require more research in many

areas. For example, categorical methods of classification suchas DSM-Ill and DSM-I/I-R need to be systematically com­pared with alternative methods of classification. Additionalreliability studies are needed to identify the most reliablediagnostic categories. Modifications of diagnostic criteria inthe future should be based on empirical research and not onpersonal statements of opinion or political pressure. We needformal ways of empirically identifying those symptoms thatare necessary for a particular diagnosis to produce the greatestpredictive and construct validity.

Without solid validity studies of the categories in DSM-I/Ior DSM-II/-R, it is not clear whether the increased differen­tiation among disorders is really meaningful. This is particu­larly true for subcategories of disorders such as conduct andattention deficit disorders . Data from published studies dosuggest that the DSM-I/I system provides better differentia­tion than DSM-I/ and probably better coverage of child andadolescent psychopathology. DSM-lII seemed to be acceptedby those raters who used it, and it seemed to be a relativelyeasily learned system, but the feasibility ofDSM-I/I-R has yetto be studied in detail.

If a multiaxial system is to be used, we need to know moreabout how many axes, what is to be coded on the variousaxes, the type of information that each axis should carry, etc.If specific diagnostic criteria are to be used in a system, thereneeds to be more focus on developmental aspects ofsymptom­atology (Cantwell, 1985). It may be that the same disorderwill require different criteria for preschool children, grade­school children, and adolescents.

Despite these problems, the creation of DSM-II/ has hadmajor impact in many areas of psychiatric practice, teaching,and research. It is hoped that in the next decade the data toanswer the major questions that were raised by the introduc­tion of DSM-I/I and DSM-I/I-R will be available.

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