Letting a baby watch a smartphone, tablet or TV at 12 months increases the odds the child will develop autism-like symptoms during the next year, new research suggests.
On the other hand, if parents spent active play time with their child every day, the odds of autism-like symptoms decreased.
"At 12 months, watching TV or DVDs was associated with more autism symptoms at 2 years," said study author David Bennett. He's a psychologist in the department of psychiatry at the Drexel University College of Medicine in Philadelphia.
The study didn't include data on definitive autism diagnoses, only symptoms of the disorder, such as a lack of making eye contact or failing to look when someone points or calls your name. And it could not prove that screen time caused autism symptoms.
The researchers noted that their findings may be especially important during the COVID-19 pandemic, as parents may have to work from home while taking care of children at the same time.
"It's hard right now and, hopefully, this will not be going on for months and months. We've been encouraging parents to save their sanity and do what they have to do. But try to play and engage your child more," Bennett said.
One in 54 children has an autism spectrum disorder, according to the U.S. Centers for Disease Control and Prevention. Most cases of autism are believed to have a genetic origin. But, environmental factors may also play a role, the researchers said.
For example, more screen time in very young children may interfere with social learning, and it may alter a child's brain processing. It could cause visual areas of the brain to become overdeveloped, the researchers suggested.
But Bennett said the picture may be more complicated. "Kids with autism are more predisposed to watch screens," he explained. Kids with autism symptoms may use screens as a soothing device, instead of turning to a parent. That may lead a parent to engage less than they would otherwise like to, Bennett explained.
The study was published online April 20 in JAMA Pediatrics.
The researchers relied on data from a previous study that included more than 2,100 children. The kids were enrolled at birth and followed for their first two years. Caregivers answered questions about screen viewing time. Since the data was collected between 2010 and 2012, the screen time was primarily TV and DVD viewing.
Caregivers were also asked to complete an autism checklist. The checklist has 20 questions that could suggest autism-like symptoms.
The study found that if caregivers said a child had screen time at 12 months old, they were 4% more likely to have autism-like symptoms at 2 years. If a parent played with the child daily at 12 months compared to less than daily play, the risk of autism-like symptoms went down by 9%.
Bennett said he believes that if screen habits changed, the risk of autism-like behaviors might decrease. He said the brain in young children may be able to change.
Others aren't so sure that's the case, however.
Dr. Dimitri Christakis, editor-in-chief of JAMA Pediatrics, wrote an accompanying editorial. "I think there's a critical window in brain development in the first two to three years of life. I think the architecture of the mind may be set early," he said.
Christakis said the findings reinforced the American Academy of Pediatrics' recommendation that children under 18 months old shouldn't be on screens at all. Their one exception is video chatting with friends and family.
"Facetime with Grandma doesn't count as screen time," Christakis said.
In kids older than 18 months, he said he would minimize screen exposure as much as you can.
Bennett also said that parents should try to have no screen time for kids under 18 months. And, he added that it's important to remember that "not all screen time is created equally," so parents should keep an eye on what their kids are watching.
Read more about the American Academy of Pediatrics' stance on children and screen time here.