4% of Boys and 1% of Girls Aged 8 Years Now Have the Disorder
The Centers for Disease Control and Prevention (CDC) has just released its latest prevalence rate estimates for autism spectrum disorder (ASD). The CDC reports that 1 in 36 or 2.8% of American 8-year-olds has an autism diagnosis. This rate is a 22% increase from the last reporting period (December 2021), when the figure was already astonishingly high at 1 in 44 children. The new prevalence rate reflects an incredible 4-fold increase in the disorder since the CDC started collecting prevalence estimates data in 2000.
The study, published in the March 23, 2023 Morbidity and Mortality Weekly Report, used the Autism and Developmental Disabilities Monitoring (ADDM) Network to estimate the number of 8 year-old-children with ASD in 2020 (birth year 2012) from 11 different areas, including Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin. ASD prevalence per 1,000 children aged 8 years ranged from a low (23.1) in Maryland to a high (44.9) in California. For the second time, the ADDM Network recognized California as having the highest autism rates in the country. Also reported was the staggering fact that nearly 7% of all 8-year-old boys in the San Diego region have the disorder.
Overall, the report showed that amongst 8-year-olds in 2020, 4% of boys and 1% of girls have autism. ASD remains more prevalent in boys than girls by 3.8 times, a figure that has stayed relatively stable over the past reporting periods. For the first time, ASD prevalence was lower among non-Hispanic White (White) children than among other racial/ethnic groups. This is the opposite of racial and ethnic differences observed in previous ADDM reports. Unfortunately, Black children with ASD were still more likely than White children with ASD to have a co-occurring intellectual disability. The report also discovered that higher ASD rates were associated with lower income at three sites.
A total of 4,164 children with ASD had information on cognitive ability. Of this group, 37.9% were classified as having an intellectual disability, based on the intelligence quotient (IQ) score <70. Data extrapolated from this ADDM report shows that 8-year-olds with an IQ <70 are the most rapidly rising cohort. This group now equals the higher IQ group (85+). When combining the two lower IQ groups (70-85 and <70), an accelerated increase is observed, dispelling the notion that the driver of autism prevalence increases is due to the recognition of children considered high-functioning or having Aspergers Syndrome. Overall, this report shows that all IQ groups are experiencing rising rates.
The authors conclude that additional analyses are needed to understand changing patterns in ASD prevalence and differences between groups. For instance, they point out that in 2010 higher income was associated with higher ASD prevalence. However, the present findings discovered a higher ASD prevalence among lower socioeconomic status neighborhoods.
In the meantime, families who have older children with autism are deeply saddened and extremely frustrated that no meaningful efforts have occurred in the 23 years since the ADDM Network started reporting prevalence rates to curb the continuing autism epidemic.
