title: Global prevalence of autism and other pervasive developmental disorders.
abstract: We provide a systematic review of epidemiological surveys of autistic disorder and pervasive developmental disorders (PDDs) worldwide. A secondary aim was to consider the possible impact of geographic, cultural/ethnic, and socioeconomic factors on prevalence estimates and on clinical presentation of PDD. Based on the evidence reviewed, the median of prevalence estimates of autism spectrum disorders was 62/10 000. While existing estimates are variable, the evidence reviewed does not support differences in PDD prevalence by geographic region nor of a strong impact of ethnic/cultural or socioeconomic factors. However, power to detect such effects is seriously limited in existing data sets, particularly in low-income countries. While it is clear that prevalence estimates have increased over time and these vary in different neighboring and distant regions, these findings most likely represent broadening of the diagnostic concets, diagnostic switching from other developmental disabilities to PDD, service availability, and awareness of autistic spectrum disorders in both the lay and professional public. The lack of evidence from the majority of the world's population suggests a critical need for further research and capacity building in low- and middle-income countries.
authors.affiliation: Department of Psychiatry, Montreal Children's Hospital, Montreal, Canada; Birkbeck, University of London, London, UK.
authors.forename: Mayada
authors.initials: M
authors.lastname: Elsabbagh
authors.forename: Gauri
authors.initials: G
authors.lastname: Divan
authors.forename: Yun-Joo
authors.initials: YJ
authors.lastname: Koh
authors.forename: Young Shin
authors.initials: YS
authors.lastname: Kim
authors.forename: Shuaib
authors.initials: S
authors.lastname: Kauchali
authors.forename: Carlos
authors.initials: C
authors.lastname: Marcín
authors.forename: Cecilia
authors.initials: C
authors.lastname: Montiel-Nava
authors.forename: Vikram
authors.initials: V
authors.lastname: Patel
authors.forename: Cristiane S
authors.initials: CS
authors.lastname: Paula
authors.forename: Chongying
authors.initials: C
authors.lastname: Wang
authors.forename: Mohammad Taghi
authors.initials: MT
authors.lastname: Yasamy
authors.forename: Eric
authors.initials: E
authors.lastname: Fombonne
mesh_terms: D001321:Autistic Disorder / Q000453:epidemiology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology*; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D003906:Developing Countries; D014943:Global Health; D006306:Health Surveys; D006801:Humans; D012959:Socioeconomic Factors