Effects of bilateral tDCS over DLPFC on response inhibition, craving, and brain functional connectivity in Internet gaming disorder: A randomized, double-blind, sham-controlled trial with fMRI
Abstract Background and aims Impaired inhibitory control accompanied by enhanced craving is hallmark of addiction. This study investigated the effects of transcranial direct current stimulation (tDCS) on response inhibition and craving in Internet gaming disorder (IGD). We examined the brain changes after tDCS and their correlation with clinical variables. Methods Twenty-four males with IGD were allocated randomly to an active or sham tDCS group, and data from 22 participants were included for analysis. Participants self-administered bilateral tDCS over the dorsolateral prefrontal cortex (DLPFC) for 10 sessions. Stop-signal tasks were conducted to measure response inhibition and participants were asked about their cravings for Internet gaming at baseline and post-tDCS. Functional magnetic resonance imaging data were collected at pre- and post-tDCS, and group differences in resting-state functional connectivity (rsFC) changes from the bilateral DLPFC and nucleus accumbens were examined. We explored the relationship between changes in the rsFC and behavioral variables in the active tDCS group. Results A significant group-by-time interaction was observed in response inhibition. After tDCS, only the active group showed a decrease in the stop-signal reaction time (SSRT). Although craving decreased, there were no significant group-by-time interactions or group main effects. The anterior cingulate cortex (ACC) showed group differences in post- versus pre-tDCS rsFC from the right DLPFC. The rsFC between the ACC and left middle frontal gyrus was negatively correlated with the SSRT. Discussion and conclusion Our study provides preliminary evidence that bilateral tDCS over the DLPFC improves inhibitory control and could serve as a therapeutic approach for IGD.
- Jeong, J.-E., Park, C., Kim, M., Cho, H., Pyeon, A., Jung, S., Jung, D., Kim, J.-Y., Choi, J., Chun, J.-W., Ahn, K.-J., & Kim, D.-J. (2024). Effects of bilateral tDCS over DLPFC on response inhibition, craving, and brain functional connectivity in Internet gaming disorder: A randomized, double-blind, sham-controlled trial with fMRI. Journal of Behavioral Addictions. https://doi.org/10.1556/2006.2024.00017
背景と目的
欲求の亢進を伴う抑制性制御の障害は、依存症の特徴である。本研究では、インターネットゲーム障害（IGD）における反応抑制と渇望に対する経頭蓋直流電流刺激（tDCS）の効果を検討した。tDCS後の脳の変化と臨床変数との相関を検討した。
方法
IGDの男性24名をtDCS群と偽群に無作為に割り付け、22名のデータを解析に用いた。参加者は、背外側前頭前野（DLPFC）に両側tDCSを10回自己投与した。反応抑制を測定するためにストップシグナルタスクが実施され、参加者はベースライン時とtDCS後にインターネットゲームへの欲求について質問された。機能的磁気共鳴画像データをtDCS前後に収集し、両側DLPFCと側坐核の安静時機能的結合（rsFC）変化における群間差を検討した。積極的tDCS群におけるrsFCの変化と行動変数との関連を検討した。
結果
反応抑制において有意な群間相互作用が観察された。tDCS後、SSRT（Stop-Signal Reaction Time）の減少がみられたのは活動群のみであった。渇望は減少したが、有意な群間相互作用や群間主効果は認められなかった。前帯状皮質（ACC）は、右DLPFCからのrsFCにおいて、tDCS後とtDCS前とで群間差を示した。ACCと左中前頭回間のrsFCは、SSRTと負の相関を示した。
考察と結論
本研究は、DLPFCに対する両側tDCSが抑制性制御を改善し、IGDの治療アプローチとなりうるという予備的証拠を提供する。