This week, news outlets across the world reported a study from the Journal of the American Medical Association (JAMA) linking digital media exposure to reduced attention spans and attention deficit/hyperactivity disorder (ADHD):
But while the study found a link between high rates of digital media use and inattention and hyperactivity, it didn’t find that one caused the other.
Nor did it look specifically at clinically diagnosed ADHD – it used a survey to ask students about ADHD-related symptoms.
What is ADHD?
ADHD is a neurodevelopmental disorder, which means it originates in early childhood and affects the brain’s development. Around 7.2% of children worldwide have a diagnosis of ADHD.
Symptoms include inattentive, hyperactive and impulsive behaviour. Although characteristic of ADHD, these behaviours exist on a continuum. So attention difficulties can be experienced, though at a lesser degree, by children and adolescents who don’t have ADHD.
These behaviours may fluctuate due to factors such as age (they’re more common in childhood) and levels of stress.
How was the study conducted?
The new JAMA study, from researchers at the University of Southern California, investigated the link between digital media use and the development of ADHD-related behaviours among 15- and 16-year-olds.
Just over 2,500 Californian high school students without ADHD completed a survey about their frequency of digital media use: many times a day, 1-2 times a day, 1-2 times a week, never.
What did they find?
Most students (80.9%) reported high-frequency use (three or more times a day) of at least one type of digital media. Checking social media sites was the most common, with 54% of the teens checking in many times a day.
Over the first six months of the study, 6.9% of students reported they had experienced ADHD symptoms. This rate dropped to 5.9% over the last six months of the study.
Teens who reported no high-use digital media activity had lower rates of experiencing ADHD-related behaviour over the 24-month study period, at a rate of 4.6%.
High-frequency engagement with more digital activities was associated with higher odds of experiencing ADHD-related behaviour. Among those who reported high use of seven activities, 9.5% experienced ADHD-type behaviours. Those reporting high use of all 14 digital media activities had the highest rates, at 10.5%.
Not all high-frequency digital media activities were associated with ADHD symptoms. Texting, chatting online, playing games with friends or family on a console, computer or smartphone, and posting photos or blogs had no association.
Activities that had the strongest association with ADHD symptoms include a high frequency of checking of social media sites, liking or commenting on other statuses, playing games alone on a console, computer or smartphone, and video chatting.
Two other factors – delinquent behaviour and depressive symptoms – were associated with higher rates of ADHD-related behaviours. But the link between high frequency of use of digital media and higher odds of ADHD symptoms held, even when taking these other factors into account.
What does it all mean?
This study highlights a potential association between digital media and behavioural symptoms typically associated with ADHD. But this work is unable to show causation.
It’s not possible to determine whether digital media use exacerbates ADHD-related behaviour, or whether those with ADHD-related behaviours find digital media more attractive, and use it more frequently.
Despite a link between digital media use and behaviours that are common in ADHD, ADHD is a complex neurodevelopmental disorder, and these findings in no way suggest digital media can cause ADHD.
There is a strong genetic basis for ADHD. In other words, people with the disorder are more likely than their peers to have parents and siblings with ADHD.
It’s also important to note an increase in inattention and hyperactivity in adolescence does not mean the young person would be diagnosed with ADHD.