About 1 in 3 Toddlers With Autism ‘Outgrow’ Disorder: Study

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Oct. 11, 2023 – More than a third of toddlers diagnosed with autism spectrum disorder outgrew the disorder by the time they were about 6 years old, according to a new study from Boston Children’s Hospital researchers.

The findings were published this month in JAMA Pediatrics. The study included 213 children who were diagnosed with autism spectrum disorder (ASD) when they were between the ages of 1 and 3 years old. On average, the children were diagnosed around 2½ years old, and 83% of those in the study were boys.

All of the children in the study received interventions based on the diagnosis. The most common intervention used was applied behavior analysis, which is a therapy that focuses on increasing helpful behaviors and decreasing unhelpful ones. Applied behavior analysis can teach people to improve skills in areas like communication, attention, focus, and socializing.

The children in the study were re-evaluated for ASD between the ages of 5 and 7 years old. The evaluations occurred between 2018 and 2022. 

By the time the children reached about 6 years old, 37% of them no longer met the criteria for ASD. The 79 children in the study who outgrew ASD were more likely to be girls or to have what researchers called “higher baseline adaptive functioning,” compared to those who didn’t outgrow the disorder. The term “baseline adaptive functioning” refers to essential everyday skills like communication, self-care, and decision-making. 

“It is possible that children who no longer have autism at age 6 may have responded better to treatment than children whose autism persisted,” study co-author William Barbaresi, MD, chief of developmental medicine at Boston Children’s Hospital, said in a statement. “The findings of the study should cause a very frank reconsideration of the need for far more research to understand if current treatment for autism is working, or if major new efforts to develop treatment approaches are needed.”

The children whose ASD did not continue all had an IQ score of 70 or higher. IQ scores of 70 to 75 indicate a significant limitation in intellectual function, according to the American Psychiatric Association, while a score below 70 is considered a sign of an intellectual disability. 

ASD is a developmental disability that typically can be diagnosed before age 3 and impacts the brain in ways that cause people to behave, communicate, interact, and learn differently than others. As people with ASD get older, they can have a variety of challenges, such as hard times in relationships or understanding what is expected in school or on the job, according to the CDC. ASD rates have been on a dramatic rise in recent years, with about 1 in 36 children being diagnosed with the disorder by the time they are 8 years old, recently published data from 2020 shows.

The findings in this latest study show that parents of children diagnosed with ASD need to remain open-minded, said lead author Elizabeth Harstad, MD, MPH, attending physician in developmental medicine at Boston Children’s Hospital.

“It is important to recognize that diagnoses can evolve as a child develops,” she said in a statement. “Our research shows how important it is that we monitor kids over time, because some children may really have changes in their social communication and behavioral function. This underscores the need for continuous assessments and adaptable intervention strategies."