New research shows that children who watch more television sleep less, illuminating a possible indirect factor behind a variety of health and emotional problems.

Dr. Marcella Marinelli, a researcher at the Center for Research in Environmental Epidemiology in Barcelona and lead author of the new study, said that the results confirm a long-held suspicion that television and sleep don’t go well together. “Children spending longer periods watching television had shorter sleep duration,” she and her colleagues wrote. “Parents should consider avoiding long periods of daily television exposure among preschool and school-aged children.”

The study, which is published in the journal JAMA Pediatrics, surveyed 1,731 children ages 6 to 9. Parents were asked to estimate how many minutes per day their child spent watching television and how many hours of sleep they usually got. The researchers also examined factors like physical activity levels and ADHD symptoms.

They found that children who watched television for 1.5 hours a day had significantly shorter sleep durations compared to kids who watched less. “We observed an inverse association between time spent watching television and sleep duration,” the team wrote in their conclusion.

Children and Sleep

The study dovetails with several other recent studies examining the relationship between sleep and general health. Earlier this year, researchers at Harvard University showed that more sleep may lower your risk of developing prostate cancer. Another study from Northwestern Medicine found that sleep may help people overcome phobias.

For children, sleep is particularly important, as inadequate rest may put them at risk of numerous health issues. For example, kids who don’t get enough sleep are more likely to develop metabolic complications like diabetes and obesity. They also have an elevated risk of receiving psychiatric diagnoses.

“Insomnia is a significant risk factor for depression,” Psych Central explains. “It also contributes to anxiety by raising cortisol, the stress hormone.”

Sleep-deprived children are typically bad news to people around them, too. Studies show that children with less than ideal rest patterns are more prone to bicycle injuries and playground accidents. “A tired child is an accident waiting to happen,” says Dr. Carl Hunt, director of the National Center on Sleep Disorders Research.

Source: Marinelli M, Sunyer J, Alvarez-Pedrerol M, et al. Hours of Television and Sleep Duration in Children: A Multicenter Birth Cohort Study. JAMA Pediatrics. 2014.