Effects and mechanism of High-Intensity transcranial Alternating Current Stimulation (HI-tACS) for social interaction and cravings in gaming disorder: a randomized controlled trial

Gaming disorder (GD) is characterized by impaired social function and heightened gaming cravings. Interpersonal brain synchronization (IBS) has been implicated in social interaction difficulties, but it remains unknown whether high-intensity transcranial alternating current stimulation (HI-tACS) can modulate IBS in GD. This study examined the gamma-frequency HI-tACS effects on gaming cravings and social interaction-related IBS in individuals with GD. In this randomized, double-blind, sham-controlled trial, 60 men with GD were recruited in Hunan, China. They were randomly assigned to an active HI-tACS group ( n = 30; 15 dyads) or a sham group ( n = 30; 15 dyads). Participants in the active group received 10 sessions of HI-tACS over 2 weeks, and those in the sham group received the sham intervention. Primary outcomes included gaming cravings and functional near-infrared spectroscopy-based IBS in competition and cooperation. The effects of the intervention were measured using linear mixed models. For gaming cravings, linear mixed models revealed a significant Time*Group interaction effect ( F (1, 52.5) = 4.95, p = 0.03), with no significant post-hoc results. IBS in competition showed significant interaction effects in the right temporoparietal junction ( F (1, 25) = 10.56, p = 0.04) and in the left ventrolateral prefrontal cortex ( F (1, 21.6) = 11.50, p = 0.03) at the single-channel level: after intervention, IBS decreased in the active group and increased in the sham group, respectively. Exploratory correlation analysis showed that the reduced IBS in the right temporoparietal junction was associated with the participants’ increased perceived social support. The current study identified changes in competition-task IBS following HI-tACS in individuals with GD. These findings offered initial neurophysiological evidence for further research to inform the potential therapeutic efficacy and underlying mechanisms of tACS in alleviating GD severity and restoring social function. The clinical trial was registered at ClinicalTrials.gov (NCT06208358) in 5th January 2024 as ‘A Study for the Disrupted Interpersonal Interaction Among Gaming Disorder Individuals and Treatment’.