Too Much Internet Use Is Changing Teenage Brains, Study Finds

Excessive use of the internet is reshaping teenage brains, according to a new study.

Scans show that the brains of teenagers who are addicted to the internet undergo changes in the parts of the brain involved in active thinking.

These were found to lead to additional addictive behavior, as well as changes associated with intellectual ability, physical co-ordination, mental health and development, according to researchers at University College London, who carried out the study.

“Adolescence is a crucial developmental stage during which people go through significant changes in their biology, cognition, and personalities,” said Max Chang, a masters student at the UCL Great Ormond Street Institute for Child Health and lead author of the study.

“As a result, the brain is particularly vulnerable to internet addiction related urges during this time, such as compulsive internet usage, cravings towards usage of the mouse or keyboard and consuming media.”

Researchers looked at 12 studies where functional magnetic resonance imaging (fMRI) scans had been carried out on the brains of a total of 237 young people aged 10 to 19 formally diagnosed with internet addiction, defined as an inability to resist the urge to use the internet to the extent it negatively impacts their wellbeing, as well as their social, academic and professional lives.

The scans found both increased and decreased activity in parts of the brain activated when resting, and an overall decrease in functional connectivity — how regions of the brain interact with each other — in the parts involved in active thinking, the executive control network.

The impact is similar to that resulting from drug-use and gambling addiction, the researchers found.

The implications for adolescent behavior are significant, according to the study, published in the peer-reviewed journal PLOS Mental Health.

Among the functions affected by a decline in functional connectivity are physical co-ordination, short-term memory, impulse control, attention span, decision-making, motivation, response to rewards and processing information.

Changes to the brain during adolescence make it particularly vulnerable to the impact of internet addiction, researchers say.

“The findings from our study show that this can lead to potentially negative behavioral and developmental changes that could impact the lives of adolescents,” Chang said.

“For example, they may struggle to maintain relationships and social activities, lie about online activity and experience irregular eating and disrupted sleep.”

Researchers caution that the use of fMRI scans to investigate internet addiction is limited, so the number of studies involving adolescents is relatively small. Most of the studies were carried out in Asia, and future research should compare results from Western countries, they add.

Nevertheless, the findings will add to concern about the impact of the internet and smartphone use on children and young people.

Only last month, a committee of U.K. lawmakers warned that a ban on under 16s using smartphones may be the best option to limit the damage they could cause.

More than three quarters of 10-15-year-olds in England and Wales spend three hours or more online at weekends, with one in five (22%) online for seven hours or more, and around half online for three hours plus on a school day, according to one survey.

In the U.S., almost half of teens say they use the internet “almost constantly”, according to a 2022 report by the Pew Research Center.

“There is no doubt that the internet has certain advantages,” said Irene Lee, of the UCL Great Ormond Street Institute of Child Health and senior author of the study.

“However, when it begins to affect our day-to-day lives, it is a problem.”