A neuroimaging-defined subtype had a substantially higher 2-year risk for developing internet gaming disorder than a lower-risk subtype, with conversion rates of 24% vs 7%, according to a longitudinal study published in BMC Medicine. The finding was replicated in an independent cohort (22% vs 4%).
Internet gaming disorder (IGD) is recognized in the International Classification of Diseases, 11th Revision, but early risk stratification remains limited. The findings suggest that impulsivity-linked brain connectivity patterns may help identify individuals at elevated risk before clinical onset.
The higher-risk subtype was characterized by an imbalance in brain connectivity associated with impulsivity and control. Compared with the lower-risk group, participants in the higher-risk subtype showed reduced orbitofrontal connectivity, linked to control processes, and increased occipital connectivity, which was positively associated with impulsivity. Key differences involved orbitofrontal-insula and precentral-occipital circuits.
Although the subtypes did not differ in IGD severity at baseline, participants in the higher-risk group had greater severity at follow-up. They also had higher baseline impulsivity, particularly in cognitive and nonplanning domains.
Baseline left orbitofrontal-left insula connectivity and right precentral-left lateral occipital connectivity each partially mediated the relationship between baseline impulsivity and IGD severity 2 years later, suggesting these circuits may partially link impulsivity to later disorder risk.
To derive these findings, researchers analyzed cross-sectional data from 770 participants across two data sets to identify resting-state functional connectivity (RSFC) features associated with impulsivity. They then evaluated the ability of those features to predict baseline IGD severity using separate training and testing data sets. In the longitudinal analysis, a discovery cohort of 220 participants and a replication cohort of 65 participants, all without IGD at baseline, were followed for 2 years.
Combining RSFC features that were positively and negatively associated with impulsivity improved prediction of baseline IGD severity compared with either feature set alone. Using these features, researchers applied a data-driven deep clustering approach (improved deep embedded clustering) to identify two neurobiological subtypes with distinct risk trajectories.
Clustering based on impulsivity scores alone or whole-brain connectivity alone did not distinguish subgroups with statistically significant differences in IGD outcomes, underscoring the value of integrating brain connectivity with behavioral measures.
The researchers noted several limitations, including modest longitudinal sample sizes, use of only 2 assessment time points, lack of detailed gaming behavior data, and no sex-specific analysis.
Taken together, the findings suggest that impulsivity-linked RSFC may support early identification of individuals at higher risk for IGD, although further validation is needed before clinical application. “Orbitofrontal–occipital connectivity imbalance may represent a candidate marker of IGD early identification and intervention,” wrote Xinwen Wen, of Xidian University in Xi'an, China, and colleagues.
The researchers reported no competing interests.
Source: BMC Medicine
