Vol.:(0123456789) 1 3 Journal of Autism and Developmental Disorders https://doi.org/10.1007/s10803-018-3581-2 ORIGINAL PAPER Prevalence and Characteristics of Autism Spectrum Disorder Among Spanish School-Age Children Paula Morales‑Hidalgo 1  · Joana Roigé‑Castellví 1  · Carmen Hernández‑Martínez 1  · Núria Voltas 1  · Josefa Canals 1 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract The present study aims to assess the prevalence of autism spectrum disorder (ASD) in preschool and school-age children following a two-phase procedure. The screening phase was performed on a sample of 5555 children taking into account par- ent and teacher information. The individual assessment included the ADI-R, ADOS-2 and Wechsler scales. The estimated prevalence was 1.55% in preschoolers and 1.00% in school-age children. Between 1.84 and 2.59% of the children exhibited subclinical diagnosis. The male-to-female ratio was around 4:1. Most of the children exhibited mild and moderate nuclear symptoms, and the girls showed less severe communication problems. Previous diagnosis was found in 62–71% of the chil- dren. Prevalence estimates are close to the 1% international ratings and much higher than previous national reports suggested. Keywords Autism spectrum disorders · Epidemiology · Prevalence · School-age children Introduction Described as a continuum for the frst time by Wing and Gould (1979), autism spectrum disorder (ASD) is a group of lifelong neurodevelopmental disorders characterized by qualitative impairments in social communication and inter- action and the presence of restricted, repetitive or stereo- typed patterns of behaviour and interests (American Psychi- atric Association 2013). Clinical presentations of ASD are markedly heterogeneous due to variability in the severity of nuclear autistic impairments and the development of cog- nitive and language abilities, and also because of the high presence of psychopathological comorbidities (Höglund- Carlsson et al. 2013; Salazar et al. 2015). These disorders involve varying but persistent alterations throughout the lifespan and a signifcant impairment in social, school and family functioning that require substantial support for the children and their family environment. However, the high variability in its presentation often makes diagnosis difcult. The worldwide prevalence of ASD has increased in recent decades (Elsabbagh et al. 2012; Hansen et al. 2015; Idring et al. 2015), reaching values of between 0.7 and 1.5% in childhood and adolescence (Baron-Cohen et al. 2009; Baird et al. 2006; Bent et al. 2015; CDC 2014; Christensen et al. 2016; Nygren et al. 2012; Saemundsen et al. 2013; Sun et al. 2015). Current prevalence estimates difer greatly from those presented in early European epidemiological studies, which reported rates of between 1.9/10,000 and 72.6/10,000 (Belinchón 2001; Elsabbagh et al. 2012; Garanto 1994; Orte et al. 1995) on the basis of registers and narrow defnitions of autism. However, prevalence estimates also diverge to a great extent among studies from diferent countries, ranging from values of under 0.2% in China and Italy (Ferrante et al. 2015; Wan et al. 2013) up to the 2.7% claimed by Kim et al. (2011) in South Korea. The rates found in central and southern European coun- tries such as Italy, Germany, Denmark, France, Spain and Poland are much lower, with estimates around 0.1–0.6% (Aguilera et al. 2007; Bachmann et al. 2016; Ferrante et al. * Josefa Canals josefa.canals@urv.cat Paula Morales-Hidalgo paula.morales@urv.cat Joana Roigé-Castellví joana.roige@urv.cat Carmen Hernández-Martínez carmen.hernandez@urv.cat Núria Voltas nuria.voltas@urv.cat 1 Department of Psychology, Nutrition and Mental Health Research Group (NUTRISAM), Research Center for Behavioral Assessment (CRAMC), Universitat Rovira i Virgili, Ctra. Valls s/n, 43007 Tarragona, Spain