Clinical relevance: UCL researchers reviewed studies on 237 adolescents and found internet addiction significantly alters brain function, affecting behavior and mental health.

  • Internet addiction disrupts neural networks, decreasing activity in the executive control network responsible for decision-making.
  • Adverse effects include trouble maintaining relationships, dishonesty about online activity, and irregular eating and sleeping patterns.
  • Researchers call for better screening, targeted treatments, and parental education to manage screen time and mitigate risks.

A new study sheds light on the profound impact of internet addiction on the brains of young people. And it’s as bad as we feared.

The University College London researchers  – whose paper appears in PLOS Mental Health – reviewed a dozen articles involving 237 adolescents aged between 10 and 19 diagnosed with internet addiction between 2013 and 2023. And the findings provide some new insight into how excessive internet use alters brain function and – as a result – behavior.

Defining – and Observing – Internet Addiction

Scientists classify internet addiction as an inability to control internet use, which threatens one’s psychological well-being, including their social, academic, and professional lives.

The studies that researchers reviewed for this paper all relied on magnetic resonance imaging (fMRI) to examine the functional connectivity of the brains of participants both at rest and during task performance – or, in this case, internet use.

The findings exposed notable changes in multiple neural networks within the brains of adolescents suffering from an internet addiction. The researchers observed a mix of increased and decreased activity in the default mode network, which is typically active during rest. 

Conversely, the team observed an appreciable drop in functional connectivity within the executive control network, which is responsible for active thinking and decision-making.

The researchers noted a link between these alterations and addictive behaviors and tendencies among adolescents. They also observed other changes that appeared to affect intellectual ability, physical coordination, mental health, and development. 

Max Chang, the lead author and UCL student, stressed how vulnerable adolescents are at this time.

“Adolescence is a crucial developmental stage during which people undergo significant changes in their biology, cognition, and personalities,” Chang explained. “As a result, the brain is particularly susceptible to internet addiction-related urges during this time, such as compulsive internet usage and cravings towards media consumption.”

From Bad to Worse

Chang also highlighted other potential adverse behavioral and developmental consequences stemming from internet addiction, such as:

  • Trouble maintaining relationships.
  • Dishonesty about online activity.
  • Irregular eating and sleeping patterns.

The growing accessibility of smartphones and laptops has only made things worse. Earlier research suggested that UK citizens, for example, spend at least 24 hours online every week. And more than half of those surveyed described themselves as addicted to the internet.

Additionally, Ofcom, the United Kingdom’s communications regulator, has reported that more than 60 percent of the country’s 50 million internet users are convinced that their internet usage makes their lives worse, such as causing tardiness or neglecting chores.

Senior author Irene Lee, from UCL’s Great Ormond Street Institute of Child Health, acknowledged the benefits of the internet but warned against its detrimental effects.

“When internet use begins to affect our daily lives, it becomes a problem,” Lee said. “We advise young people to set sensible time limits for daily internet usage and be mindful of the psychological and social implications of excessive time online.”

Chang seemed confident that the study’s findings would help medical professionals step up screening efforts so that they could better treat internet addiction in adolescents. The researchers added that potential treatments could target specific brain regions, or involve psychotherapy or family therapy.

Additionally, Chang emphasized how important it is for caregivers to educate parents about internet addiction so that they can be better equipped to manage screen time at home – and reduce risk factors.

The study’s authors concluded with a call for a more proactive approach to tackle the growing issue of internet addiction among adolescents, highlighting the need for awareness, prevention, and better intervention strategies.

Further Reading

Teenagers Appear to be ‘Spreading’ Mental Illness

Teen Vaping and Mental Health

Social Media Really is a Nightmare