Association between internet addiction, brain structure, and social capital in adolescents

ABSTRACTOf late, internet addiction among adolescents has become a serious problem, with increased internet use. Previous research suggests that the more people become addicted to the internet, the more they isolate themselves from society. Conversely, it has been suggested that abundant social capital (the networks of relationships among people who live and work in a particular society) protects people from becoming addicted to the internet. This study focused on the brain structure of typical adolescents (10–18 years of age) and hypothesized that the size of the left dorsolateral prefrontal cortex (DLPFC), which is thought to be associated with self-control ability, is associated with both internet addiction and social capital. Voxel-based morphometry analysis indicated that left DLPFC volume was negatively correlated with the severity of internet addiction and positively correlated with social capital. Furthermore, correlation analysis demonstrated that the severity of internet addiction and social capital were negatively correlated. The statistical association between them was no longer significant when left DLPFC volume was used as a control variable. These results suggest that the left DLPFC may mediate the relationship between social capital and internet addiction in adolescents.KEYWORDS: Adolescentvoxel-based morphometryinternet addictionsocial capitaldorsolateral prefrontal cortex AcknowledgementsWe thank Tetsuya Matsuda, Junko Yamada, Qiulu Shou, Takuji Kinjo, and Mika Ohsawa for their help in conducting this research. We would also like to thank Editage (www.editage.com) for the English language editing.Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis study was supported by the Japan Society for the Promotion of Science, KAKENHI, Grant Number JP19K03197. AMED supported this research under Grant Number JP18dm0307001.