Background Internet Gaming Disorder (IGD) is officially listed as a behavioral addiction, exhibits high prevalence and has inadequate treatment efficacy. Targeting craving triggered by gaming cues represents a critical therapeutic objective. This study aimed to establish optimizing neuro-electrophysiologic biomarkers for IGD and develop a targeted neuromodulation protocol.

Methods In an exploratory study, we identified the optimized electroencephalography (EEG) indicators of IGD diagnose and craving through machine learning models based on event-related potential (ERP) during game cue exposure across two independent datasets (D1: 25 IGD, 22 Recreational Game Users (RGU), and 28 non-gaming Healthy Controls (HC); D2: 23 IGD and 23 HC). In an intervention study, we conducted a randomized, double-blind trial in 46 IGD participants, comparing active versus sham transcranial direct current stimulation (tDCS) targeting the optimized EEG marker. Active stimulation (1.5 mA, 20 min, 2 days) was applied during cue exposure (cathode: Pz; anode: right trapezius), while sham mimicked initial/final ramping without sustained current. The primary outcome was game craving (measured by QGU-B, VAS, and craving during exposure to presented/unpresented gaming cues) and daily gaming time, measured post-intervention and at 1 to 4 weeks follow-ups. The trial was registered at ClinicalTrials.gov (NCT06759051).

Findings Parieto-occipital P300 (with maximal discriminative power at central parietal (Pz), IGD>HC) during game reactivity emerged as optimized EEG indicators for IGD discrimination (accuracy > 80%), and were associated with craving. Then, Pz targeted cathodal tDCS synchronized with game cue exposure could significantly reduce craving (p < 0.001), gaming time (p < 0.001), and P300 alpha (p=0.048) after intervention and at 1 to 4 weeks follow-ups, with concomitant improvement of decision-making in the active group. Crucially, treatment effects could be generalized to novel gaming cues.

Conclusions These findings advance precision biomarkers and evidence-based neuromodulation strategies for IGD.

The authors have declared no competing interest.

NCT06759051

This work was supported in part by the STI2030 – Major Projects (2022ZD0211200).

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Peking University Institutional Review Board gave ethical approval for this work(IRB00001052-24146).

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