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. Autism Res 2012, 5: 160–179. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

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Global Prevalence of Autism and Other Pervasive Developmental Disorders

Prevalence of autistic spectrum disorders (ASD) in Oman is unknown. We conducted a cross-sectional study to estimate the prevalence of ASD among 0-14 year old children. Diagnoses were made as per DSM-IV-TR criteria and supplemented with information collected with the standard Childhood Autism Rating Scale (CARS) questionnaire. A total 113 cases of ASD were enumerated nationwide, indicating an overall prevalence of 1.4 (95% CI 1.2, 1.7) cases per 10,000 children aged 0-14 years. More prevalent cases were among boys (75%) and among low-income families. Ritualistic interests were more common among girls as an onset-symptom compared to boys (p = 0.03). The reported low prevalence of ASD in Oman is likely due to under-diagnosis and under-reporting.

Brief Report: Prevalence of Autistic Spectrum Disorders in the Sultanate of Oman

Objective
The objective of this review was to examine prevalence and patterns of psychopharmacotherapy in individuals with autism spectrum disorder (ASD).

Method
A systematic literature search in PubMed, CINAHL, and PsycINFO was performed, including articles published up to November 18, 2015.

Results
A total of 47 studies (data collection: 1976–2012), encompassing >300 000 individuals with ASD, were included. The prevalence of psychopharmacotherapy ranged from 2.7% to 80% (median (overall): 45.7%; median (children): 41.9%; median (adults): 61.5%), with psychotropic polypharmacy occurring in 5.4–54% (median: 23.0%). Regarding drug classes, antipsychotics were most frequently used, followed by attention-deficit/hyperactivity disorder (ADHD) medication and antidepressants. Both older age and psychiatric comorbidity were associated with higher prevalences of psychopharmacotherapy and psychotropic polypharmacy. There were no time trends in psychopharmacotherapy prevalence observable.

Conclusion
Despite a lack of pharmacological treatment options for ASD core symptoms, the prevalence of psychopharmacotherapy and polypharmacy in ASD patients is considerable, which is probably due to the treatment of non-core ASD symptoms and psychiatric comorbidities. While there is some evidence for the use of antipsychotics and ADHD medication for these indications, the use of antidepressants should be limited to selected cases.

Use of psychotropic drugs in patients with autism spectrum disorders: a systematic review

Psychopathology, families, and culture: autism.

An essential guide to this major contemporary issue, Consanguinity in Context is a uniquely comprehensive account of intra-familial marriage. Detailed information on past and present religious, social, and legal practices and prohibitions is presented as a backdrop to the preferences and beliefs of the 1100+ million people in consanguineous unions. Chapters on population genetics, and the role of consanguinity in reproductive behaviour and genetic variation, set the scene for critical analyses of the influence of consanguinity in the early years of life. The discussion on consanguinity and disorders of adulthood is the first review of its kind and is particularly relevant given the ageing of the global population. Incest is treated as a separate issue, with historical and present-day examples examined. The final three chapters deal in detail with practical issues, including genetic testing, education and counselling, national and international legislation and imperatives, and the future of consanguineous marriage worldwide.

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Consanguinity in Context

Although autism is a global disorder, relatively little is known about its presentation and occurrence in many developing countries, such as Saudi Arabia. This article describes the reasons for referral and clinical characteristics of a sample of 49 children (37 males and 12 females) diagnosed with an autistic spectrum disorder at a tertiary referral center in Saudi Arabia. The diagnosis of autism was based on DSM-IV criteria supplemented by information obtained from parent and child interviews, rating scales, and examination of school and hospital records. Females were older than males at the time of referral. Eleven patients had a history of seizure disorder and one patient had a chromosome abnormality. Twenty-five patients were taking psychotropic medications and 14 patients were the product of consanguineous marriages. Clinical and research implications of these findings are discussed.

https://journals.sagepub.com/doi/pdf/10.1177/1363461509105823

Autism in Saudi Arabia: presentation, clinical correlates and comorbidity.

Autism is a neurodevelopmental disorder characterized by a pattern of social and communication deficits. Although it occurs in all cultures and countries, most of the published research has come from Western industrialized countries. In particular, relatively little is known about its clinical correlates and comorbidity in African and Middle Eastern countries. In this paper, we report two cases of G6PD deficiency with autism, recruited as part of a larger study on the occurrence of autism in Saudi Arabia. These findings suggest that a different set of medical conditions may be associated with autism in developing countries.

Saleh M. Al-Salehi

Papers

Autism in Saudi Arabia: presentation, clinical correlates and comorbidity.

G6PD deficiency in autism: a case-series from Saudi Arabia