Too much screen time can impair brain structure and function. It can cause obesity, insomnia, mood swings and even problems at school. Because child brain undergo so much change during their formative years, this excess screen time can be even more damaging.

Excessive screen-time linked to changes in preschoolers’ brains. Children who used screens for long periods on a daily basis were found to have lower structural integrity between the connections found in white matter – the parts of the brain that support language and literacy skills.

MRI scans found significant differences in the brains of some children who reported using smartphones, tablets, and video games more than seven hours a day. Children who reported more than two hours a day of screen time got lower scores on thinking and language tests.

ScreenQ Scores

Researchers found that kids with higher ScreenQ scores had lower expressive language, lessened ability to quickly name objects and overall literacy skills. Among the key findings:

  • Higher ScreenQ scores were significantly associated with lower expressive language, the ability to rapidly name objects (processing speed) and emergent literacy skills.
  • Higher ScreenQ scores were associated with lower brain white matter integrity, which affects organization and myelination — the process of forming a myelin sheath around a nerve to allow nerve impulses to move more quickly — in tracts involving language executive function and other literacy skills.
Parenting: Lateral brain image of a child exposed to significant screen time.
This lateral brain image of a child exposed to significant screen time shows lower level levels of white matter structural integrity. These affected areas are in blue.

Study published in JAMA Pediatrics, shows that children who have more screen time have lower structural integrity of white matter tracts in parts of the brain that support language and other emergent literacy skills. These skills include imagery and executive function – the process involving mental control and self-regulation. These children also have lower scores on language and literacy measures.

Cravings and impaired dopamine function: Research on video games have shown dopamine is released during gaming (Koepp 1998 and Kuhn 2011) and that craving or urges for gaming produces brain changes that are similar to drug cravings (Ko 2009, Han 2011).

How much screen time is okay for kids?

It’s hard to say what the ‘safe’ age or amount of screen time is, Dr John Hutton says. “My motto is ‘Screen-free until three’—this at least gets kids to preschool with a solid anchor in the real world, where their basic sense of connection with caregivers and early language skills have solidified.”

Pediatrics recommends the following:

  • Children younger than 18 months only use screens when it’s used for video chatting.
  • Age under 2 years old: Should not be exposed to any screen time including TV, smartphones and tablets.
  • Children aged 2 to 4 years old: Screen time limited to less than one hour a day.
  • Aged 5 and above: No more than two hours daily of recreational screen time.


  1. John S. Hutton, Jonathan Dudley, Tzipi Horowitz-Kraus, Tom DeWitt, Scott K. Holland. Associations Between Screen-Based Media Use and Brain White Matter Integrity in Preschool-Aged Children
  2. USA today