Epidemiology of Pervasive Developmental Disorders

Department of Psychiatry, Montreal Children's Hospital of the McGill University Health Centre, Montreal, Quebec, Canada.
Pediatric Research (Impact Factor: 2.31). 03/2009; 65(6):591-8. DOI: 10.1203/PDR.0b013e31819e7203
Source: PubMed


This article reviews the results of 43 studies published since 1966 that provided estimates for the prevalence of pervasive developmental disorders (PDDs), including autistic disorder, Asperger disorder, PDD not otherwise specified, and childhood disintegrative disorder. The prevalence of autistic disorder has increased in recent surveys and current estimates of prevalence are around 20/10,000, whereas the prevalence for PDD not otherwise specified is around 30/10,000 in recent surveys. Prevalence of Asperger disorder is much lower than that for autistic disorder and childhood disintegrative disorder is a very rare disorder with a prevalence of about 2/100,000. Combined all together, recent studies that have examined the whole spectrum of PDDs have consistently provided estimates in the 60-70/10,000 range, making PDD one of the most frequent childhood neurodevelopmental disorders. The meaning of the increase in prevalence in recent decades is reviewed. There is evidence that the broadening of the concept, the expansion of diagnostic criteria, the development of services, and improved awareness of the condition have played a major role in explaining this increase, although it cannot be ruled out that other factors might have also contributed to that trend.

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Available from: Eric Fombonne, Apr 01, 2015
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    • "The relevance of accurate diagnosis of autism has become greater than ever, particularly in view of the increasing prevalence [26], elevated costs for both family and society [27], and accepted importance of early identification and intervention in individuals with autism. The classification systems used strongly affect prevalence studies, and it is important to consider the changes that have occurred at this level when analyzing the possible causes of the increase in pervasive developmental disorders [28]. "
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    ABSTRACT: Symptoms of inattention and hyperactivity, features of attention-deficit/hyperactivity disorder (ADHD), have been frequently documented in children with autism spec‐ trum disorders (ASDs) and often co-occur. Evidence indicates that 20-50% of children with ADHD meet criteria for ASD, and 30-80% of ASD children meet criteria for ADHD. According to the DSM-IV, the essential features of Autistic Disorder (AD) are " the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interests ". Differ‐ ential diagnosis of " Pervasive Developmental Disorder " (PDD: Autistic Disorder, Re‐ tt's Disorder, Childhood Disintegrative Disorder, Asperger's Disorder) and " Pervasive Developmental Disorder-Not Otherwise Specified " (PDD-NOS) is often difficult in the preschool child. This is particularly true when assessing verbal and nonverbal com‐ munication since both expressive and cognitive language are not yet established and there are many differences in their acquisition period among these children (before the age of three). As a result, many of these children are diagnosed with PDD-NOS not meeting the criteria for a specific type of PDD; this category includes "atypical au‐ tism" presentations that do not meet the criteria for AD. As a result, the concept of PDD-NOS has become a mixed bag. Often, diagnosis cannot be established before age three, delaying therapeutic interventions. Moreover, differential diagnosis between ADHD and PDD-NOS can be especially difficult, mainly in infant and young chil‐ dren. However, and following the recommendations of the DSM-IV, the ASDs diag‐ nosis has been included among the exclusion criteria for the ADHD. Such exclusion has generated considerable controversy regarding the necessity and benefits of main‐ taining these separations. At present, a new edition of the DSM has been published: DSM-5® (Fifth Edition, 2013). Among the advantages that this new manual provides are: i) further categoriza‐ tion of the persons affected and ii) the possibility of diagnosis before the age of three. The DSM-5 takes into account that limitations in language are not specific to autism. The new diagnostic category " Social Communication Disorder " appears separate from ASD, which does not seek to create a new subcategory. In light of the new DSM-V criteria which allow a dual diagnosis of ASD and ADHD behaviors, in this chapter we will review the clinical overlap of these two conditions, particularly regarding their comorbidities in community pre-schoolers (generally categorized as PDD-NOS). We will also look into possible future research directions necessary to enhance our understanding of the etiology/genetics factors as well as the appropriate sequence of therapeutic interventions and pharmacological treatment (psychostimulant and nonstimulant medications) for the co-occurrence of these disor‐ ders.
    ADHD - New Directions in Diagnosis and Treatment, Edited by Dr. Jill M. Norvilitis, 09/2015: chapter Chapter 6: pages 109-164; InTech- Open Access Publisher., ISBN: 978-953-51-2166-4
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    • "Le TSA est associé à une incidence plus élevée pour certains problèmes de santé. Des études estiment que 40 % de ces personnes auraient une déficience intellectuelle associée (Baird, et al. 2006 ; Fombonne, 2009) et que 70 % présenteraient une comorbidité (Simonoff et al., 2008). Près de 30 % de ces individus souffriraient aussi d'épilepsie (Tuchman, Cuccaro, & Alessandri, 2010). "
    Sante mentale au Quebec 09/2015; 40(1):203-226.
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    • "From 2013, all children with autism, Asperger's syndrome, or other pervasive developmental disorders will receive one umbrella diagnosis of autism spectrum disorder (ASD) [2]. There has been a steady increase in the prevalence of ASD over the last twenty years [3] [4]. This may however be due to increased access to diagnostic services or increasing awareness of the condition. "
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    ABSTRACT: In recent years, it has become clear that children with autism spectrum disorders (ASDs) have difficulty with gross motor function and coordination, factors which influence gait. Knowledge of gait abnormalities may be useful for assessment and treatment planning. This paper reviews the literature assessing gait deviations in children with ASD. Five online databases were searched using keywords “gait” and “autism,” and 11 studies were found which examined gait in childhood ASD. Children with ASD tend to augment their walking stability with a reduced stride length, increased step width and therefore wider base of support, and increased time in the stance phase. Children with ASD have reduced range of motion at the ankle and knee during gait, with increased hip flexion. Decreased peak hip flexor and ankle plantar flexor moments in children with ASD may imply weakness around these joints, which is further exhibited by a reduction in ground reaction forces at toe-off in children with ASD. Children with ASD have altered gait patterns to healthy controls, widened base of support, and reduced range of motion. Several studies refer to cerebellar and basal ganglia involvement as the patterns described suggest alterations in those areas of the brain. Further research should compare children with ASD to other clinical groups to improve assessment and treatment planning.
    04/2015; 2015:1-8. DOI:10.1155/2015/741480
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