White matter integrity of right frontostriatal circuit predicts internet addiction severity among internet gamers

Abstract

Excessive use of the internet, which is a typical scenario of self-control failure, could lead to potential consequences such as anxiety, depression, and diminished academic performance. However, the underlying neuropsychological mechanisms remain poorly understood. This study aims to investigate the structural basis of self-control and internet addiction. In a cohort of 96 internet gamers, we examined the relationships among grey matter volume and white matter integrity within the frontostriatal circuits and internet addiction severity, as well as self-control measures. The results showed a significant and negative correlation between dACC grey matter volume and internet addiction severity (p < 0.001), but not with self-control. Subsequent tractography from the dACC to the bilateral ventral striatum (VS) was conducted. The fractional anisotropy (FA) and radial diffusivity of dACC-right VS pathway was negatively (p = 0.011) and positively (p = 0.020) correlated with internet addiction severity, respectively, and the FA was also positively correlated with self-control (p = 0.036). These associations were not observed for the dACC-left VS pathway. Further mediation analysis demonstrated a significant complete mediation effect of self-control on the relationship between FA of the dACC-right VS pathway and internet addiction severity. Our findings suggest that the dACC-right VS pathway is a critical neural substrate for both internet addiction and self-control. Deficits in this pathway may lead to impaired self-regulation over internet usage, exacerbating the severity of internet addiction.

Keywords: DTI; VBM; dorsal anterior cingulate cortex; internet addiction; prefrontal‐striatum circuits; self‐control.

FIGURE 1

Analysis pipeline. Abbreviations: IAT, internet addiction test; SCS, self‐control score.

FIGURE 2

VBM results. (A) Multiple regression indicated the grey matter volume of dACC was negatively correlated with IAT scores after controlling for total intracranial volume, depression, anxiety scores and age as well as gender. (B) Partial correlation scatter plot of dACC grey matter volume and IAT, DSM scores. Abbreviations: GM, grey matter volume; dACC, dorsal anterior cingulate cortex; IAT, internet addiction test.

FIGURE 3

DTI results. (A) Bilateral dACC‐VS white matter pathways identified by tractography. (B) Correlations between white matter indexes of dACC‐rVS pathway and IAT, self‐control scores. (C) Correlations between white matter indexes of flipped dACC‐lVS pathway and IAT, self‐control scores. Abbreviations: rVS, right ventral striatum; lVS, left ventral striatum; dACC, dorsal anterior cingulate cortex; IAT, internet addiction test; SCS, self‐control score; FA, fractional anisotropy; RD, radial diffusivity.

FIGURE 4

Partial correlation between grey matter volume of dACC and DTI indexes. (A) Grey matter volume of dACC was positively and negatively correlated with FA and RD of dACC‐rVS pathway, respectively. (B) no significant correlation was found between grey matter volume of dACC and FA or RD of dACC‐lVS pathway. Abbreviations: GM, grey matter volume; dACC, dorsal anterior cingulate cortex; rVS, right ventral striatum; lVS, left ventral striatum; FA, fractional anisotropy; RD, radial diffusivity.

FIGURE 5

Results of mediation analysis. (A) Self‐control completely mediates the relationship between FA of dACC‐rVS pathway and internet addiction severity. (B) Appropriate entertainment subscale of self‐control completely mediates the relationship between FA of dACC‐rVS pathway and Excessive use subscale of internet addiction. (C) Appropriate entertainment subscale of self‐control completely mediates the relationship between FA of dACC‐rVS pathway and lack of control subscale of internet addiction. Abbreviations: SCS, self‐control score; IAT, internet addiction test; dACC, dorsal anterior cingulate cortex; rVS, right ventral striatum; FA, fractional anisotropy.