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Background: Epidemiological studies infancy predictors of mental disorders are scarce., Methods: The study is part of a longitudinal birth-cohort study, The Copenhagen Child Cohort CCC2000. Infant mental health and development and mother-infant relations were assessed by community health nurses from birth to age 10 months. Data on the perinatal period were obtained from Danish National Registers. Mental health outcome at age 5-7 years was investigated in 1,585 children who were assessed by the Developmental and Well-Being Assessment (DAWBA) and diagnosed according to the ICD-10., Results: Predictors of autism spectrum disorders were problems of oral-motor development OR 5.02 (95% CI: 1.63-15.42) and overall development OR 4.24 (95% CI: 1.35-13.33). A deviant pattern of activity and interests were predictive of autism spectrum disorder, OR 5.34 (95% CI 1.45-19.70) and hyperkinetic disorder, OR 4.71 (95% CI: 1.28-17.39). Hyperkinetic disorder was furthermore predicted by mother-infant relationship problems, OR 8.07 (95% CI: 2.90-22.47). The significant associations between infant developmental problems and autism spectrum disorders persisted in multiple logistic regression analyses controlled for maternal psychological problems and mother-infant relationship problems, OR 3.21 (95% CI: 1.09-9.45). Mother-infant relationship problems remained strongly associated to hyperkinetic disorders in the multivariate analyses controlled for child development problems and maternal psychological problems, OR 5.20 (95% CI: 1.55-17.47). No significant infancy predictors were found regarding emotional and behavioural disorders at age 5-7 years., Conclusion: Predictors of autism spectrum/pervasive developmental disorders and hyperkinetic disorders at child age 5-7 years were identified between birth and child age 10 months in community health settings. The study results suggest potential areas of early preventive intervention, which have to be further explored regarding the psychometric qualities of the identification of infants at risk, and concerning methods to handle and intervene towards these children in the general child health surveillance., (© 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.)

A group of children presents with a rather peculiar type of oppositional behaviours, sometimes now subsumed under the label of 'pathological demand avoidance' syndrome, also increasingly referred to as PDA. Boys and girls with 'this kind of PDA' will do anything to avoid meeting demands of adults and children alike. The behaviours 'used' in maintaining avoidance range from openly oppositional or manipulative to 'extreme shyness', passivity and muteness. These behaviours in terms of expression of affection are rather the opposite of those associated with the commonly used meaning of PDA. However, the avoidant behaviour is quite often 'publicly displayed' and with no feeling for the inappropriateness of the, sometimes even, exhibitionist style of extreme demand avoidance (EDA). The 'disorder' was first heard of in 1980, when Elisabeth Newson presented the first 12 cases of what she believed to be a 'new' and separate syndrome and that she referred to as PDA. Even though PDA has attracted quite a bit of clinical attention in the United Kingdom and other parts of Europe (including Scandinavia), virtually no research has been published in the field so far (Newson, Le Maréchal, & David, ). Experienced clinicians throughout child psychiatry, child neurology and paediatrics testify to its existence and the very major problems encountered when it comes to intervention and treatment. It is therefore a major step forward that O'Nions and co-workers (this issue) have developed a new 'trait measure' for PDA ('the EDA-Q'), a measure that appears to hold considerable promise for research, and eventually for clinical practice., (© 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.)

Background: Pathological Demand Avoidance (PDA) is a term increasingly used in the United Kingdom to describe children who obsessively resist everyday demands, going to extreme lengths to avoid these. There is debate about its relationship with both autism spectrum disorder (ASD) and oppositional defiant disorder (ODD). Unlike ASD, children with PDA are said to use socially manipulative avoidance strategies; and unlike ODD, they resort to extreme, embarrassing or age-inappropriate behaviour. To date, there has been little research into PDA, and it remains contentious. Currently, there are no questionnaire instruments available to aid consistency in description. This study reports the development and preliminary validation of the 'Extreme Demand Avoidance Questionnaire' (EDA-Q), designed to quantify PDA traits based on parent-reported information., Methods: The validation study involved data from 326 parents of children aged 5-17 allocated to six groups based on information reported by parents about received diagnoses and behavioural difficulties: (a) typically developing children (N = 102), (b) children with ASD without disruptive behaviour (N = 36), (c) children with ASD with disruptive behaviour (N = 48), (d) children for whom PDA was suspected by parents (irrespective of other diagnoses) (N = 67), (e) children who had, according to parents, been identified as having PDA by a health professional, irrespective of other diagnoses (N = 50), and (6) disruptive behaviour or behavioural problems without suspected/identified ASD or PDA (N = 23)., Results: Although the Strengths and Difficulties Questionnaire (SDQ) did not differentiate PDA from those with ASD plus disruptive behaviour; score on the EDA-Q was significantly higher in PDA than all comparison groups. ROC analysis indicated good sensitivity (.80) and specificity (.85). Across all case groups, females scored higher than males on the EDA-Q. Separate cut-off scores were identified for older and younger age-groups., Conclusions: Our findings highlight the potential utility of the EDA-Q to assist the identification of this unusual profile for future research., (© 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.)

Background: Intraindividual variability in reaction time (RT) has received extensive discussion as an indicator of cognitive performance, a putative intermediate phenotype of many clinical disorders, and a possible trans-diagnostic phenotype that may elucidate shared risk factors for mechanisms of psychiatric illnesses., Scope and Methodology: Using the examples of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD), we discuss RT variability. We first present a new meta-analysis of RT variability in ASD with and without comorbid ADHD. We then discuss potential mechanisms that may account for RT variability and statistical models that disentangle the cognitive processes affecting RTs. We then report a second meta-analysis comparing ADHD and non-ADHD children on diffusion model parameters. We consider how findings inform the search for neural correlates of RT variability., Findings: Results suggest that RT variability is increased in ASD only when children with comorbid ADHD are included in the sample. Furthermore, RT variability in ADHD is explained by moderate to large increases (d = 0.63-0.99) in the ex-Gaussian parameter τ and the diffusion parameter drift rate, as well as by smaller differences (d = 0.32) in the diffusion parameter of nondecision time. The former may suggest problems in state regulation or arousal and difficulty detecting signal from noise, whereas the latter may reflect contributions from deficits in motor organization or output. The neuroimaging literature converges with this multicomponent interpretation and also highlights the role of top-down control circuits., Conclusion: We underscore the importance of considering the interactions between top-down control, state regulation (e.g., arousal), and motor preparation when interpreting RT variability and conclude that decomposition of the RT signal provides superior interpretive power and suggests mechanisms convergent with those implicated using other cognitive paradigms. We conclude with specific recommendations for the field for next steps in the study of RT variability in neurodevelopmental disorders., (© 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.)

Background: The range of outcomes for young adults with Autism Spectrum Disorders (ASD) and the early childhood factors associated with this diversity have implications for clinicians and scientists., Methods: This prospective study provided a unique opportunity to predict outcome 17 years later for a relatively large sample of children diagnosed with ASD at 2 years old. Diagnostic and psychometric instruments were administered between 2 and 19 with data from 2, 3, and 19 included in this study. Clinicians administered tests without knowledge of previous assessments whenever possible. Caregivers provided additional information through questionnaires., Results: Significant intellectual disabilities at 19 were predicted by age 2 about 85% of the time from VIQ and NVIQ scores together, though prediction of young adult outcome for youths with average or higher intelligence was more complex. By 19, 9% of participants had largely overcome core difficulties associated with ASD and no longer retained a diagnosis. These youths with Very Positive Outcomes were more likely to have participated in treatment and had a greater reduction in repetitive behaviors between age 2 and 3 compared to other Cognitively Able youths (VIQ ≥70) with ASD. Very Positive Outcome youths did not differ phenotypically from Cognitively Able ASD individuals at 2 but both groups differed from Cognitively Less Able individuals (VIQ <70)., Conclusion: Those most at risk for intellectual disabilities and ASD can be reliably identified at an early age to receive comprehensive treatment. Findings also suggest that some cognitively able children with ASD who participate in early intervention have very positive outcomes, although replication with randomized, larger samples is needed. In order to improve understanding of very positive outcomes in ASD, future research will need to identify how variations in child characteristics and environmental factors contribute to the nature and timing of growth across individuals and areas of development., (© 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.)

Background: The Autism Diagnostic Interview-Revised (ADI-R) is a gold standard assessment of Autism Spectrum Disorder (ASD) symptoms and behaviours. A key underlying assumption of studies using the ADI-R is that it measures the same phenotypic constructs across different populations (i.e., males/females, younger/older, verbal/nonverbal). The objectives of this study were to evaluate alternative measurement models for the autism symptom phenotype based on the ADI-R algorithm items and to examine the measurement equivalence of the most parsimonious and best fitting model across subgroups of interest., Methods: Data came from the Autism Genome Project consortium and consisted of 3,628 children aged 4-18 years (84.2% boys and 75% verbal). Twenty-eight algorithm items applicable to both verbal and nonverbal participants were used in the analysis. Measurement equivalence of the autism phenotype was examined using categorical confirmatory factor analysis., Results: A second-order model resembling the proposed DSM-5 two-factor structure of the phenotype showed good overall fit, but not for all the subgroups. The autism symptom phenotype was best indexed by the first-order, six-factor measurement model proposed by Liu et al. (2011). This model was well fitting and measurement equivalent across subgroups of participants (age, verbal ability and sex)., Conclusions: The autism symptom phenotype is adequately characterized by a six-factor measurement model; this model appears to be measurement equivalent across subgroups of children and youth with ASD that differ in age, sex and verbal ability. The two-factor model provides equally good fit for the sample as a whole, but comparison of these two dimensions between subgroups that might differ in terms of age, sex or verbal ability is challenged by lack of measurement equivalence., (© 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.)

Background: Introduction of proposed criteria for DSM-5 Autism Spectrum Disorder (ASD) has raised concerns that some individuals currently meeting diagnostic criteria for Pervasive Developmental Disorder (PDD; DSM-IV-TR/ICD-10) will not qualify for a diagnosis under the proposed changes. To date, reports of sensitivity and specificity of the new criteria have been inconsistent across studies. No study has yet considered how changes at the 'sub domain' level might affect overall sensitivity and specificity, and few have included individuals of different ages and ability levels., Methods: A set of DSM-5 ASD algorithms were developed using items from the Diagnostic Interview for Social and Communication Disorders (DISCO). The number of items required for each DSM-5 subdomain was defined either according to criteria specified by DSM-5 (Initial Algorithm), a statistical approach (Youden J Algorithm), or to minimise the number of false positives while maximising sensitivity (Modified Algorithm). The algorithms were designed, tested and compared in two independent samples (Sample 1, N = 82; Sample 2, N = 115), while sensitivity was assessed across age and ability levels in an additional dataset of individuals with an ICD-10 PDD diagnosis (Sample 3, N = 190)., Results: Sensitivity was highest in the Initial Algorithm, which had the poorest specificity. Although Youden J had excellent specificity, sensitivity was significantly lower than in the Modified Algorithm, which had both good sensitivity and specificity. Relaxing the domain A rules improved sensitivity of the Youden J Algorithm, but it remained less sensitive than the Modified Algorithm. Moreover, this was the only algorithm with variable sensitivity across age. All versions of the algorithm performed well across ability level., Conclusions: This study demonstrates that good levels of both sensitivity and specificity can be achieved for a diagnostic algorithm adhering to the DSM-5 criteria that is suitable across age and ability level., (© 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.)

Background:   Recent models of the early emergence of autism spectrum disorder (ASD) propose that infant intrinsic risk susceptibilities in behaviour may be amplified by interaction within the early social environment into an increasingly atypical developmental trajectory. This study examines whether 6- and 12-month parent-infant interactions in at-risk siblings differ from those with low-risk and whether--in at-risk siblings--such interactions predict later 3-year classification of ASD or no ASD., Method:   Within the British Autism Study of Infant Siblings (BASIS), 6-min videotaped episodes of parent-infant free play in infants at 6-10 months (45 at-risk siblings and 47 low-risk siblings) and 12-15 months (43 at-risk siblings and 48 low-risk siblings) in a laboratory setting were rated on the Manchester Assessment of Caregiver-Infant Interaction (MACI), blind to participant information. Standard tests were administered for concurrent behavioural signs of ASD features and developmental level. Systematic consensus diagnostic classification of ASD was made at 3 years for the at-risk siblings., Results:   Parent nondirectiveness and sensitive responsiveness differed in relation to ASD/risk status (at-risk ASD, at-risk no-ASD and low-risk) at both 6 and 12 months. At 6 months, infant liveliness was lower in the at-risk groups; at 12 months, infant attentiveness to parent and positive affect were lower in the at-risk group later diagnosed with ASD. Dyadic mutuality and intensity of engagement showed a group effect at 12 months. Dyadic mutuality, infant positive affect and infant attentiveness to parent at 12 months (but not 6 months) predicted 3-year ASD outcome, whereas infant ASD-related behavioural atypicality did not., Conclusions:   This is the first prospective evidence that early dyadic interaction between at-risk infants and their parents is associated with later diagnostic outcome in ASD. Possible explanations for these findings and their theoretical implications are considered., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background:  The sociocommunicative problems in autism spectrum disorder (ASD) are traditionally linked to impairments in theory of mind (ToM), the ability to ascribe mental states to others. Although ToM impairments are consistently reported in young children with ASD, findings on more advanced ToM understanding in older individuals with high-functioning ASD (HFASD) are less straightforward. Therefore, we assessed the advanced ToM abilities of a large sample of school-aged children and adolescents with HFASD (n = 194; 6-20 years) and compared them to a typically developing (TD) comparison group (n = 60)., Methods: Participants' advanced ToM was assessed with five social stories containing second-order false beliefs, display rules, double bluff, faux pas, and sarcasm., Results: Participants with HFASD performed equally well on each of the ToM stories as their TD peers. Consistent age effects were noticed with adolescents outperforming the children. Furthermore, advanced ToM was positively associated with participants' age, verbal abilities, and general reasoning abilities., Conclusions: Counter to what the ToM theory of ASD would predict, school-aged children and adolescents with HFASD seem to be able to master the theoretical principles of advanced mental state reasoning. However, they may still fail to apply these theoretical principles during everyday social interactions., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background: The attentional blink (AB) phenomenon was used to assess the effect of emotional information on early visual attention in typically developing (TD) children and children with autism spectrum disorders (ASD). The AB effect is the momentary perceptual unawareness that follows target identification in a rapid serial visual processing stream. It is abolished or reduced for emotional stimuli, indicating that emotional information has privileged access to early visual attention processes., Methods: We examined the AB effect for faces with neutral and angry facial expressions in 8- to 14-year-old children with and without an ASD diagnosis., Results: Children with ASD exhibited the same magnitude AB effect as TD children for both neutral and angry faces., Conclusions: Early visual attention to emotional facial expressions was preserved in children with ASD., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background: Although a diagnosis of autism spectrum disorder (ASD) appears to be stable in children as young as age three, few studies have explored stability of a diagnosis in younger children. Predictive value of diagnostic tools for toddlers and patterns of symptom change are important considerations for clinicians making early diagnoses. Most findings come from high-risk samples, but reports on children screened in community settings are also needed., Methods: Stability of diagnosis and Autism Diagnostic Observation Schedule – Toddler Module (ADOS-T) classifications and scores was examined across two time points in a sample of 82 children identified through the FIRST WORDS Project.Children received two comprehensive diagnostic evaluations at average ages of 19.39 (SD = 2.12) and 36.89 (SD = 3.85) months., Results: Stability was 100% when confirming and ruling out a diagnosis of ASD based on a comprehensive diagnostic evaluation that included clinic and home observations,although diagnosis was initially deferred for 17% of the sample. Receiver Operating Characteristic curves revealed excellent sensitivity and acceptable specificity for the ADOS-T compared to concurrent diagnosis. Logistic regressions indicated good predictive value of initial ADOS-T scores for follow-up diagnosis. Finally, both ASD and Non-ASD children demonstrated a decrease in Social Affect scores (i.e.,improvement), whereas children with ASD demonstrated an increase in Restricted and Repetitive Behavior scores (i.e., worsening), changes that were accounted for by nonverbal developmental level in mixed model analyses., Conclusions: Short-term stability was documented for children diagnosed at 19 months on average, although a minority of children initially showed unclear diagnostic presentations.Findings highlight utility of the ADOS-T in making early diagnoses and predicting follow-up diagnoses. Children with ASD demonstrated improvement in social communication behaviors and unfolding of repetitive behaviors, suggesting that certain early patterns of change in symptoms may be characteristic of ASD., Keywords: Autism spectrum disorder, developmental delay, diagnosis, development,assessment.

Background: The Social Responsiveness Scale (SRS) is a parent-completed screening questionnaire often used to measure autism spectrum disorders (ASD) severity. Although child characteristics are known to influence scores from other ASD-symptom measures, as well as parent-questionnaires more broadly, there has been limited consideration of how non-ASD-specific factors may affect interpretation of SRS scores. Previous studies have explored effects of behavior problems on SRS specificity, but have not addressed influences on the use of the SRS as a quantitative measure of ASD-symptoms., Method: Raw scores (SRS-Raw) from parent-completed SRS were analyzed for 2,368 probands with ASD and 1,913 unaffected siblings. Regression analyses were used to assess associations between SRS scores and demographic, language, cognitive, and behavior measures., Results: For probands, higher SRS-Raw were associated with greater non-ASD behavior problems, higher age, and more impaired language and cognitive skills, as well as scores from other parent report measures of social development and ASD-symptoms. For unaffected siblings, having more behavior problems predicted higher SRS-Raw; male gender, younger age, and poorer adaptive social and expressive communication skills also showed small, but significant effects., Conclusions: When using the SRS as a quantitative phenotype measure, the influence of behavior problems, age, and expressive language or cognitive level on scores must be considered. If effects of non-ASD-specific factors are not addressed, SRS scores are more appropriately interpreted as indicating general levels of impairment, than as severity of ASD-specific symptoms or social impairment. Additional research is needed to consider how these factors influence the SRS' sensitivity and specificity in large, clinical samples including individuals with disorders other than ASD., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background: Autism spectrum disorder (ASD) is characterized by notable phenotypic heterogeneity, which is often viewed as an obstacle to the study of its etiology, diagnosis, treatment, and prognosis. On the basis of empirical evidence, instead of three binary categories, the upcoming edition of the DSM 5 will use two dimensions - social communication deficits (SCD) and fixated interests and repetitive behaviors (FIRB) - for the ASD diagnostic criteria. Building on this proposed DSM 5 model, it would be useful to consider whether empirical data on the SCD and FIRB dimensions can be used within the novel methodological framework of Factor Mixture Modeling (FMM) to stratify children with ASD into more homogeneous subgroups., Methods: The study sample consisted of 391 newly diagnosed children (mean age 38.3 months; 330 males) with ASD. To derive subgroups, data from the Autism Diagnostic Interview-Revised indexing SCD and FIRB were used in FMM; FMM allows the examination of continuous dimensions and latent classes (i.e., categories) using both factor analysis (FA) and latent class analysis (LCA) as part of a single analytic framework., Results: Competing LCA, FA, and FMM models were fit to the data. On the basis of a set of goodness-of-fit criteria, a 'two-factor/three-class' factor mixture model provided the overall best fit to the data. This model describes ASD using three subgroups/classes (Class 1: 34%, Class 2: 10%, Class 3: 56% of the sample) based on differential severity gradients on the SCD and FIRB symptom dimensions. In addition to having different symptom severity levels, children from these subgroups were diagnosed at different ages and were functioning at different adaptive, language, and cognitive levels., Conclusions: Study findings suggest that the two symptom dimensions of SCD and FIRB proposed for the DSM 5 can be used in FMM to stratify children with ASD empirically into three relatively homogeneous subgroups., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background: Longitudinal research studies have demonstrated that experienced clinicians using standardized assessment measures can make a reliable diagnosis of autism spectrum disorders (ASDs) in children under age 3. Limited data are available regarding the sensitivity and specificity of these measures in community settings. The aims of this study were to determine how well a standardized diagnostic observational measure (Autism Diagnostic Observation Schedule - ADOS) functions alone, and with a brief parent measure within a community setting when administered by community clinicians., Methods: Clinical records for 138 children between the ages of 24 and 36 months of age who were evaluated for possible ASD or social/language concerns at a hospital-based developmental evaluation clinic were examined. Evaluations were conducted by community-based clinical psychologists. Classification results obtained from standardized diagnostic measures were compared with case reviewer diagnosis, by reviewers blind to scores on diagnostic measures, using The Records-based Methodology for ASD Case Definition that was developed by the Metropolitan Atlanta Developmental Disabilities Surveillance Program., Results: When compared with case review diagnosis, the ADOS demonstrated strong sensitivity and specificity for both Autism versus Not Autism and ASD versus Nonspectrum (NS) diagnoses in this young sample. The Social Communication Questionnaire (SCQ), using the lower cutoff of ≥12, had adequate sensitivity when differentiating Autism from Not Autism, but weak sensitivity when differentiating ASD from NS, missing about 80% of the children with pervasive developmental disorder - not otherwise specified. Using either the Modified Checklist for Autism in Toddlers or the SCQ in combination with the ADOS did not result in improved specificity over the ADOS alone and led to a drop in sensitivity when differentiating ASD from NS disorders., Conclusions: These results demonstrate that following best practice guidelines, the ADOS can be successfully incorporated into clinical practice with relatively good sensitivity and specificity, and worked well with a referred sample of 2-year-olds. A parent questionnaire did not lead to any improvement in diagnostic classification above the ADOS used in isolation., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Objective:   To compare social and behavioural outcomes between children formally diagnosed with autism spectrum disorders (ASD) with those of children who displayed autistic traits at preschool age, but remained undiagnosed as teenagers., Method:   A secondary analysis of data from a birth cohort study, the Avon Longitudinal Study of Parents and Children (N = 13,944), in SW England. Children clinically diagnosed with ASD were identified from their medical records (n = 71). A comparison group, who displayed autistic traits at age 3-4, but without ASD diagnosis were also identified (n = 142). Social and behavioural outcomes in adolescence were compared between the two groups., Results:   Children with ASD diagnoses were more impaired as teenagers that those in the comparison group on a range of measures of autistic-like behaviour. The developmental trajectory of prosocial behaviour showed that differences between the case and comparison groups increased dramatically in the preschool and early primary years, but that after 6 years the trajectories were similar., Conclusions:   The divergence of the clinically diagnosed group and the nondiagnosed group in measures of autistic-like behaviour increased with age. This study provides evidence that it may be difficult to distinguish preschool age children who exhibit autistic-like symptoms but improve, from those who go on to develop lifelong impairment., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: The nosology of autism spectrum disorders (ASD) is at a critical point in history as the field seeks to better define dimensions of social-communication deficits and restricted/repetitive behaviors on an individual level for both clinical and neurobiological purposes. These different dimensions also suggest an increasing need for quantitative measures that accurately map their differences, independent of developmental factors such as age, language level and IQ., Method: Psychometric measures, clinical observation as well as genetic, neurobiological and physiological research from toddlers, children and adults with ASD are reviewed., Results: The question of how to conceptualize ASDs along dimensions versus categories is discussed within the nosology of autism and the proposed changes to the DSM-5 and ICD-11. Differences across development are incorporated into the new classification frameworks., Conclusions: It is crucial to balance the needs of clinical practice in ASD diagnostic systems, with neurobiologically based theories that address the associations between social-communication and restricted/repetitive dimensions in individuals. Clarifying terminology, improving description of the core features of ASD and other dimensions that interact with them and providing more valid and reliable ways to quantify them, both for research and clinical purposes, will move forward both practice and science., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Background: Purpose of this study was to systematically examine combined use of the Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) for children under age 4 using newly developed and revised diagnostic algorithms., Methods: Single and combined use of the ADI-R and ADOS algorithms were compared to clinical best estimate diagnoses for 435 children with autism spectrum disorders (ASD), 113 children with nonspectrum disorders, and 47 children with typical development from 12 to 47 months of age. Sequential strategies to reach a diagnostic decision by prioritizing administrations of instruments were also evaluated., Results: Well-balanced sensitivities and specificities above 80% were obtained for ASD diagnoses using both instruments. Specificities significantly improved when both instruments were used compared to one. Scores that can be used to systematically prioritize administrations of instruments were identified., Conclusions: The ADI-R and ADOS make independent, additive contributions to more accurate diagnostic decisions for clinicians evaluating toddlers and young preschoolers with ASD. Sequential assessment strategies using the scores identified may be appropriate for some children., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: To compare childhood arrestees with matched comparison groups on levels of autistic symptoms and to assess the unique predictive value of autistic symptoms for future delinquent behavior in childhood arrestees., Methods: Childhood first-time arrestees (n = 308, baseline age 10.7 ± 1.5 years) were followed up for 2 years. Autistic symptoms, externalizing disorders and delinquent behavior were assessed yearly. Childhood arrestees were compared on autistic symptoms with matched (age, gender) general population and clinical autism spectrum disorder samples. The predictive value of autistic symptoms for delinquent behavior was analyzed using generalized estimating equations., Results: At each assessment, levels of autistic symptoms in childhood arrestees were in between levels found in the general population and autism spectrum disorder samples. Autistic symptoms were positively associated with delinquent behavior in childhood arrestees, even after adjustment for externalizing disorders: IRR (incidence rate ratio) 1.23; 95% CI 1.11-1.36 and IRR 1.29; 95% CI 1.15-1.45 for core autistic symptoms and total symptom score, respectively., Conclusions: Autistic symptoms are more prevalent in childhood arrestees compared to the general population and are uniquely associated with future delinquent behavior. Attention should, therefore, be given to the possible presence of autism related symptomatology in these children. Implications for diagnostic assessment and intervention need further investigation., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: Maximizing measurement accuracy is an important aim in child development assessment and research. Parents are essential informants in the diagnostic process, and past research suggests that certain parental characteristics may influence how they report information about their children. This has not been studied in autism spectrum disorders (ASD) to date. We aimed, therefore, to investigate the possible effect that maternal depression might have on a mother's reports of her child's ASD behaviors. Using structural equation modeling, we disaggregated shared from unique variation in the association between latent variable measures of maternal depression and ASD behaviors., Methods: Data were obtained from a study of preschoolers aged 2-4 newly diagnosed with ASD (n = 214). Information from a parent questionnaire, a semi-structured parent interview, and a semi-structured observational assessment was used to develop a latent variable measure of child ASD behaviors. Mothers reported on their own depression symptoms. We first modeled the covariance between maternal depression and child ASD behavior. Then, to quantify unique variation, we added covariance terms between maternal depression and the residual variation associated with the individual measures of child ASD behaviors., Results: The model demonstrated excellent fit to the underlying data. Maternal self-report of depression symptoms exhibited a significant association with the unique variance of the questionnaire report but not with the latent variable measure of child ASD behavior. A gradient pattern of association was demonstrated between maternal depression and the unique variance of the ASD measures: most strongly for the maternal questionnaire report, more weakly for the maternal semi-structured interview, and to a trivial extent for the observational interview., Conclusions: Parental depression may influence reporting of ASD behaviors in preschoolers. Shared method effects may also contribute to bias. This finding highlights the importance of obtaining multimethod reports of child ASD symptoms., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: Delays in development are a fundamental feature in diagnosing autism spectrum disorders (ASD). Age of language acquisition, usually obtained through retrospective caregiver report, is currently used to distinguish between categories within ASD. Research has shown that caregivers often report children as having acquired developmental milestones earlier or later than they were actually achieved. The current study examines the extent to which this phenomenon, referred to as 'telescoping,' impacts retrospective reports provided by caregivers of children with ASD., Methods: Participants were 127 caregivers of children referred for possible ASD or non-spectrum developmental delay. Caregivers were interviewed when children were 2, 3, 5, and 9 years of age. Caregiver-reported ages of first concern, language and non-diagnostic developmental milestones and interviewer-estimated age of onset were compared over time using linear models., Results: Significant telescoping of language milestones resulted in more children meeting language delay criteria as they grew older, in spite of original reports that their language was not delayed. There was little evidence of consistent telescoping of caregiver-reported ages of first concern, daytime bladder control, and independent walking. With time, the interviewers' judged ages of symptom onset increased, but remained prior to age three., Conclusions: Telescoping of caregiver-reported ages of language acquisition has implications for both clinical diagnosis and genetic studies using these milestones to increase homogeneity of samples. Results support proposals to remove specific age-based criteria in the diagnosis of ASD. Telescoping should be considered when working with any clinical population in which retrospectively recalled events are used in diagnosis., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: This randomized controlled trial compared Hanen's 'More than Words' (HMTW), a parent-implemented intervention, to a 'business as usual' control group., Methods: Sixty-two children (51 boys and 11 girls; M age = 20 months; SD = 2.6) who met criteria for autism spectrum disorders (ASD) and their parents participated in the study. The HMTW intervention was provided over 3.5 months. There were three measurement periods: prior to randomization (Time 1) and at 5 and 9 months post enrollment (Times 2 and 3). Children's communication and parental responsivity were measured at each time point. Children's object interest, a putative moderator, was measured at Time 1., Results: There were no main effects of the HMTW intervention on either parental responsivity or children's communication. However, the effects on residualized gains in parental responsivity from Time 1 to both Times 2 and 3 yielded noteworthy effect sizes (Glass's Δ = .71, .50 respectively). In contrast, there were treatment effects on child communication gains to Time 3 that were moderated by children's Time 1 object interest. Children with lower levels of Time 1 object interest exhibited facilitated growth in communication; children with higher levels of object interest exhibited growth attenuation., Conclusions: The HMTW intervention showed differential effects on child communication depending on a baseline child factor. HMTW facilitated communication in children with lower levels of Time 1 object interest. Parents of children who evidence higher object interest may require greater support to implement the HMTW strategies, or may require different strategies than those provided by the HMTW curriculum., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: Research indicates that having child siblings is positively associated with theory of mind (ToM) in typically developing children. As ToM is important to everyday social behaviours it is important to extend this research to examine whether there are similar sibling effects for children with autism spectrum disorders (ASD)., Methods: Theory of mind and executive functioning abilities of 60 children clinically diagnosed with ASD were assessed with batteries of standard tasks. Verbal mental age (VMA) and severity of autism symptoms were also measured together with number of child-aged siblings (1 to 12 years) and position in the sibling constellation., Results: Having older siblings was a significant negative predictor of ToM performance for children with ASD, even after controlling for age, VMA, executive function and autism symptom severity. A weaker ToM benefit of younger siblings was not statistically significant independently of control variables., Conclusions: In sharp contrast to findings for typically developing preschoolers, having an older sibling was a disadvantage for ToM development in children with ASD. Conceivably, older siblings may over-compensate for their younger ASD siblings in social interactions, thereby limiting opportunities for social-cognitive growth. Parental attitudes, family resources, cultural norms and access to educational interventions may also conceivably be relevant and clearly warrant further research., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

The expression of autism spectrum disorder (ASD) is highly heterogeneous, owing to the complex interactions between genes, the brain, and behavior throughout development. Here we present a model of ASD that implicates an early and initial failure to develop the specialized functions of one or more of the set of neuroanatomical structures involved in social information processing (i.e., the 'social brain'). From this early and primary disruption, abnormal brain development is canalized because the individual with an ASD must develop in a highly social world without the specialized neural systems that would ordinarily allow him or her to partake in the fabric of social life, which is woven from the thread of opportunities for social reciprocity and the tools of social engagement. This brain canalization gives rise to other characteristic behavioral deficits in ASD including deficits in communication, restricted interests, and repetitive behaviors. We propose that focused efforts to explore the brain mechanisms underlying the core, pathognomic deficits in the development of mechanisms for social engagement in ASD will greatly elucidate our understanding and treatment of this complex, devastating family of neurodevelopmental disorders. In particular, developmental studies (i.e., longitudinal studies of young children with and without ASD, as well as infants at increased risk for being identified with ASD) of the neural circuitry supporting key aspects of social information processing are likely to provide important insights into the underlying components of the full-syndrome of ASD. These studies could also contribute to the identification of developmental brain endophenotypes to facilitate genetic studies. The potential for this kind of approach is illustrated via examples of functional neuroimaging research from our own laboratory implicating the posterior superior temporal sulcus (STS) as a key player in the set of neural structures giving rise to ASD., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: Social and communication impairments are core deficits and prognostic indicators of autism. We evaluated the impact of supplementing a comprehensive intervention with a curriculum targeting socially synchronous behavior on social outcomes of toddlers with autism spectrum disorders (ASD)., Methods: Fifty toddlers with ASD, ages 21 to 33 months, were randomized to one of two six-month interventions: Interpersonal Synchrony or Non-Interpersonal Synchrony. The interventions provided identical intensity (10 hours per week in classroom), student-to-teacher ratio, schedule, home-based parent training (1.5 hours per month), parent education (38 hours), and instructional strategies, except the Interpersonal Synchrony condition provided a supplementary curriculum targeting socially engaged imitation, joint attention, and affect sharing; measures of these were primary outcomes. Assessments were conducted pre-intervention, immediately post-intervention, and, to assess maintenance, at six-month follow-up. Random effects models were used to examine differences between groups over time. Secondary analyses examined gains in expressive language and nonverbal cognition, and time effects during the intervention and follow-up periods., Results: A significant treatment effect was found for socially engaged imitation (p = .02), with more than doubling (17% to 42%) of imitated acts paired with eye contact in the Interpersonal Synchrony group after the intervention. This skill was generalized to unfamiliar contexts and maintained through follow-up. Similar gains were observed for initiation of joint attention and shared positive affect, but between-group differences did not reach statistical significance. A significant time effect was found for all outcomes (p < .001); greatest change occurred during the intervention period, particularly in the Interpersonal Synchrony group., Conclusions: This is the first ASD randomized trial involving toddlers to identify an active ingredient for enhancing socially engaged imitation. Adding social engagement targets to intervention improves short-term outcome at no additional cost to the intervention. The social, language, and cognitive gains in our participants provide evidence for plasticity of these developmental systems in toddlers with ASD. http://www.clinicaltrials.gov/ct2/show/NCT00106210?term = landa&rank = 3., (© 2010 The Authors. Journal of Child Psychology and Psychiatry. © 2010 Association for Child and Adolescent Mental Health.)

Background: While research indicates elevated behavioural and emotional problems in children with autism spectrum disorders (ASD) and decreased well-being in their parents, studies do not typically separate out the contribution of ASD from that of associated intellectual disabilities (ID). We investigated child behavioural and emotional problems, and maternal mental health, among cases with and without ASD and ID in a large population-representative sample., Methods: Cross-sectional comparison of child behavioural and emotional problems and maternal mental health measures among 18,415 children (5 to 16 years old), of whom 47 had an ASD, 51 combined ASD with ID, 590 had only ID, and the remainder were the comparison group with no ASD or ID., Results: The prevalence of likely clinical levels of behavioural and emotional problems was highest among children with ASD (with and without ID). After controlling for age, gender, adversity, and maternal mental health, the presence of ASD and ID significantly and independently increased the odds for hyperactivity symptoms, conduct, and emotional problems. Emotional disorder was more prevalent in mothers of children with ASD (with or without ID). The presence of ASD, but not ID, significantly increased the odds for maternal emotional disorder. As has been found in previous research, positive maternal mental health was not affected by the presence of ASD or ID., Conclusions: ASD and ID are independent risk factors for behavioural and emotional problems. ASD (but not ID) is positively associated with maternal emotional disorder. Approaches to diagnosing hyperactivity and conduct problems in children with ASD may need to be reconsidered., (© 2010 The Authors. Journal of Child Psychology and Psychiatry. © 2010 Association for Child and Adolescent Mental Health.)

Background: Children with autism spectrum disorders (ASD) are increasingly included in general education classrooms in an effort to improve their social involvement., Methods: Seventy-nine children with ASD and 79 randomly selected, gender-matched peers (88.6% male) in 75 early (K-1), middle (2nd-3rd), and late (4th-5th) elementary classrooms across 30 schools completed social network surveys examining each child's reciprocal friendships, peer rejection, acceptance, and social involvement., Results: Across grade levels, peers less frequently reciprocated friendships with children with ASD than students in the matched sample. While children with ASD were not more likely to be rejected by peers, they were less accepted and had fewer reciprocal friendships than matched peers at each grade level. Although 48.1% of children with ASD were involved in the social networks of their classrooms, children with ASD were more likely to be isolated or peripheral to social relationships within the classroom across all grade levels, and this difference is even more dramatic in later elementary grades., Conclusions: In inclusive classrooms, children with ASD are only involved in peers' social relationships about half of the time, and appear to be even less connected with increasing grade level. Promoting children with ASD's skills in popular activities to share with peers in early childhood may be a key preventive intervention to protect social relationships in late elementary school grades., (© 2010 The Authors. Journal of Child Psychology and Psychiatry © 2010 Association for Child and Adolescent Mental Health.)

Background: The Parenting Stress Index-Short Form (PSI-SF) is one of the most widely used instruments for measuring parenting stress in families of children with autism spectrum disorders (ASD). However, no research to date has examined the psychometric properties of the PSI-SF in a sample of parents of young children with ASD. In this regard, item response theory (IRT) can be used to estimate how much information or discrimination each item of a scale offers across the entire range of the latent variable being measured, by creating individual item information curves or profiles. The purpose of this study was to use IRT to examine the discriminability of PSI-SF items in a sample of parents of young children with ASD who experience varying levels of parental stress., Methods: The study involved the parents of 141 children with autism spectrum disorders (91.4% mothers; mean age 36.2 years) who completed the PSI-SF following diagnosis. Item characteristic curves were constructed for each of the PSI-SF items and examined with regard to item functioning., Results: Results indicated that, for the most part, changes in parental distress severity were reflected in changes on item scores. However, several items on the subscales measuring parent-child dysfunctional interactions and child behavior difficulty functioned poorly to discriminate parents across a range of total stress severity., Conclusions: The parent-child dysfunctional interaction and difficult child subscales of the PSI-SF scale should be used with caution with parents of young children with ASD. More research is required to examine PSI-SF content validity, at least among parents of children with ASD and perhaps parents of children with other disabilities as well., (© 2010 The Authors. Journal of Child Psychology and Psychiatry © 2010 Association for Child and Adolescent Mental Health.)

Background: The Social Communication Questionnaire (SCQ) is a screening instrument with established validity against the Autism Diagnostic Interview-Revised (ADI-R) in children aged 4 years and older. Indices of diagnostic accuracy have been shown to be strong in school-aged samples; however, relatively little is known about the performance of the SCQ in toddlers at risk of autism spectrum disorder (ASD)., Methods: This study replicates and extends previous research by Corsello et al. (2007) in a comparatively large (N = 208), substantially younger (20-40 months) sample of children at high risk of ASD. The usefulness of the SCQ as a second-level screening instrument with different cut-off scores was evaluated in relation to IQ, age, and type of ASD diagnosis. The use of the SCQ as compared to the ADI-R was evaluated against clinical diagnosis, both alone and in combination with the ADOS., Results: The SCQ with different cut-offs consistently showed an unsatisfactory balance between sensitivity and specificity in screening for ASD in high-risk toddlers, with only a few exceptions for specific age, IQ, or diagnostic groups. Even though the SCQ and ADI-R were highly correlated, diagnostic agreement with the best evidence clinical diagnosis was poor for both measures. The ADOS used alone consistently had the highest predictive value. For autism versus not-autism, the combined SCQ and ADOS performed as well as the ADOS alone and notably better than the combination ADI-R and ADOS., Conclusions: The SCQ is likely to result in a number of false-positive findings, particularly in children with autism symptomatology, and the balance between sensitivity and specificity is poor. The ADOS should be considered the most valid and reliable diagnostic instrument in these very young at-risk children., (© 2010 The Authors. Journal of Child Psychology and Psychiatry © 2010 Association for Child and Adolescent Mental Health.)

Background: The 'broken mirror' theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence., Methods: In this electroencephalographic study, we examined mu suppression, as an indicator of sensorimotor resonance, concurrent with oculomotor performance while individuals (n = 20) with ASD and control participants (n = 20) either executed hand actions or observed hand actions or a moving dot. No difference in visual attention between groups was found as indicated by fixation duration and normalized fixation number on the presented stimuli., Results: The mu suppression over the sensorimotor cortex was significantly affected by experimental conditions, but not by group membership, nor by the interaction between groups and conditions. Individuals with ASD, similar to the controls, exhibited stronger mu suppression when watching hand actions relative to a moving dot. Notably, participants with ASD failed to imitate the observed actions while their mu suppression indicating the MNS activity was intact. In addition, the mu suppression during the observation of hand actions was positively associated with the communication competence of individuals with ASD., Conclusion: Our study clearly challenges the broken mirror theory of autism. The functioning of the mirror neuron system might be preserved in individuals with ASD to a certain degree. Less mu suppression to action observation coupled with more communicational severity can reflect the symptom heterogeneity of ASD. Additional research needs to be done, and more caution should be used when reaching out to the media.

Background: Difficulties in communication and reciprocal social behavior are core features of autism spectrum disorders (ASD) and are often present, to varying degrees, in other family members. This prospective longitudinal infant sibling study examines whether social-communicative features of family members may inform which infants are at increased risk for ASD and other developmental concerns., Method: Two hundred and seventeen families participated in this study. Infant siblings were recruited from families with at least one older child diagnosed with an ASD (n = 135) or at least one typically developing older child (n = 82). Families completed the Social Responsiveness Scale to assess social and communication features of the broader autism phenotype (BAP), sometimes called quantitative autistic traits (QAT). Family affectedness was assessed in two ways: categorically, based on number of affected older siblings (i.e., typical, simplex, multiplex risk groups) and dimensionally, by assessing varying degrees of QAT in all family members. Infant siblings were assessed at 36 months of age and completed the Autism Diagnostic Observation Schedule and the Mullen Scales of Early Learning., Results: In structural equation models, comparisons between multiplex, simplex and typical groups revealed the highest rates of QAT in the multiplex group followed by the simplex and typical groups. Infant sibling outcomes were predicted by gender, family risk group, proband QAT, and additional sibling QAT., Conclusions: Replicating previous cross-sectional and family history findings, the present study found elevated social and communication features of the BAP in siblings and fathers of ASD families, but not in mothers. While social and communication features of the BAP in mothers, fathers, and undiagnosed siblings did not predict infant sibling outcomes, having more than one affected older sibling did. Infant siblings from multiplex families were at significantly higher risk for ASD than infant siblings from simplex families in this sample.

Background: Data from epidemiology have consistently highlighted a disparity between the true prevalence of childhood psychiatric disorders and their recognition as defined by receiving a clinical diagnosis. Few studies have looked specifically at the level of unidentified autistic spectrum disorder (ASD) in the population., Method: Logistic regression was used to determine the behavioural traits associated with receiving a diagnosis of ASD using data from the Avon Longitudinal Study of Parents and Children (ALSPAC). A composite score was derived to measure levels of autistic traits; undiagnosed children with scores matching those diagnosed with ASD were identified. Levels of educational provision beyond that provided by standard schooling were examined., Results: Fifty-five percent of children with autistic traits at the same levels as those who had an autism diagnosis had not been identified as needing extra support from education or specialised health services. Of those who were identified as having special needs, 37.5% had been formally diagnosed with an ASD. For children with impairment at the same level as that associated with Asperger's syndrome, 57% had no special provision at school, and were not accessing specialised health services. Twenty-six percent of those who did have special provision at school had an ASD diagnosis., Conclusions: The results suggest that there may be a substantial proportion of children on the autistic spectrum who are never identified by services.

Background: Few field trials exist on the impact of implementing guidelines for the early detection of autism spectrum disorders (ASD). The aims of the present study were to develop and evaluate a clinically relevant integrated early detection programme based on the two-stage screening approach of Filipek et al. (1999), and to expand the evidence base for this approach., Methods: The integrated early detection programme encompassed: 1) training relevant professionals to recognise early signs of autism and to use the Early Screening of Autistic Traits Questionnaire (ESAT; Dietz, Swinkels et al., 2006; Swinkels, van Daalen, van Engeland, & Buitelaar, 2006), 2) using a specific referral protocol, and 3) building a multidisciplinary diagnostic team. The programme was evaluated in a controlled study involving children in two regions (N = 2793, range 0-11 years). The main outcome variables were a difference in mean age at ASD diagnosis and a difference in the proportion of children diagnosed before 36 months., Results: ASD was diagnosed 21 months (95% CI 9.6, 32.4) earlier in the experimental region than in the control region during the follow-up period, with the mean age at ASD diagnosis decreasing by 19.5 months (95% CI 10.5, 28.5) from baseline in the experimental region. Children from the experimental region were 9.4 times (95% CI 2.1, 41.3) more likely than children from the control region to be diagnosed before age 36 months after correction for baseline measurements. Most of these early diagnosed children had narrowly defined autism with mental retardation., Conclusions: The integrated early detection programme appears to be clinically relevant and led to the earlier detection of ASD, mainly in children with a low IQ.

Background: Despite recent increases in the number of toddlers referred for a differential diagnosis of autism spectrum disorders (ASD), knowledge of short-term stability of the early diagnosis as well as cognitive outcomes in this cohort is still limited., Method: Cognitive, social, and communication skills of 89 clinic-referred toddlers were assessed at the average age of 21.5 (SD = 4.9) months, and reassessed at 46.9 (SD = 7.7) months. Groups with stable and unstable diagnostic presentation were identified and compared on their profile of cognitive and social-communicative skills obtained at the time of initial diagnosis., Results: Stability of the ASD diagnosis was 100%; diagnosis of autism was stable in 74% of cases as compared to 83% and 81% in PDD-NOS and Non-ASD groups, respectively. Worsening of social disability symptoms resulting in autism diagnosis was noted in 17% of toddlers initially diagnosed with PDD-NOS and in 19% of toddlers with initial diagnosis of non-ASD disorder. However, marked improvement was noted in approximately 1/4 of children initially presenting with autism, warranting diagnostic reassignment to PDD-NOS at follow-up. An analysis of developmental skills profiles suggests particular relevance of the assessment of verbal and nonverbal communication skills to diagnostic differentiation between subtypes within ASD in the second year of life., Conclusions: Stability of ASD diagnosis in toddlers is high, though marked changes in severity of symptoms is to be expected in a minority of cases. Simultaneous consideration of cognitive, social, and communication skills profiles enhances accuracy of diagnostic classification and prediction of outcome.

Background: Empirical studies of the structure of autism symptoms have challenged the three-domain model of impairment currently characterizing pervasive developmental disorders (PDD). The objective of this study was to assess the internal validity of the DSM as a conceptual model for describing PDD, while paying particular attention to certain subject characteristics., Methods: Parents and teachers completed a DSM-IV-referenced rating scale for 3- to 12-year-old clinic referrals with a PDD (n = 730). Ratings were submitted to confirmatory factor analysis and different models were assessed for fit., Results: Measures of fit indicated that the three-factor solution based on the DSM was superior to other models. Most indices of fit were acceptable, but showed room for improvement. Fit indices varied according to the rater (parent or teacher), child's age (preschool versus school aged), PDD subtype (autism, Asperger's, pervasive developmental disorder not otherwise specified (PDDNOS)), and IQ., Conclusions: More research needs to be done before discarding current classification systems. Subject characteristics, modality of assessment, and procedural variations in statistical analyses impact conclusions about the structure of PDD symptoms.

Background: Despite extensive research, it is still debated whether impairments in social skills of individuals with pervasive developmental disorder (PDD) are related to specific deficits in the early processing of emotional information. We aimed to test both automatic processing of facial affect as well as the integration of auditory and visual emotion cues in individuals with PDD., Methods: In a group of high-functioning adult individuals with PDD and an age- and IQ-matched control group, we measured facial electromyography (EMG) following presentation of visual emotion stimuli (facial expressions) as well as the presentation of audiovisual emotion pairs (faces plus voices). This emotionally driven EMG activity is considered to be a direct correlate of automatic affect processing that is not under intentional control., Results: Our data clearly indicate that among individuals with PDD facial EMG activity is heightened in response to happy and fearful faces, and intact in response to audiovisual affective information., Conclusions: This study provides evidence for enhanced sensitivity to facial cues at the level of reflex-like emotional responses in individuals with PDD. Furthermore, the findings argue against impairments in crossmodal affect processing at this level of perception. However, given how little comparative work has been done in the area of multisensory perception, there is certainly need for further exploration.

Background: Exposure to harsh parenting and children's skills in 'Theory of Mind' (ToM) show independent and interacting associations with problem behaviors at age 2 (Hughes & Ensor, 2006). This study examined whether these age-2 measures also predict age-4 problem behaviors., Method: In a socially diverse sample (N = 120), multi-informant, multi-measure, multi-setting ratings indexed problem behaviors at ages 2, 3 and 4; children completed both ToM and verbal-ability tasks at age 2, while video-based ratings of maternal negative affect and control within dyadic mother-child play indexed harsh parenting., Results: Age-2 harsh parenting and ToM were independent and interacting predictors of age-4 problem behaviors, even with age-2 problem behaviors, verbal ability and social disadvantage all controlled. The interaction between harsh parenting and ToM distinguished persistent vs. diminishing problem behaviors., Conclusions: Both child and family characteristics predict increases in problem behaviors from 2 to 4; adverse effects of harsh parenting are attenuated for children with good ToM skills.

Background: Relatively little is known about the genetic architecture of childhood behavioral disorders in very young children., Method: In this study, parents completed the Infant-Toddler Social and Emotional Assessment, a questionnaire that assesses symptoms of childhood disorders, as well as socio-emotional competencies, for 822 twin pairs (49.3% female; age 17-48 months) participating in the Wisconsin Twin Project. Psychometric, rater bias, and sex-limitation models explored the role of genetic and environmental influences on (1) externalizing and internalizing behavior; (2) less commonly assessed behaviors pertaining to physical and emotional dysregulation, general competencies, social relatedness; and (3) infrequent behaviors such as those associated with pervasive developmental delays., Results: Heritable influences accounted for the majority (56% or more) of variation in behavior that was commonly observed by both parents. The remaining variance was associated with non-shared environmental factors, with the exception of competency and atypical behavior, which were also influenced by shared environmental factors. In contrast, for most behaviors, the variation unique to mother and father ratings was split between variation due to shared environment or rater biases and to measurement error. Little evidence emerged for sex differences in the underlying causes of variation.

Background: Few studies have examined the variability in outcomes of children diagnosed with autism spectrum disorder (ASD) at age 2. Research is needed to understand the children whose symptoms - or diagnoses - change over time. The objectives of this study were to examine the behavioral and diagnostic outcomes of a carefully defined sample of 2-year-old children with ASD, and to identify child and environmental factors that contribute to variability in outcomes at age 4., Methods: Forty-eight children diagnosed with autism or pervasive developmental disorder not otherwise specified (PDDNOS) at age 2 were followed to age 4. Diagnostic measures included the Autism Diagnostic Observation Schedule - Generic (ADOS-G) and clinical diagnosis at ages 2 and 4, and the ADI-R at age 4., Results: Diagnostic stability for an ASD diagnosis (autism or PDDNOS) was 63%, and for an autism diagnosis was 68%. Children who failed to meet diagnostic criteria for ASD at follow-up were more likely to: 1) be 30 months or younger at initial evaluation; 2) have milder symptoms of autism, particularly in the social domain; and 3) have higher cognitive scores at age 2. No differences between children with stable and unstable diagnoses were found for amount of intervention services received. Among the children with unstable diagnoses, all but one continued to have developmental disorders, most commonly in the area of language., Conclusions: The stability of ASD was lower in the present study than has been reported previously, a finding largely attributable to children who were diagnosed at 30 months or younger. Implications for clinical practice are discussed.

Background: Repetitive and stereotyped behaviours are a heterogeneous group of behaviours present in many neuropsychiatric disorders. Despite their core significance in PDD, it is not clear whether there are distinct groups of these behaviours with different specificity to autism., Methods: A two-factor model of the repetitive behaviours, namely sensory/motor (lower-order) and cognitive rigidity (higher-order), was conceptualised. The model's goodness of fit to the data was examined in a clinic population of children with PDD, with and without mental retardation, and of those with only mental retardation (MR)., Results: Subjects with PDD had higher rates of all repetitive behaviours compared to those with MR only. The existence of two independent 'lower-order' and 'higher-order' sub-groups of the repetitive behaviours was confirmed only in the MR group. The lower-order behaviours appear to be associated more with global developmental problems, whereas the higher-order behaviours were significantly associated with ruminations in the PDD group., Conclusions: This study suggests that there may be two distinct sub-groups of repetitive behaviours whereby the sensory and motor repetitive behaviours are generally associated with lower developmental age and less specific to the autistic syndrome whereas the 'higher-order' behaviours may be a more 'autism specific' feature. The co-occurrence of the lower- and higher-order behaviours in PDD might reflect the end result of diffuse altered neural networks in these disorders thus being a specific feature of PDD. There is a need for more systematic studies of these behaviours not only in autistic disorders but also in other neuropsychiatric disorders.

Background: Unusual responses to sensory stimuli are seen in many children with autism. Their presence was highlighted both in early accounts of autism and in more recent first-person descriptions. There is a widespread belief that sensory symptoms characterize autism and differentiate it from other disorders. This paper examines the empirical evidence for this assumption., Method: All controlled experimental laboratory investigations published since 1960 were identified through systematic searches using Medline/PubMed and PsycInfo search engines. A total of 48 empirical papers and 27 theoretical or conceptual papers were reviewed., Results: Sensory symptoms are more frequent and prominent in children with autism than in typically developing children, but there is not good evidence that these symptoms differentiate autism from other developmental disorders. Certain groups, including children with fragile X syndrome and those who are deaf-blind, appear to demonstrate higher rates of sensory symptoms than children with autism. In reviewing the evidence relevant to two theories of sensory dysfunction in autism, over- and under-arousal theory, we find that there is very little support for hyper-arousal and failure of habituation in autism. There is more evidence that children with autism, as a group, are hypo-responsive to sensory stimuli, but there are also multiple failures to replicate findings and studies that demonstrate lack of group differences., Conclusions: The use of different methods, the study of different sensory modalities, and the changing scientific standards across decades complicate interpretation of this body of work. We close with suggestions for future research in this area.

Background: Insight into the prevalence of pervasive developmental disorder (PDD) in children and adolescents with mental retardation (MR) is known to be of clinical importance. However, estimating this prevalence is complicated. The literature reports prevalence rates ranging from 3% through 50%. This variation seems to be related to the concepts of PDD under study, the instruments used, and the studied populations. The present study aimed to estimate a reliable prevalence rate of PDD., Methods: A total population-based screening with the PDD-MRS and the ABC (n=825) was followed by further assessment of children and adolescents at high risk for PDD according to these instruments, and for controls, with the ADI-R, ADOS-G and a DSM-IV-TR classification (n=188)., Results: The instruments lead to different prevalence rates that range from 7.8% to 19.8%. The differences in the estimated prevalence rates are related to the concept of PDD and the instruments they represent. The DSM-IV-TR prevalence (16.7%) seems to be the most reliable and well-founded estimate, since this prevalence rate is based on information from multiple informants and multiple time periods., Conclusions: The reported prevalence rates provide policy makers with an up-to-date and more substantiated guideline for the allocation of resources for children and adolescents with MR and PDD. The height of the prevalence should alert professionals that PDD is widespread in the population with MR.