Classification of pervasive developmental disorders: some concepts and practical considerations

Methodological issues in social cognition research in autism spectrum disorder and schizophrenia spectrum disorder: a systematic review

Recent systematic reviews and meta-analyses conclude that similar social cognitive impairments are found in autism spectrum disorder (ASD) and schizophrenia spectrum disorder (SSD). While methodological issues have been mentioned as a limitation, no study has yet explored the magnitude of methodological heterogeneity across these studies and its potential impact for their conclusion. The purpose of this study was to systematically review studies comparing social cognitive impairments in ASD and SSD with a focus on methodology. Following the PRISMA guidelines, we searched all publications on PubMed, PsycINFO, and Embase. Of the 765 studies identified in our data base searches, 21 cross-sectional studies were included in the review. We found significant methodological heterogeneity across the studies. In the 21 studies, a total of 37 different measures of social cognition were used, 25 of which were only used in 1 study. Across studies, the same measure was often said to be assessing different constructs of social cognition - a confusion that seems to reflect the ambiguous definitions of what these measures test in the studies that introduced them. Moreover, inadequate differential diagnostic assessment of ASD samples was found in 81% of the studies, and sample characteristics were markedly varied. The ASD and SSD groups were also often unmatched in terms of medication usage and substance use disorder history. Future studies must address these methodological issues before a definite conclusion can be drawn about the potential similarity of social cognitive impairments in ASD and SSD.

An Explorative Study of Atypical Social Interaction Styles in Adult Men with Autism Spectrum Disorder, Men with Personality Disorders and Men from the General Population

Different atypical social interaction styles (SISs) were defined and tested in children and adolescents with autism spectrum disorder (ASD). Whether these styles can also be distinguished in adults with ASD has not yet been explored. In men with ASD, men with personality disorder (PD), and men from the general population (N = 90), aged 18-65 years, we tested which SISs can be distinguished and how they relate to the presence of PD traits. We found a significant distinction in allocation to atypical SISs between the three groups. This study shows the presence of atypical SISs in adults with ASD, and complements previous SIS findings in children and adolescents with ASD.Trial registration The Netherlands National Trial Register NTR6391. Registered 04 May 2017.

Brain Resting-State Functional Connectivity Is Preserved Under Sevoflurane Anesthesia in Patients with Pervasive Developmental Disorders: A Pilot Study

Functional connectivity studies play a huge role in understanding the relationship between the network connections and the behavioral phenotype of patients with pervasive developmental disorders (PDD). Some patients with PDD may not be able to tolerate the imaging procedure while they are awake, and, hence, they often need general anesthesia. General anesthesia is a confounding factor in functional imaging studies due to its effect on the functional connectivity. The objective of this study is to look at the resting-state functional connectivity (RS-FC) under sevoflurane anesthesia in patients with PDDs. Thirteen adults with PDD scheduled for magnetic resonance imaging (MRI) of the brain under general anesthesia were recruited for the study. Resting-state functional MRI (fMRI) scans were acquired at 1 minimum alveolar concentration (MAC) of sevoflurane. Spontaneous blood oxygenation level-dependent fluctuations were measured, and a seed-voxel analysis was done to identify the resting-state networks. Subjects' data were compared with data from 16 nonanesthetized healthy controls. Six networks (default mode network [DMN], executive control network [ECN], salience network [SN], auditory, visual, and sensorimotor) were investigated. At 1 MAC sevoflurane anesthesia, RS-FC was preserved in all the networks. Secondary analysis of connectivity showed a decrease in connectivity within the thalamus and an increase in DMN-ECN and DMN-SN cross-network connectivity in the anesthetized patient group compared to healthy controls. Previous reports suggested that even mild levels of anesthesia could reduce overall fluctuation levels in the major brain. However, our results provide strong evidence that most networks can sustain detectable levels of activity in patients with PDDs even under deep levels of anesthesia.

The Differentiation between Autism and Asperger Syndrome

In discussing the differentiation between autism and Asperger syndrome, the paper aims to re-examine similarities and differences in symptomatology with reference both to the history of Asperger syndrome and to current research. Symptoms that have been suggested as possibly differential for diagnosis and shared diagnostic features are separately considered. Although the paucity of reliable research findings allows few definitive conclusions to be drawn, it is suggested that attempts to identify subtypes and achieve a greater understanding of the behavioural heterogeneities within autistic spectrum or pervasive developmental disorders is crucial to improving both clinical practice and research.

Questioning the Validity of the Semantic-Pragmatic Syndrome Diagnosis

The classification of developmental language disorders has recently witnessed the birth of a subsyndrome, semantic-pragmatic syndrome, used to describe the case of children with specific language and communication impairments. However, there are striking similar-ities between children with semantic-pragmatic syndrome and those with high-functioning autism on a communicative, behavioural and cognitive level. This article questions the validity of semantic-prag-matic syndrome as a diagnostic concept distinct from high-function-ding autism and, consequently, its use as a clinical entity.

Categorical Approaches to the Diagnosis of Autism

Although autism was first reported in 1943 nearly 40 years elapsed before the disorder was included as an official diagnosis in the American (DSM) classification system. In the last two decades guidelines for the diagnosis of this, and related, conditions have evolved based on a growing body of research. An important recent development has been the convergence of the American (DSM) and International (ICD) diagnostic systems. Although these two official systems differ somewhat in format and intended use, the advent of consistent approaches to the diagnosis of autism will facilitate both research and clinical service. Data that have informed the development of these systems are reviewed and areas of continuing controversy are noted.

Behaviour Profiles within a Population of 145 Children with Autism Using the Behaviour Summarized Evaluation Scale

Clinicians and researchers have observed a degree of heterogeneity within the autistic syndrome which suggests different pathophysiological mechanisms. Greater understanding of this heterogeneity was sought by studying more homogeneous subpopulations according to developmental age (DA) within a large population of children with autism. The sample consisted of 145 children with autism (population P), and two subpopulations were determined according to DA criteria: DA < 2 years, population PDA-; DA? 2 years, population PDA+. An original multivariate descriptive statistical method, correspondence analysis, was applied to 13 behavioural data, followed by a classical hierarchical clustering method. In population P, four behaviour profiles were distinguished on the basis of three main functions: auditory perception, imitation and sensorimotility. The study of more homogeneous subpopulations according to DA revealed differences in the factorial structure of both subpopulations. In population PDA+ the main relevant behaviours defining profiles in autism were first abnormal reactivity to auditory stimuli, followed by imitation deficiences. However in population PDA-the main relevant behaviours were first stereotypies, followed by abnormal reactivity to auditory stimuli. Modification of the organization of behaviours in autism according to developmental age is clarified; unlike the auditory perception dimension, imitation and sensorimotor dimensions may be dependent on development. These results thus support the heterogeneity of the autistic syndrome and clarify some aspects of change and continuity in the expression of the disorders contained in this syndrome.

Autism in flux: a history of the concept from Leo Kanner to DSM-5

In this paper, I argue that a new relation between past and present - a supposed historical continuity in the meaning of autism - is created by the histories written by the discipline itself. In histories of autism written by 'practitioner-historians', a sense of scientific progress and an essentialist understanding of autism legitimize and reinforce current understandings and research directions in the field of autism. Conceptual discontinuities and earlier complexities and disputes concerning classifying and delineating autism are usually left out of the positivist narrative of autism. In an alternative history of the concept of autism, I demonstrate that there have been major shifts in the type of symptoms, signs and impairments that were - and are - thought to be essential and specific for autism.

Toward better recognition of early predictors for autism spectrum disorders

BACKGROUND

Identification and diagnosis of autism spectrum disorders is essentially based on behavioral presentation and developmental history. The current average age at diagnosis is older than 3 years.

METHODS

Over the past 15 years, there has been increasing documentation of the early signs of autism spectrum disorders through both individual retrospective parental reports and screening studies. Recent longitudinal studies have focused on early medical and behavioral features of children regarded at risk, namely younger siblings of children with autism spectrum disorders or children who required neonatal intensive care, with a later diagnosis of autism spectrum disorders.

RESULTS

Potentially useful early neurological signs and developmental predictors for autism spectrum disorders could be identified, with a typical profile that evolved with age.

CONCLUSIONS

Assessment of early social attention and communication skills with adapted scales in children before the age of 18 months in very large community-based settings may lead to high positive predictive values.

Catechol-O-methyltransferase Val158Met polymorphism and hyperactivity symptoms in Egyptian children with autism spectrum disorder

Catechol-O-methyltransferase (COMT) plays an important role in the catabolism of brain dopamine and norepinephrine, which have been implicated in the pathogenesis of Autism spectrum disorder (ASD) as well as in other neuropsychatric disorders. We aimed to investigate the association of COMT Val158Met gene polymorphism with ASD and to examine the influence of such genotypes on hyperactivity symptoms in ASD patients. Eighty ASD patients (mean age 9 ± 1.9 years) and 100 control children (mean age 8.9 ± 1.9 years) were examined. COMT Val58Met polymorphism was genotyped using Tetra-primer ARMS-PCR method. The clinical diagnosis of ASD and ADHD were confirmed according to the DSM-IV criteria for research. We found no significant difference in genotypes or alleles' frequencies of COMT Val158Met polymorphism between ASD patients and control group. There was a significant association between COMT (Val/Val) genotype and both increasing CARS (p=0.001) and hyperactivity scores (p=0.006). Regarding Conner's Score, the DSM-IV hyperactive impulsive were significantly higher in Val/Val genotype than both Met/Val and Met/Met genotypes (p=0.03). Our data suggested an association between COMT Val58Met polymorphism and hyperactivity symptoms in Egyptian children with ASD.

Autism in DSM-5: progress and challenges

BACKGROUND

Since Kanner's first description of autism there have been a number of changes in approaches to diagnosis with certain key continuities . Since the Fourth edition of the Diagnostic and Statistical Manual (DSM-IV) appeared in 1994 there has been an explosion in research publications. The advent of changes in DSM-5 presents some important moves forward as well as some potential challenges.

METHODS

The various relevant studies are summarized.

RESULTS

If research diagnostic instruments are available, many (but not all) cases with a DSM-IV diagnosis of autism continue to have this diagnosis. The overall efficiency of this system falls if only one source of information is available and, particularly, if the criteria are used outside the research context. The impact is probably greatest among the most cognitively able cases and those with less classic autism presentations.

CONCLUSIONS

Significant discontinuities in diagnostic practice raise significant problems for both research and clinical services. For DSM-5, the impact of these changes remains unclear.

Nosology and epidemiology in autism: classification counts

Since its initial description by Kanner in 1943, the criteria by which a diagnosis of autism or autism-like disorders was made--and their alleged etiologies portrayed--have undergone manifold changes, from a psychiatric disorder engendered by "refridgerator" parents to a neurodevelopmental disability produced in the main by genetic abnormalities. In addition, the behavioral characterization of autism has also entered the public consciousness and professional domains increasingly in the past 30 years, the effects of which we are continually coming to terms. A diagnosis of autism that once seemed quite unusual is now considered almost epidemic. Increasing numbers of individuals diagnosed with autism and related pervasive developmental disabilities will, in turn, affect the calculated prevalence of the disorder. In this essay, I attempt to account for the increasing prevalence of autism and autism-related disorders by examining its changing criteria, the individuals and instruments used to make the diagnosis, the reliability and validity of same, and the sample sizes and other aspects of the methodology needed to make an accurate estimate of its prevalence.

Recognizing and treating Rett syndrome in schools

A review of the literature on Rett syndrome (RS) for school-based professionals is presented from a behavioral perspective. A description of RS is provided, including distinctive physical, behavioral, and emotional features, diagnostic criteria for classic and formes frustes forms of RS, and stages of the disorder. The similarities and differences between RS and autism are reviewed. Controversies regarding the classification of RS are presented, including whether RS should be classified as a neurological or psychiatric condition and whether RS should remain classified as a pervasive developmental disorder. Last, a variety of options for the treatment of RS are discussed.

Frequency of symptoms of attention deficit and hyperactivity disorder in autistic children

BACKGROUND: Both DSM-IV and the ICD-10 exclude diagnosis of attention deficit/hyperactivity disorder (ADHD) when autism diagnostic is present. Some authors suggest, however, that autism can be associated to other comorbidity amongst which the ADHD. OBJECTIVE: To estimate prevalence of ADHD in children with autism. METHOD: Children were selected from a specialized school, all of then had previous diagnosis or diagnostic suspicion of autism. The Brazilian version of the KIDDIE-SADS PL was applied to parents for diagnostic of ADHD. DSM-IV diagnostic of autism was based on parents' interview and child observation. RESULTS: 32 children were included in the study. Results show that 53.1% of the ASD child had ADHD symptoms enough to fulfill DSM-IV diagnostic criteria, whereas 56.9% did not fulfill DSM-IV criteria for ADHD. CONCLUSION: Results suggest a high frequency of ADHD symptoms in ASD patients. Elucidating if we are facing a comorbity or an autism distinct phenotype can contribute for a more adjusted pharmacotherapy approach for these children.

[Autism and autistic disorders. Historical and current aspects]

Since its first use in medical literature the meaning of the term autism has constantly changed. An historical overview indicates that in both adult and child psychiatry autism was first used to refer to a symptom of schizophrenia. Later on the use of the term in child psychiatry took a different independent course, which led to present-day conceptualization of autism, mainly due to the work of Leo Kanner and Hans Asperger. Currently autism and autistic disorders are regarded as severe developmental disorders and, due to their stable nature, have gained considerable attention in adult psychiatry. In order to better understand this development, the path from onset to reception is traced via Kanner and Asperger. In the search for central characteristics of autism, one finds restrictions in social communication and interaction, which can be explained by fundamental deficits in social cognition. These restrictions in social cognition can be considered the central characteristic of autism - one which has been a constant since the phenomenon was first described. Our historical review considers to what extent experimental psychopathological research can deepen our understanding of the disorder.

Control of psychomotor agitation and aggressive behavior in patients with autistic disorder: a retrospective chart review

OBJECTIVE: To evaluate the efficacy of pharmacotherapy on the symptoms of psychomotor agitation and aggressive behavior in a sample of patients with autistic spectrum disorder. METHOD: The charts of all patients with a diagnosis of autistic spectrum disorder, receiving care for psychomotor agitation and/or aggressive behavior in two psychiatric outpatient departments between 2001 and 2006, were reviewed. The Clinical Global Impression-Severity and -Improvement scales (CGI-S and CGI-I) were applied to the data retrieved from the charts. RESULTS: The majority of the 26 patients included were treated with second-generation antipsychotics. A positive, statistically significant correlation was found between the implementation of pharmacotherapy and a reduction in CGI-S scores (p<0.05). Treatment response in patients with no mental retardation was better than in those mentally retarded (p<0.05). The majority of patients in whom clinical improvement was found following implementation of treatment had participated in at least one form of intervention therapy in addition to the principal treatment (p<0.05). CONCLUSION: Second-generation antipsychotics seem to reduce psychomotor agitation and aggressive behavior in patients with autistic spectrum disorder; however, further studies are required to evaluate the side effects of these drugs in relation to their beneficial effects.

Autismo: intervenções psicoeducacionais

Há um crescente reconhecimento sobre a importância do tratamento do autismo envolver tanto as necessidades da criança como as da família. No entanto, há controvérsias sobre qual intervenção seria a mais apropriada. Neste artigo, revisaremos a literatura recente sobre as diferentes intervenções que têm sido utilizadas no tratamento do autismo, com ênfase naquelas que possuem base empírica. Não pretendemos discutir em detalhe nenhuma intervenção em particular, mas apresentar uma visão geral sobre os aspectos positivos e as limitações de diferentes intervenções. Concluímos que não há uma abordagem única que seja totalmente eficaz para todas as crianças durante todo o tempo. Ao contrário, argumentamos que as famílias modificam suas expectativas e valores com relação ao tratamento de seus filhos de acordo com a fase de desenvolvimento da criança e do contexto familiar. Em outras palavras, um tipo específico de intervenção pode funcionar bem por certo período (e.g., nos anos anteriores à escolarização) e não funcionar tão bem nos anos subseqüentes (e.g., adolescência). Finalmente, enfatiza-se a importância do diagnóstico e tratamento precoces do autismo.

Executive Functioning in Children with an Autism Spectrum Disorder: Can We Differentiate Within the Spectrum?

The aim of this study was to investigate whether children with high-functioning autism (HFA), Asperger's syndrome (AS), and pervasive developmental disorder not otherwise specified (PDDNOS) can be differentiated from each other and from normal controls on their neurocognitive executive functioning (EF) profile. Children with HFA and AS showed the most EF deficits. The EF profile of the PDDNOS group was more disturbed that the normal control group, but was less disturbed than the profile of the HFA and AS groups. Little difference was found between the three PDD subtypes with respect to EF. This study supports the view that executive dysfunctioning plays an important role in autism. The usefulness of a distinction between different PDD subtypes was not demonstrated.

Parental identification of early behavioural abnormalities in children with autistic disorder

The aim of the study was to identify early behavioural abnormalities in children later diagnosed with autistic disorder. Accurate identification of such deficits has implications for early diagnosis, intervention and prognosis. The parents of 153 children with autistic disorder completed a questionnaire asking them to describe early childhood behaviours of concern and to recall the age of onset. Core deficit-linked behaviours were then identified and the ontogeny of their development was noted. Behaviour categories were: (1) gross motor difficulties, (2) social awareness and play deficits, (3) language and communication difficulties, and (4) unusual preoccupations. The findings supported the notion that the nature and prevalence of these deficits depend on age. Consistent with past research, there was a significant interval between parents first noticing abnormalities and the making of a definitive diagnosis. The implications for this delay are discussed.

The autistic spectrum: subgroups, boundaries, and treatment

There is consensus about the disorders that comprise the autistic spectrum, with autistic disorder, Asperger's disorder, and PDD-NOS as the most typical examples and Rett's disorder and disintegrative disorder as the other components. Important controversies regarding the precise definitions of autistic spectrum disorders and the boundaries between the milder manifestations of those disorders, particularly PDD-NOS, and non-autistic conditions have not been and cannot be resolved fully as long as there is no known biologic cause or consistent biologic or psychological marker. This includes issues as basic as whether the autistic spectrum is a predominantly unitary entity or a collection of more or less similar phenotypes with multiple, varying etiologies. This is why the highest long-term priority in the area of definite diagnosis is the search for biologic marker(s) for autism and related autism spectrum disorders [91]. In the absence of a medical test to unequivocally diagnose autism, definitions of autism and related conditions are based only on manifestations in overt behavior, with all the unreliability this entails. In the future, the discovery of biologic correlates, causes, and pathogenetic pathways will undoubtedly change the way in which autism is diagnosed and lead to a new nosology [95]. Until that time the definitions in the current versions of the classification systems should be considered in a state of evolution. The key problem of the current classification systems is the fact that the boundaries between the various disorders are fuzzy. Instead of a categorical approach, a more useful description might be that of "autistic spectrum disorder," which reflects the range of severity of symptoms. Such a dimensional understanding of PDD is useful to clinicians, who may otherwise use nonspecific terms to avoid the categorical diagnosis of autism [31]. Rutter and Schopler [96] argued for separate clinical and research schemes because clinical and research needs are different. For research purposes it is desirable to have as much direct comparability across studies as possible. The focus is on a high degree of homogeneity within diagnostic groupings. A price must be paid for this detailed specification, and the main cost lies in the proportion of cases left undiagnosed. For example, there may be good scientific reasons for a narrowly defined categorical diagnosis that includes only individuals who definitely and clearly have a specifically defined condition and excludes individuals who may have the condition. For clinicians and educators, classification helps guide the selection of treatments for an individual. From this point of view, broader diagnostic concepts may be most appropriate [95].

[Factor structure of the Autism Diagnostic Interview-Revised (ADI-R): a study of dimensional versus categorical classification of autistic disorders]

OBJECTIVES

This study investigated whether empirically derived dimensions of autistic behavior are consistent with the content-valid construction of the autistic behavior domains according to ICD-10 and DSM-IV (social interaction, communication and repetitive, stereotyped behavior).

METHODS

A principal component exploratory factor analysis routine with varimax-rotation and extraction of factors following the Scree criterion was run using data from the Autism Diagnostic Interview-Revised (ADI-R) of N = 262 individuals exhibiting autism or autistic features.

RESULTS

A three-factor solution consisting of two socio-communicative and one language dimension and accounting for 46.1% of the total variance was found to best describe the data. These factors yielded only vague correspondence with the idea of behavior domains described in ICD-10 and DSM-IV. In addition, factor loadings of items representing repetitive, stereotyped patterns were generally weak.

CONCLUSIONS

The factor-analytic approach to autism indicates a conception of the disorder divergent from that defined in the contemporary psychiatric classification systems, especially regarding the area of repetitive, stereotyped behavior.

A review of subtyping in autism and proposed dimensional classification model

Autism has been divided into subtypes based on social interaction/communication, developmental level, or both. The validity of subtyping systems and the extent to which they overlap were examined. According to this review, a single subtyping system capable of accounting for the symptom heterogeneity in autism has not yet been proposed; however, evidence supports the presence of a three-factor continuum containing at least four subgroups. Foremost among directions for future research is the need for comprehensive studies in which medical screening, careful selection of measures, and longitudinal data collection are included.

Measles-mumps-rubella vaccine and autistic spectrum disorder: report from the New Challenges in Childhood Immunizations Conference convened in Oak Brook, Illinois, June 12-13, 2000

BACKGROUND

Parents and physicians are understandably concerned about the causes and treatment of autism, a devastating disease that affects the entire family. Although much has been learned about autism, there are many gaps in our knowledge about what causes the disorder and how it can be prevented. Autistic symptoms occur along a spectrum, often referred to as autistic spectrum disorder (ASD). Concern has been raised about a possible association between measles-mumps-rubella (MMR) vaccine and inflammatory bowel disease (IBD) and ASD, especially autism with regression. Also, increased requests for educational services related to ASD have raised concerns about possible increases in the incidence of ASD.

METHODS

On June 12-13, 2000, the American Academy of Pediatrics (AAP) convened a conference titled "New Challenges in Childhood Immunizations" in Oak Brook, Illinois. At this conference, parents, practitioners, and scientists presented information and research on MMR vaccine and ASD. Attendees included representatives from select AAP committees and sections as well as federal and other organizations that address related issues. The multidisciplinary panel of experts reviewed data on what is known about the pathogenesis, epidemiology, and genetics of ASD and the available data on hypothesized associations with IBD, measles, and MMR vaccine. Supplemental information was requested from authors who have proposed the hypotheses and other experts in relevant areas.

RESULTS

Autism is a complex disorder of uncertain and probably multiple etiologies. Genetic predisposition to ASD may involve as many as 10 genes. Many experts believe that the abnormal brain development in autism occurs before 30 weeks' gestation in most instances. In utero rubella is a known cause of autism. Animal model data support the biologic plausibility that exposure to yet unrecognized infectious or other environmental agents could cause ASD. Several factors may contribute to apparent increases in incidence of ASD in recent years. Most data indicate increased recognition and reporting as primary factors, but the epidemiologic data are insufficient to determine if there has been a true increase in the incidence of ASD. Increased reporting of ASD in recent years has occurred long after the introduction of MMR vaccine in the United States in 1971 and widespread use of this vaccine in the 1970s for routine immunization of children at 12 to 15 months of age. Appropriate detailed studies are needed to define the true incidence and prevalence of ASD. Epidemiologic studies in Europe indicate no association between MMR vaccine and ASD. Some children with ASD have gastrointestinal symptoms, but an increased rate of any specific gastrointestinal disorder in children with ASD has not been established. Studies to detect evidence of measles virus in intestinal tissue specimens from patients with IBD or autism with gastrointestinal symptoms have not used uniform techniques. Several laboratories have found no evidence of measles viruses in tissue specimens from patients with IBD, but 2 groups have found evidence of measles virus using different techniques. A group that found evidence of measles virus in affected tissue specimens from patients with IBD has also reported detecting portions of measles virus in peripheral blood lymphocytes and intestinal tissue specimens from patients with autism and gastrointestinal disorders. Finding a portion of a virus using molecular techniques does not constitute evidence for a causal relationship, because some viruses persist in unaffected hosts. Additional controlled studies in several laboratories are needed to determine if portions of measles virus persist in intestinal and other tissues of people with and without gastrointestinal disease and/or ASD.

CONCLUSIONS

Although the possible association with MMR vaccine has received much public and political attention and there are many who have derived their own conclusions based on personal experiences, the available evidence does not support the hypothesis that MMR vaccine causes autism or associated disorders or IBD. Separate administration of measles, mumps, and rubella vaccines to children provides no benefit over administration of the combination MMR vaccine and would result in delayed or missed immunizations. Pediatricians need to work with families to ensure that children are protected early in the second year of life from these preventable diseases. Continued scientific efforts need to be directed to the identification of the causes of ASD.

Peripheral auditory asymmetry in infantile autism

Difficulty in filtering relevant auditory information in background noise is one of the features of autism. Auditory filtering processes can be investigated at the peripheral level as they are hypothesized to involve active cochlear mechanisms which are regulated by the efferent activity of the medial olivocochlear (MOC) system. The aim of the present work was therefore to assess these peripheral auditory processes in 22 children and adolescents with autism compared with age- and gender-matched normal controls. Active cochlear mechanisms were evaluated with transiently evoked otoacoustic emissions (TEOAEs) and MOC system efficiency was assessed via TEOAEs which are decreased when stimulating the contralateral ear with noise. The MOC system evaluation was performed on 18 of the 22 children. In both studies, results were analysed according to age (from 4 to 10 years and from 11 to 20 years). The main result concerns the asymmetry of the efferent system which differs in individuals with autism. Several neural processes might be hypothesized as involved in the results obtained as the MOC system which originates in the brainstem received regulating controls from upper brain structures including auditory cortex. Lateralization abnormalities at the auditory periphery may reflect indirectly a problem at a higher level of auditory processing. A second important result shows a decrease in TEOAE amplitude with age, in patients, that may correspond to a decrease in hearing sensitivity.

The children's Social Behavior Questionnaire for milder variants of PDD problems: evaluation of the psychometric characteristics

The Children's Social Behavior Questionnaire (CSBQ) contains items referring to behavior problems seen in children with milder variants of PDD. Data of large samples of children diagnosed as having high-functioning autism, PDDNOS, ADHD, and other child-psychiatric disorders were gathered. Besides the CSBQ, parents completed the Autism Behavior Checklist (ABC) and the Child Behavior Checklist (CBCL). The data provided the basis for scale construction of the CSBQ, a comparison of the CSBQ scales with other instruments and a comparison of groups on scores on the CSBQ. The 5 scales obtained referred to Acting-out behaviors, Social Contact problems, Social Insight problems, Anxious/Rigid behaviors and Stereotypical behaviors. Results show that the CSBQ has good psychometric qualities with respect to both reliability and validity. A comparison of the different groups showed that significant group differences were found on all scales. In general, the autism group received the highest scores, followed by the PDDNOS group and the ADHD group. Exceptions were on the Acting-out scale, where the ADHD group scored highest and on the Social Insight scale, where no significant difference was found between the PDDNOS group and the ADHD group. Implications of the results and suggestions for further research are discussed.

Childhood disintegrative disorder

Childhood disintegrative disorder (CDD) is a clinical syndrome characterized by disintegration of mental functions and regression of acquired language and intellectual functions after a period of normal development typically of 3 to 4 years. Although recognized for many years, research on this condition is less advanced than that in autism. Epidemiological data are limited but the condition is much less common than autism. The relationship of this condition to autism remains the topic of debate. Neuropathological and other medical conditions are sometimes associated with the disorder but contrary to earlier belief this is not typical. Collaborative research would facilitate our understanding of this condition.

Diagnoses commonly missed in childhood. Long-term outcome and implications for treatment

Psychiatric and developmental disorders with onset in early childhood are often missed and commonly overlooked by adult psychiatrists. These disorders have important continuities into adulthood and are powerful predictors of chronicity, comorbidity, and severity. It is essential that they are recognized and taken into account in the assessment and treatment of the adult patient.

Autism and other pervasive developmental disorders: exploring the dimensional view

OBJECTIVE

To examine empirical data on children with autistic disorder (AD), Asperger's disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS) for continuities or distinguishing features between disorder and to see to what extent the Diagnostic and Statistical Manual of Mental Disorder (DSM-IV) diagnostic criteria-reflect observed data.

METHOD

Studies were identified in 4 ways. 1)A Medline search from 1976 to the present of articles with the key words autism, pervasive developmental disorder, autistic spectrum disorder, and Asperger; of these articles, those with mesh headings or textwords "cluster," which identified cluster analyses deriving pervasive developmental disorder (PDD) subtypes, were retained 2) The Journal of Autistic and Developmental Disorder from 1990 to the present was hand-searched to identify other empirically derived studies on diagnosis, prevalence, classification, and validity of PDD subtypes. 3) Key review articles were searched for their references. 4) The references of all identified articles were searched.

RESULTS

Eight cluster studies were retained for their relevance to diagnostic issues, as were 7 empirically derived studies delineating clinic characteristics of children will AD, Asperger's syndrome, or PDD-NOS. Data suggests that children with PDD may fit into 1 of 2 overlapping groups, including a lower-functioning group with greater developmental compromise, social aloofness, and a greater number of autistic symptoms and a higher-functioning group with higher IQ, fewer autistic symptoms, and more prosocial behavior. The PDD subtype resemble each other and can be seen as existing o a continuum, differing only by degree of impairment.

CONCLUSION

Children exhibiting the triad of autistic impairments can be seen as suffering from disorders on a PDD continuum. While the DSM-IV does identify a lower-functioning autistic group (AD), the higher-functioning group is less well served. Asperger's disorder as defined in the DSM-IV is not clearly distinguishable from AD and PDD-NOS, and the PDD-NOS subcategory is not operationalized. Further research is required to elaborate criteria for the higher-functioning PDD group, and measures related to etiology, outcome, and treatment response may help determine which diagnostic criteria can meaningfully separate one disorder from another.

A dimensional classification of autism spectrum disorder by social communication domains

OBJECTIVE

To investigate whether "social communication" could be used to assess severity of symptoms in autism spectrum disorder. Social communication refers to the communication of cognitive and emotional information through facial expression, gesture, and prosody and through implicit understanding of pragmatics and of theory of mind.

METHOD

Subjects were evaluated by raters using the Autism Diagnostic interview-Revised and either the Autism Diagnostic Observation Schedule or the Pre-Linguistic Autism Diagnostic Observation Schedule. Two investigators independently diagnosed autism, Asperger's disorder, or pervasive developmental disorder-not otherwise specified in 63 subjects. Items from the Autism Diagnostic Interview-Revised that were judged to represent social communication behaviors were factor-analyzed.

RESULTS

Three factors were identified: affective reciprocity, joint attention, and theory of mind. Comparing this new classification approach to DSM-IV led to suggestions for possible changes in the latter: (1) Vocabulary and grammar deficiencies in autistic persons should be coded under developmental language disorder, (2) The diagnosis of Asperger's disorder may not be needed. (3) Requiring that all persons with autism spectrum disorder have a symptom from the "restrictive, repetitive, and stereotypic" list may need to be reconsidered.

CONCLUSIONS

The DSM-IV category of pervasive developmental disorder may be ideal for diagnosing "classic" autism, but it may be inadequate for diagnosing less severe forms of the disorder.

Risperidone and explosive aggressive autism

Many autistic patients with mental retardation have difficulties with explosivity and aggression. They often prove resistant to various pharmacotherapeutic interventions. In this study, 11 male outpatients (mean 18.3 years) were administered risperidone in an open-label fashion. The risperidone was started at 0.5 mg daily, and titrated upwards until maximum clinical benefit occurred. Serial clinical interviews were conducted, and Conners Parent-Teacher Questionnaires (short form) were completed by the caretakers. Substantial clinical improvement was noted almost immediately in each patient, with aggression, self-injury, explosivity, and poor sleep hygiene most improved. The modal dose for optimal response was 0.5 mg bid. Weight gain was a significant side effect (average velocity of 0.47 kg per week), while none of the patients experienced extrapyramidal side effects.

Pedantic speaking style differentiates Asperger syndrome from high-functioning autism

Asperger syndrome (AS) is a pervasive developmental disorder recently introduced as a new diagnostic category in the ICD-10 and the DSM-IV. Along with motor clumsiness, pedantic speech has been proposed as a clinical feature of AS. However, few attempts have been made to define and measure this symptom. We studied 17 patients with AS (ICD-10; 14 male, 3 female; mean age 16.4 years, mean full-scale IQ 97) and compared them with a control group of 13 patients with normal-intelligence autism or high-functioning autism (HFA) (ICD-10/DSM-III-R; 12 male, 1 female; mean age 15.5 years, mean full-scale IQ 81.2). An operational definition of pedantic speech was formulated and a rating scale devised. 13 (76%) of the AS patients were rated as pedantic compared to 4 (31%) of the HFA group (chi 2 = 6.3; p = .01). Results suggest that pedantic speech is common in AS and may help differentiate AS from high-functioning autism.

Changing criteria of autistic disorders: a comparison of the ICD-10 research criteria and DSM-IV with DSM-III-R, CARS, and ABC

Revised versions of diagnostic manuals, the International Classification of Diseases (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) all operate with several subgroups in the autistic spectrum. Five of the subgroups are identical in the two manuals, but ICD-10 contains five in addition. 132 children were diagnosed using ICD-10, DSM-IV, DSM-III-R, the Childhood Autism Rating Scale (CARS), and the Autistic Behavior Checklist (ABC). Five out of ten alternative subgroups of Pervasive Developmental Disorders (PDD) were identified in a population of developmentally impaired children. These subgroups were the same in the two manuals; the additional ones in ICD-10 were not identified. With the exception of the groups Disintegrative Disorder and Rett syndrome, significant differences were found between all the subgroups within the PDD spectrum and between the PDD group and the non-PDD group. Some problems connected with the guidelines in the ICD-10 manual are discussed.

Cumulative incidence and prevalence of childhood autism in children in Japan

BACKGROUND

An epidemiological survey of childhood autism as defined in ICD-10 Research Criteria was conducted in the northern part of Yokohama, Japan.

METHOD

The routine health checkup for 18-month-old children served as the initial mass-screening, and all facilities which provide child care services function to detect all cases with childhood autism and refer them to the Yokohama Rehabilitation Centre.

RESULTS

Cumulative incidence of childhood autism up to 5 years of age among the birth cohort of 1988, and prevalence on 1 January 1994, among residents born in 1988 were estimated

RESULTS

Cumulative incidence and prevalence were 16.2 per 10,000 and 21.1 per 10,000, respectively. Children with high-functioning autism who had IQs of 70 and over constituted approximately half of all the children with childhood autism. CONCLUSION. It was confirmed through better detection of high-functioning cases that childhood autism in Japan is more common than formerly estimated.

The validity and reliability of the Wing Subgroups Questionnaire

This study examined the validity and the internal and interrater reliability of the Wing Subgroups Questionnaire (WSQ), an assessment that classifies children with autism into one of three subtypes. Subjects were 42 students enrolled in multihandicapped special education classrooms. Results indicated that items pertaining to the active-but-odd and the aloof subtypes, and to typical development, demonstrated good consistency, whereas passive subtype items showed moderate consistency. Interrater reliability was good for all subtypes utilizing intraclass correlations, but it was moderate with regard to percentage agreement of subtype diagnosis. Interscale correlations were mostly low or negative, suggesting that the subtype scales are measuring distinct constructs. Significant differences among the subtypes were found on three measures of communication, three measures of social interaction, two measures of stereotypic behavior, and one measure of temper/aggression.

Autism research: prospects and priorities

Research prospects and priorities in the field of autism are discussed with respect to (a) diagnosis, classification, and epidemiology; (b) clinical research; (c) neuropsychological research; (d) genetics; (e) structural and functional brain imaging; (f) postmortem studies; (g) other biological research; and (h) treatment research. Also, it is argued that research into autism has a priority in the broader field of developmental psychopathology because it carries the promise of throwing light on casual mechanisms that apply beyond the syndrome of autism.

Diagnosis and classification in autism

This study compared four systems for the diagnosis of autism (DSM-III, DSM-III-R, DSM-IV, and ICD-10) with two empirically derived taxa of autism, and with three social subgroups of autism (Aloof, Passive, and Active-but-Odd) in 194 preschool children with salient social impairment. There were significant behavior and IQ differences between autistic and other-PDD groups for all four diagnostic systems, and a significant association was found (a) for Taxon B, diagnoses of autism, and the Aloof subgroup, and (b) for Taxon A, other-PDD, and the Active-but-Odd subgroup. Findings offer support for two major overlapping continua within idiopathic Pervasive Developmental Disorder.

Empirically derived subtypes of pervasive developmental disorders: a cluster analytic study

A cluster analytic study was conducted to empirically derive behaviorally homogeneous subtypes of pervasive developmental disorders (PDD). Subjects were clustered based on a broad range of behavioral symptoms which characterize autism. Behavioral variables were measured using several of the standardized psychometric instruments most commonly employed in assessing autistic individuals. The cluster solution indicated the presence of four distinct groups. Validity checks generally confirmed significant between-group differences on independent measures of social, language, and stereotyped behaviors. In addition, the four-group cluster solution was compared to previously developed typological systems of PDD (i.e., subcategories based on IQ early onset, styles of social interaction, and DSM-III-R diagnosis). Results generally supported both the behavioral homogeneity of the four subgroups and also several important between-group differences. The potential utility of using cluster analyses to explore subtypes of PDD is discussed.

The Landau-Kleffner Syndrome: a review

The Landau-Kleffner syndrome or the syndrome of acquired epileptic aphasia was first described in 1957. The disorder is characterised by gradual or rapid loss of language in a previously normal child. All children have abnormal EEG compatible with the diagnosis of epilepsy, however, only 70% have clinical seizures. The present article presents a review of the current knowledge concerning this disorder. Information is provided related to the clinical picture, etiology, pathogenesis, treatment and outcome.

Issues in the taxonomy of psychopathology in mental retardation

Several factors appear to impede the development of a valid taxonomy of psychopathology in children and adolescents with mental retardation. These include (a) the lack of a widely accepted definition of psychopathology in mental retardation, (b) disagreement on the nature of the relationship between mental retardation and psychopathology, and (c) insufficient evidence for the reliability and validity of current DSM or ICD systems in this population. In this article, we offer a definition of psychopathology in children with mental retardation; review concepts of the relationship between psychopathology and mental retardation; argue that in moving toward a valid taxonomy factors to be considered should include data from multivariate studies, findings related to behavior phenotypes, and diagnostic considerations with stereotypic behavior and self-injury, organic brain syndromes and pervasive developmental disorders. Finally, we outline a research strategy that may serve as a useful framework for developing a valid taxonomy of psychopathology in this population.

Language and communication in autistic disorders

Communication problems form one of the key diagnostic criteria for autism, but there is a wide variety of manifestations. The theory that autistic individuals are unable to represent mental states can shed light on both the nature and range of communication impairments. This theory predicts that the specific communication deficit lies in the use of language to affect other minds. Language is not special in this respect, and is important only in so far as it may be used to give evidence of a speaker's thoughts and intentions. Thus, in autism, language level would be expected to relate strongly to performance on standard tests of theory of mind. Normal language acquisition appears to build upon the ability to recognize and orient towards ostensive behaviour. For this reason, it may not be necessary to postulate additional language impairments in order to explain the almost universal prevalence of language delay in children with autism. Autism, then, provides a model for studying the important distinction between language and communication, and demonstrates the vital part which mind-reading plays in normal human verbal and non-verbal interaction.

Psychiatric genetics: research challenges and pathways forward

Lessons from past psychiatric genetic research, together with key issues in psychiatry requiring genetic investigation, are reviewed in order to consider the implications for the ways forward. It is argued that traditional quantitative genetics needs to use a combination of twin, adoptee, and family strategies, to examine continuities and discontinuities in psychopathology between childhood and adult life, to compare dimensions and categories, to employ adequate conceptualization and measurement of disorders, to use statistical techniques based on latent constructs, to use biological trait indicators where possible, to examine risk factors as well as diseases, to include good measures of postulated environmental risk variables, to study the interplay between genes and environment, and to study the key assumptions underlying genetic strategies. Molecular cytogenetics needs to consider both the general and specific psychopathological risks associated with chromosome abnormalities and to examine the mechanism involved, to examine the role of submicroscopic chromosomal deletions and of mitochondrial disorders, and to investigate the mechanisms involved in trinucleotide repeat amplifications that take place during intergenerational transmission. Molecular genetics needs to make greater use of smaller pedigrees in view of the concerns over phenotypic definition and genetic heterogeneity in very large extended dense pedigrees, to use sib-pair designs in view of the likelihood that most psychiatric disorder will prove to be multifactorial, to combine association strategies with linkage analyses, to pay careful attention to the definition of phenotypes in probands, to remain in close touch with other branches of biological psychiatry, and to make effective use of collaboration between centers. To date, transgenic models have had a rather limited application in psychiatry but, despite their difficulties, they are likely to provide an underpinning for gene therapy in disorders where that seems feasible.

Is fragile X syndrome a pervasive developmental disability? Cognitive ability and adaptive behavior in males with the full mutation

In addition to mental retardation (MR), fragile X [fra(X)] syndrome has been associated with various psychopathologies, although it appears that the link is secondary to MR. It has been proposed that individuals with the full mutation be classified as a subcategory of pervasive developmental disorders (PDD). If fra(X) males are to be categorized as PDD, how do they compare with other types of developmental disabilities? We examined 27 fra(X) males aged 3-14 years, from 4 sites in North America. Measures of cognitive abilities were obtained from the Stanford-Binet Fourth Edition (SBFE), while levels of adaptive behavior were evaluated using the Vineland Adaptive Behavior Scales (VABS). Control subjects were sex-, age-, and IQ matched children and adolescents ascertained from the Developmental Evaluation Clinic (DEC) at Kings County Hospital. At the DEC, control subjects were diagnosed as either MR (n = 43) or autistic disorder (AD; n = 22). To compare subjects' adaptive behavior (SQ) with their cognitive abilities (IQ), a ratio of [(SQ/IQ) x 100] was computed. Results graphed as cumulative distribution functions (cdf) revealed that the cdf for AD males, who by definition are socially impaired, was positioned to the left of the cdf for MR controls, as expected. Mean ratio for AD males (70) was lower than for MR males (84). On the other hand, the cdf for fra(X) males was positioned far to the right of either AD or MR controls (mean ratio = 125). Statistical tests showed that SQ of fra(X) males was significantly higher than controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetics of autism: characteristics of affected and unaffected children from 37 multiplex families

Evidence from twin and family studies strongly suggests that genetic factors play a prominent role in the etiology of some cases of infantile autism. Genetic factors would be expected to be especially strong in families with multiple autistic members (multiplex families). This report describes the identification and evaluation of 44 families with two or more autistic children collected as part of a genetic linkage study in autism. Families were referred with a presumptive classification of multiplex autism. Children referred as autistic, as well as their presumptively normal siblings, were assessed using the Autism Diagnostic Interview (ADI) and the Autism Diagnostic Observation Scale (ADOS). Thirty-seven of the 44 families (87%) had at least two children who met diagnostic criteria for autism on the ADI. Of the total group of 117 children evaluated in those families, 83 (71%) met all ADI criteria and could be unambiguously classified as autistic (affected), 26 (22%) met none of the ADI criteria and were classified as not autistic (unaffected), and 8 (7%) were classified as uncertain because they met one or more but not all of the ADI cutpoints. Autistic siblings were not significantly concordant for most autism characteristics, for IQ, or for verbal ability. Significant concordances were found, however, for behaviors related to rituals and repetitive play, and for social impairments in the expression and understanding of facial expressions of emotion.(ABSTRACT TRUNCATED AT 250 WORDS)