A recent release from the CDC estimates that 1 in 88 American children born in 2000 has been identified as having an autism spectrum disorder (ASD), a 23% increase since their 2009 report. They attribute at least some of the increase to greater awareness and diagnosis, especially among minority children. However, increased screening and diagnoses do not account for all of the increase. Among the sample population, 44% of children had Autistic Disorder, 47% had Autism Spectrum Disorders/Pervasive Developmental Disorder, and 9% had Asperger Disorder. ASDs affect almost five times as many boys as girls. No single cause of autism is known, although children born prematurely or to older parents are at slightly higher risk.
Another study identified ten signs of possible autism in children between six and twelve months, including rarely smiling at caregivers and poor eye contact. Common signs among older toddlers include not playing “pretend” games by 18 months, delayed speech, and having trouble understanding others’ feelings. Current recommendations are that all children be screened for autism by age 2, as early diagnosis and intervention can lead to better outcomes.
A study of children born between 1992 and 2001 found that around 10% children with the diagnosis, labeled “bloomers”, move from low functioning in early childhood to high functioning after puberty, with some even no longer fitting the diagnosis for ASD. These children were more often diagnosed before age 3, more likely to have higher-educated, non-minority mothers, and were less likely to have a intellectual disability than children of other trajectories. These findings support other research that some children diagnosed with ASDs will grow out of the diagnosis. The authors suggest that these children might be able to advocate for intervention services for their children.