The first autism surveys were simple head counts of children already diagnosed with a severe autism phenotype and residing in small, circumscribed geographical areas. Prevalence was low, ranging from ...0.4 to 2/1,000 in the 1960's and 1970's. Today, the methodology of surveys has become more complex; studies include large populations, multiple sites, stratified samples and rely on intricate sets of screening activities followed by some form of diagnostic confirmation procedures. Yet, and as surprising as it may be, there is no standardization of autism survey methodology. Each survey has unique design features that reflect the local educational and health services infrastructure and current social policies for children with disabilities, they include or not parents, teachers and subjects with Autism Spectrum Disorder (ASD), and rely on variable screening and diagnostic instruments and methods. As such, prevalence differences between studies are hazardous to evaluate and whether observed discrepancies are due to method factors or true differences in population parameters, cannot be determined.
Camouflage and autism Fombonne, Eric
Journal of child psychology and psychiatry,
July 2020, 2020-07-00, 20200701, Letnik:
61, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The theme of camouflage recently gained unexpected momentum in autism research. Symposia and panel discussions are devoted to ‘ camouflage’ in autism conferences. Because of its association with ...intended deception, the term camouflage has poor fit with the autism world. However, psychopathologists have a long tradition of resorting to camouflage‐like terminology, from Freud’s reaction formation, to pseudoschizophrenia, to Winnicott’s false self, to masked depression, and even to the recent quasi‐autism, artfully telling us that what we see is actually not what we see but rather what we cannot see. Is ‘Camouflaged Autism’ the next in line nosographical pearl?
Prevalence estimates of autism are essential for informing public policy, raising awareness, and developing research priorities. Using a systematic review, we synthesized estimates of the prevalence ...of autism worldwide. We examined factors accounting for variability in estimates and critically reviewed evidence relevant for hypotheses about biological or social determinants (viz., biological sex, sociodemographic status, ethnicity/race, and nativity) potentially modifying prevalence estimates of autism. We performed the search in November 2021 within Medline for studies estimating autism prevalence, published since our last systematic review in 2012. Data were extracted by two independent researchers. Since 2012, 99 estimates from 71 studies were published indicating a global autism prevalence that ranges within and across regions, with a median prevalence of 100/10,000 (range: 1.09/10,000 to 436.0/10,000). The median male‐to‐female ratio was 4.2. The median percentage of autism cases with co‐occurring intellectual disability was 33.0%. Estimates varied, likely reflecting complex and dynamic interactions between patterns of community awareness, service capacity, help seeking, and sociodemographic factors. A limitation of this review is that synthesizing methodological features precludes a quality appraisal of studies. Our findings reveal an increase in measured autism prevalence globally, reflecting the combined effects of multiple factors including the increase in community awareness and public health response globally, progress in case identification and definition, and an increase in community capacity. Hypotheses linking factors that increase the likelihood of developing autism with variations in prevalence will require research with large, representative samples and comparable autism diagnostic criteria and case‐finding methods in diverse world regions over time.
Lay Summary
We reviewed studies of the prevalence of autism worldwide, considering the impact of geographic, ethnic, and socioeconomic factors on prevalence estimates. Approximately 1/100 children are diagnosed with autism spectrum disorder around the world. Prevalence estimates increased over time and varied greatly within and across sociodemographic groups. These findings reflect changes in the definition of autism and differences in the methodology and contexts of prevalence studies.
There is some uncertainty about the rate and correlates of autism.
Twenty-three epidemiological surveys of autism published in the English language between 1966 and 1998 were reviewed.
Over 4 million ...subjects were surveyed; 1533 subjects with autism were identified. The methodological characteristics of each study are summarized, including case definition, case-finding procedures, participation rates and precision achieved. Across surveys, the median prevalence estimate was 5.2/10000. Half the surveys had 95% confidence intervals consistent with population estimates of 5.4-5.5/10000. Prevalence rates significantly increased with publication year, reflecting changes in case definition and improved recognition; the median rate was 7.2/10 000 for 11 surveys conducted since 1989. The average male/female ratio was 3.8:1, varying according to the absence or presence of mental retardation. Intellectual functioning within the normal range was reported in about 20% of subjects. On average, medical conditions of potential causal significance were found in 6% of subjects with autism, with tuberous sclerosis having a consistently strong association with autism. Social class and immigrant status did not appear to be associated with autism. There was no evidence for a secular increase in the incidence of autism. In eight surveys, rates for other forms of pervasive developmental disorders were two to three times higher than the rate for autism.
Based on recent surveys, a minimum estimate of 18.7/10000 for all forms of pervasive developmental disorders was derived, which outlines the needs in special services for a large group of children.
Abstract Background Low socioeconomic position predicts risk of substance abuse, yet few studies tested the role of preexisting familial and individual characteristics. Methods Data come from the ...TEMPO (Trajectoires Epidémiologiques en Population) study (community sample in France, 1991–2009, n = 1103, 22–35 years in 2009) set up among offspring of participants of an epidemiological study (GAZEL). Past 12-month substance use was assessed in 2009 by self-completed mail survey: regular tobacco smoking, alcohol abuse (AUDIT), cannabis use, problematic cannabis use (CAST), other illegal drug use. Socioeconomic position was defined by educational attainment, occupational grade, employment stability and unemployment. Covariates included demographics (age, sex, relationship status, parenthood), family background (parental income, parental tobacco smoking, parental alcohol use), and juvenile characteristics (psychological problems, academic difficulties) measured longitudinally. Results 35.8% of study participants were regular smokers, 14.3% abused alcohol, 22.6% used cannabis (6.3% had problematic cannabis use) and 4.1% used other illegal drugs. Except for alcohol abuse, substance use rates were systematically higher in individuals with low, rather than intermediate/high, socioeconomic position (age and sex-adjusted ORs from 1.75 for cannabis use to 2.11 for tobacco smoking and 2.44 for problematic cannabis use). In multivariate analyses these socioeconomic disparities were decreased, but remained statistically significant (except for illegal drugs other than cannabis). Conclusions Tobacco smoking, alcohol, cannabis and polysubstance use are common behaviors among young adults, particularly those experiencing socioeconomic disadvantage. Interventions aiming to decrease substance abuse and reduce socioeconomic inequalities in this area should be implemented early in life.
The Changing Epidemiology of Autism Fombonne, Eric
Journal of applied research in intellectual disabilities,
December 2005, Letnik:
18, Številka:
4
Journal Article
Recenzirano
This article reviews epidemiological studies of autism and related disorders. Study designs and sample characteristics are summarized. Currently, conservative prevalence estimates are: 13/10000 for ...autistic disorder, 21/10000 for pervasive developmental disorders not otherwise specified, 2.6/10000 for Asperger disorder, and 2/100000 for childhood disintegrative disorder. Newer surveys suggest that the best estimate for the prevalence of all autistic spectrum disorders is close to 0.6%. A detailed analysis of time trends in rates of pervasive developmental disorders in then provided. It is concluded that most of the increase is accounted for by changes in diagnostic concepts and criteria, and by improved identification. Whether or not there is, in addition to these factors, a true increase in the incidence of the disorder cannot be examined from available data.
Genetic risk factors for autism spectrum disorder (ASD) have yet to be fully elucidated. Postzygotic mosaic mutations (PMMs) have been implicated in several neurodevelopmental disorders and ...overgrowth syndromes. By leveraging whole-exome sequencing data on a large family-based ASD cohort, the Simons Simplex Collection, we systematically evaluated the potential role of PMMs in autism risk. Initial re-evaluation of published single-nucleotide variant (SNV) de novo mutations showed evidence consistent with putative PMMs for 11% of mutations. We developed a robust and sensitive SNV PMM calling approach integrating complementary callers, logistic regression modeling, and additional heuristics. In our high-confidence call set, we identified 470 PMMs in children, increasing the proportion of mosaic SNVs to 22%. Probands have a significant burden of synonymous PMMs and these mutations are enriched for computationally predicted impacts on splicing. Evidence of increased missense PMM burden was not seen in the full cohort. However, missense burden signal increased in subcohorts of families where probands lacked nonsynonymous germline mutations, especially in genes intolerant to mutations. Parental mosaic mutations that were transmitted account for 6.8% of the presumed de novo mutations in the children. PMMs were identified in previously implicated high-confidence neurodevelopmental disorder risk genes, such as CHD2, CTNNB1, SCN2A, and SYNGAP1, as well as candidate risk genes with predicted functions in chromatin remodeling or neurodevelopment, including ACTL6B, BAZ2B, COL5A3, SSRP1, and UNC79. We estimate that PMMs potentially contribute risk to 3%-4% of simplex ASD case subjects and future studies of PMMs in ASD and related disorders are warranted.
Editorial: Is autism overdiagnosed? Fombonne, Eric
Journal of child psychology and psychiatry,
20/May , Letnik:
64, Številka:
5
Journal Article
Recenzirano
Odprti dostop
After attention was drawn in the late 1960s to the poor reproducibility of psychiatric diagnosis between clinicians, methods and procedures used to diagnose psychiatric disorders were greatly ...improved. Sources of variance contributing to the poor reliability of psychiatric diagnosis were identified that included: information variance (how clinicians go about enquiring about symptoms), interpretation variance (how clinicians weigh the observed symptomatology towards diagnostic formulations), and criterion variance (how clinicians arrange symptom constellations to generate specific diagnoses). To improve the reliability of diagnosis, progresses were made in two major directions. First, diagnostic instruments were developed to standardize the way symptoms are elicited, evaluated, and scored. These diagnostic interviews were either highly structured for use in large‐scale studies (e.g. the DIS), by lay interviewers without a clinical background, and with a style of questioning that emphasized adherence to the exact wording of probes, reliance on closed questions with simple response formats (Yes/No) and recording respondents' answers without interviewer's judgment contribution. By contrast, semi‐structured interviews (e.g. the SADS) were designed to be used by clinically trained interviewers and adopted a more flexible, conversational style, using open‐ended questions, utilizing all behavioral descriptions generated in the interview, and developing scoring conventions that called upon the clinical judgment of the interviewer. Second, diagnostic criteria and algorithms were introduced in nosographies in 1980 for the DSM and soon after in ICD. Algorithm‐derived diagnoses could subsequently be tested for their validity using follow‐up, family history, treatment response studies, or other external criteria.
Changes in autism diagnostic criteria found in DSM-5 may affect autism spectrum disorder (ASD) prevalence, research findings, diagnostic processes, and eligibility for clinical and other services. ...Using our published, total-population Korean prevalence data, we compute DSM-5 ASD and social communication disorder (SCD) prevalence and compare them with DSM-IV pervasive developmental disorder (PDD) prevalence estimates. We also describe individuals previously diagnosed with DSM-IV PDD when diagnoses change with DSM-5 criteria.
The target population was all children from 7 to 12 years of age in a South Korean community (N = 55,266), those in regular and special education schools, and a disability registry. We used the Autism Spectrum Screening Questionnaire for systematic, multi-informant screening. Parents of screen-positive children were offered comprehensive assessments using standardized diagnostic procedures, including the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. Best-estimate clinical diagnoses were made using DSM-IV PDD and DSM-5 ASD and SCD criteria.
DSM-5 ASD estimated prevalence was 2.20% (95% confidence interval = 1.77-3.64). Combined DSM-5 ASD and SCD prevalence was virtually the same as DSM-IV PDD prevalence (2.64%). Most children with autistic disorder (99%), Asperger disorder (92%), and PDD-NOS (63%) met DSM-5 ASD criteria, whereas 1%, 8%, and 32%, respectively, met SCD criteria. All remaining children (2%) had other psychopathology, principally attention-deficit/hyperactivity disorder and anxiety disorder.
Our findings suggest that most individuals with a prior DSM-IV PDD meet DSM-5 diagnostic criteria for ASD and SCD. PDD, ASD or SCD; extant diagnostic criteria identify a large, clinically meaningful group of individuals and families who require evidence-based services.
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