Study Finds Alterations in Functional Connectivity of Brain Regions in Adolescents With Internet Addiction

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According to a study published in PLOS Mental Health, an addiction to the internet is associated with disrupted signaling in the regions of the brain that are involved in multiple neural networks, and therefore, have an impact on mental health. These networks, noted the authors, have a significant role in controlling attention in association with intellectual ability, physical coordination, working memory, and emotional processing.¹

With internet use increasing, adolescents are spending more time online. Because adolescent brains are more capable of changing than their adult counterparts, the researchers wanted to further understand how the effects of internet addiction on the brain can be vital.¹

For this study, the investigators utilized functional magnetic resonance imaging (fMRI) studies to investigate potential consequences of internet addiction on the functional connectivity (FC) in the adolescent brain, as well as its effects on behavior and development. A systematic search was conducted from 2 databases, PubMed and PsycINFO, of which 12 articles were selected. Most of the articles, according to the investigators, utilized resting fMRI techniques (n = 7), with 3 demonstrating task-based fMRI procedures and the remaining 2 utilizing whole-brain imaging measures. Sample sizes in the individual studies ranged from 12 to 31 adolescents. Additionally, 8 of the studies included a mix of male and female participants, however, 3 included only males and 1 did not disclose the sex of the participants. The included studies were conducted from 2013 to 2022, most of which were from 2013 to 2015 (2013: n = 2; 2014 and 2015: n = 3 each).²

The findings demonstrate that the specific effects of internet addiction on the adolescent brain are not entirely clear because of the variety of FC changes; however, there are overarching behavioral, network, and developmental trends that were supported that provided insight on adolescent development. The results found that regions of the brain affected by internet addiction are widespread and influence multiple networks including the default mode network (DMN), executive control network (ECN), salience network (SN), and reward pathway. Notably in the DMN, there was a complex mix of increases and decreases observed; however, the findings of SN and reward pathway were not completely clear. The FC changes within adolescents with internet addiction overall were network specific and presented a foundation to better understand behavior changes resulting from internet addiction.²

Further, the authors also emphasized the importance of network interactions in the continuation of internet addiction and the development of its behavioral symptoms. They observed that DMN, SN, ECN, and reward system all contributed to reward valuation, impulsivity, salience to stimuli, cue reactivity, and other changes that alter behavior toward internet use. Many of these changes, according to the authors, are connected to the integral nature of the adolescent brain.²

According to the investigators, the adolescent brain is very responsive to synaptic reorganization and experience cues. Because of this, one of the notable traits of adolescent brain maturation is the variation in neural network trajectory, and important weaknesses may explain the neurobiological changes resulting from external stimuli which are explained by features such as the functional gaps between networks and inadequate exclusion of networks.²

One limitation of the study is the systematic literature review design, with components such as sample sizes, effect sizes, and demographics not being weighted or controlled. Additionally, the lack of universal consensus of terminology given internet addiction was considered to be a limitation. The authors note that this is because multiple terms are used interchangeably, making it difficult to identify any similarities or differences between the terms.²

Further, the authors suggest that future research should include participants from a wider population to better describe how internet addiction can change how the brain controls behaviors and influence general well-being. They note that the implications of these findings can be significant to adolescent behavior, and that although the exact changes are not entirely clear, the observed changes in FC have the potential to influence several traits of adolescent development.^1,2

"Understanding how and where internet addiction affects the functional connectivity in the brains of adolescents as well as replicating fMRI studies with multiple populations can guide future global therapeutic and public health interventions," the authors noted in a news release.¹

References

1. Public Library of Science. Signaling between brain regions altered in teenage internet addiction. News release. June 4, 2024. Accessed June 5, 2024. https://www.eurekalert.org/news-releases/1046176

2. Chang, MLY, Lee, IO. Functional connectivity changes in the brain of adolescents with internet addiction: A systematic literature review of imaging studies. PLOS Mental Health 1(1): e0000022 doi:10.1371/journal.pmen.0000022