Increased Screen Time at 1 Year May Be Linked to Developmental Delay

Earlier this month, an article published in JAMA Pediatrics linked screen time with an increased potential for developmental delays. Researchers set out to understand the dose–response relationship between screen time exposure at 1 year old and developmental advancements when children reach 2 and 4 years old.

The cohort study was conducted under the Tohoku Medical Megabank Project Birth and the Three-Generation Cohort Study to identify 7,097 mother–child pairs. Women across 50 obstetrics clinics in Japan were recruited between July 2013 and March 2017, but data analysis was conducted in March 2023.

Screen time at 1 year old was divided into four different categories: less than 1 hour, 1–2 hours, 2–4 hours, and over 4 hours of screen time per day.

Researchers used a Japanese version of the third edition of the Ages and Stages Questionnaires to evaluate developmental delays. These surveys assess a child’s development in five domains, including communication, gross motor, fine motor, problem-solving, and personal or social skills, at 2 and 4 years old. Each part is scored on a scale of 0–60.

Approximately 3,440 children, or 48.5% of study participants, had less than 1 hour of screen exposure. Roughly 29.5% of participants had 1–2 hours of daily screen exposure, and 17.9% were exposed to 2–4 hours. Finally, only 4.1% of participants had over 4 hours of screen exposure.

Participants who had 1–2 hours of screen exposure were 61% more likely to have a communication developmental delay at 2 years old than those who had less than 1 hour of screen time. Communication delay risk doubled for those with 2–4 hours of screen exposure. Finally, over 4 hours of screen time was linked to a 4.78 times greater risk of communication delays.

Other affected factors included fine motor skills, which were 74% more likely to occur with over 4 hours of exposure than less than 1 hour. Problem-solving delays increased by 40% in patients with 2–4 hours of exposure. Over 4 hours of exposure increased problem-solving delays by 2.67 times.

Personal and social skills were 2.10 times more likely in 2 year olds exposed to over 4 hours of screen time when they were 1.

Focusing on the development for 4 year olds, communication skills were 64% more likely to be delayed when participants were exposed to 2–4 hours of screen time, and over 4 hours of screen time increased the risk of communication delays at 4 years old by 2.86 times. Finally, problem-solving skills at 4 years old were 91% more likely to be delayed with over 4 hours of screen exposure.

Researchers in the publication concluded that “greater screen time for children aged 1 year was associated with developmental delays in communication and problem-solving at ages 2 and 4. These findings suggest that domains of developmental delay should be considered separately in future discussions on screen time and child development.”