While rates of ASD are consistent across cultures, they vary greatly by gender, with boys diagnosed far more frequently than girls. The average male-to-female diagnosis ratio for ASD is 4.2:1, with 1 in 70 boys, but only 1 in 315 girls. Girls, however, are more likely to have associated cognitive impairment, suggesting that less severe forms of ASD are likely being missed in girls and women. Among those with an ASD and intellectual disability, the sex ratio may be closer to 2:1. Prevalence differences may be a result of gender differences in expression of clinical symptoms, with women and girls with autism showing less atypical behaviors and, therefore, less likely to receive an ASD diagnosis. Autism prevalence has been estimated at 1–2 per 1,000, Asperger syndrome at roughly 0.6 per 1,000, childhood disintegrative disorder at 0.02 per 1,000, and PDD-NOS at 3.7 per 1,000. These rates are consistent across cultures and ethnic groups, as autism is considered a universal disorder. Using DSM-5 criteria 92% of the children diagnosed per DSM-IV with one of the disorders which is now considered part of ASD will still meet the diagnostic criteria of ASD. However, if both ASD and Social Communication Disorder categories of DSM-5 are combined, the prevalence of autism is mostly unchanged from the prevalence per the DSM-IV criteria. The best estimate for prevalence of ASD is 0.7% or 1 child in 143 children. Relatively mild forms of autism, such as Aspergers as well as other developmental disorders were included in the recent DSM-5 diagnostic criteria. ASD rates were constant between 2014 and 2016 but twice the rate compared to the time period between 2011 and 2014 (1.25 vs 2.47%). A Canadian meta-analysis from 2019 confirmed these effects as the profiles of people diagnosed with autism became less and less different from the profiles of the general population. In the US, the rates for diagnosed ASD have been steadily increasing since 2000 when records began being kept. While it remains unclear whether this trend represents a true rise in incidence, it likely reflects changes in ASD diagnostic criteria, improved detection, and increased public awareness of autism. United States In the United States it is estimated to affect more than 2% of children (about 1.5 million) as of 2016. According to the latest CDC prevalence reports, 1 in 44 children (2.3%) in the United States had a diagnosis of ASD in 2018. Prevalence is estimated at 6 per 1,000 for ASDs as a whole, although prevalence rates vary for each of the developmental disorders in the<unk> .
Autism spectrum
Tardive dysmentia
Outline of autism
Nonverbal autism
Multiple complex developmental disorder
High-functioning autism
Low-functioning autism
Zellweger spectrum disorders