The Autism Epidemic: Fact or Artifact?

doi:10.1097/chi.0b013e31804a7f3b

Journal of the American Academy of Child & Adolescent Psychiatry

Volume 46, Issue 6, June 2007, Pages 721-730

https://doi.org/10.1097/chi.0b013e31804a7f3b Get rights and content

ABSTRACT

Objective

We provide an illustration of how changes in methodological factors may produce variations in the frequency of autistic disorder (AD) over time and project how much of the observed increase in the frequency of AD may be explained by methodological factors.

Method

Using a prediction analysis, we calculate how broadening diagnostic criteria, younger age at diagnosis, and improved efficiency of case ascertainment could produce temporal trends in the incidence and prevalence of AD, measured by calendar year and by year of birth, in a hypothetical population of children 0 to 18 across the years 1950 to 2020.

Results

Time trend studies report an increase as large as 11.0-fold over a 13-year period for AD. Conservative changes in the three methodological factors produced increases in the frequency of AD ranging from 2.1- to 28.8-fold. Measures of frequency by year of birth show the largest magnitude of increase; predicted prevalence by calendar year and to age 4 by year of birth are influenced by changes in the distribution of age at diagnosis, but 1-year incidence and prevalence to age 12 are not.

Discussion

Methodological factors may explain the observed increases in AD over time. To increase confidence in reports of time trends, we recommend particular frequency measures and study circumstances.

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The possibility that the rate of autism is increasing has fueled debate over the past decade (Fombonne, 2002, Fombonne, 2003b, Fombonne et al., 2001, Gillberg and Wing, 1999, Rutter, 2005, Williams et al., 2006, Wing and Potter, 2002). Recent epidemiological studies yield higher estimates than earlier

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Between 2009 and 2017, approximately 1 in 6 children between the ages of 3 and 17 in the United States had a developmental disorder, the primary disorders being attention-deficit/hyperactivity disorder (9.04%), learning disability (7.74%), stuttering/stammering (2.02%) and autism spectrum disorder (ASD, 1.74%) (Zablotsky et al., 2019). For ASD, the prevalence has increased from 1 in 150 children in the year 2000 to the current approximation of 1 in 54 children (Maenner et al., 2020), due in part to a broadened definition and a growing awareness of ASD (Wazana et al., 2007). The core symptoms of ASD are restricted and repetitive behaviors and impairments in communication skills and social interactions (American Psychiatric Association, 2013).
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Cette étude transversale recherche le taux de prévalence des troubles du spectre autistique (TSA) chez 818 enfants (16–48 mois) dans toutes les régions du Liban. Le dépistage a été effectué à l’aide du M-CHAT. Sur la base du score total, les enfants ont été classés en 3 catégories de risque de TSA (faible, modéré et élevé). Des entretiens de suivi des appels téléphoniques et des évaluations cliniques pour le diagnostic ont été menés. Compte tenu de la réticence des personnes à participer, le taux de prévalence était estimé entre 49 et 513 pour 10 000 avec une prédominance masculine. Notre estimation de la prévalence, même sous des hypothèses restrictives, est plus élevée qu’ailleurs dans la région arabe. Des interventions anti-stigmatisation adaptées au contexte socioculturel sont nécessaires avant de futures recherches dans le domaine.
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Autism spectrum disorder (ASD) is a genetically complicated neuropsychiatric developmental disorder. As the pathogenesis of ASD is not clear till now, we have carried out the present case-control study to validate the association of GRIK1 rs363598 and intergenic rs360932 polymorphisms with ASD in the Bangladeshi children.
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The estimated prevalence of ASD is 1.5% in children in the USA (CDC, 2016) and even higher for adolescents and young adults in Stockholm County, Sweden (Idring et al., 2015). ASD has been increasingly diagnosed during the past few decades, although the reasons for this increase are not fully understood (Christensen et al., 2016; Idring et al., 2015; Wazana, Bresnahan, & Kline, 2007). In most cases, ASD persists into adulthood (Helles, Gillberg, Gillberg, & Billstedt, 2015) and the consequences of having ASD are profound, also in intellectually able individuals (de Schipper et al., 2016; Howlin, Goode, Hutton, & Rutter, 2004; Jonsson et al., 2017; Magiati, Tay, & Howlin, 2014).
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Twenty-three out of the 29 included participants (79%) completed the intervention. The participants’ experience of treatment credibility was increased during the SCOPE web course and the overall satisfaction with the treatment was high. The coaches reported high treatment credibility and good clinical feasibility of the internet-based delivered intervention. The participants’ knowledge of ASD increased significantly from pre-intervention to post-intervention. The increased knowledge of ASD was not associated with negative effects on psychological well-being.
Our results suggest that the internet-delivered psychoeducational intervention SCOPE is a feasible intervention and could contribute to youth’s sense of empowerment through increased knowledge of ASD and themselves. An ongoing randomized controlled study will generate further evidence concerning the SCOPE intervention.
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The authors thank Dr. Ezra Susser who advised in the development of the models and Dr. Bruce Levin for his guidance in the statistical modeling of distribution of age at diagnosis.

Article Plus (online only) materials for this article appear on the Journal's Web site: www.jaacap.com.

Disclosure: The authors have no financial relationships to disclose.

View full text

ARTICLESThe Autism Epidemic: Fact or Artifact?

ABSTRACT

Objective

Method

Results

Discussion

Section snippets

ArticlePlus

J Am Acad Child Adolesc Psychiatry

J Am Acad Child Adolesc Psychiatry

J Am Acad Child Adolesc Psychiatry

Appl Res Ment Retard

Lancet

Int J Dev Neurosci

Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III)

Diagnostic and Statistical Manual of Mental Disorders, 3rd edition-revised (DSM-III-R)

Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV)

Relationship between age of recognition of first disturbances and severity in young children with autism

Eur Child Adolesc Psychiatry

A comparison study of autism spectrum disorder referrals 1997 and 1989

J Autism Dev Disord

The incidence of autism in Olmsted County, Minnesota, 1976–1997: results from a population-based study

Arch Pediatr Adolesc Med

How commonly are known medical conditions associated with autism?

J Autism Dev Disord

The role of mercury in the pathogenesis of autism

Mol Psychiatry

Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation

Pediatrics

Exploring the boundaries of pervasive developmental disorder not otherwise specified: analyses of data from the DSM-IV Autistic Disorder Field Trial

J Autism Dev Disord

Parental report if diagnosed autism in children aged 4–17 years-United States, 2003–2004

MMWR Morbid Mortal Wkly Rep

Pervasive developmental disorders in preschool children

JAMA

Autistic symptoms in children with attention deficit-hyperactivity disorder

Eur Child Adolesc Psychiatry

The prevalence of autistic spectrum disorder in children surveyed in a tertiary care epilepsy clinic

Epilepsia

Response: a response to Blaxill, Baskin and Spitzer on Croen etal. (2002), “The Changing Prevalence of Autism in California.”

J Autism Dev Disord

The changing prevalence of autism in California

J Autism Dev Disord

Time trends in autism and in MMR immunization coverage in California

JAMA

Epidemiological trends in rates of autism

Mol Psychiatry

Epidemiological surveys of autism and other pervasive developmental disorders: an update

J Autism Dev Disord

The prevalence of autism

JAMA

Prevalence of infantile autism in four French regions

Soc Psychiatry Psychiatr Epidemiol

Is autism more common now than ten years ago?

Br J Psychiatry

Autism: not an extremely rare disorder

Acta Psychiatr Scand

Prevalence of autism in Missouri: changing trends and the effect of a comprehensive state autism project

Mol Med

The recognition of autism in children with Down syndrome-implications for intervention and some speculations about pathology

Dev Med Child Neurol

ARTICLES
The Autism Epidemic: Fact or Artifact?