A role for the right dorsolateral prefrontal cortex in enhancing regulation of both craving and negative emotions in internet gaming disorder: A randomized trial

•Internet gaming disorder (IGD) has few empirically validated treatments.•tDCS of the right dlPFC enhanced craving- and negative-emotion-regulation in IGD.•Common substrates underlie reward- and negative-emotion-regulation in IGD.•tDCS may be a promising approach for treating IGD. Reward-seeking and relief from negative emotions are two central motivational drives underlying addictions. Impaired executive control over craving and negative emotions contributes to compulsive addictive behaviors. Neuroimaging evidence has implicated the prefrontal cortex (PFC) in regulating craving or emotions. This study aims at examining whether anodal transcranial direct current stimulation (tDCS) over a specific region of the PFC would enhance both regulation processes. Thirty-three men with internet gaming disorder received active (1.5 mA for 20 minutes) and sham tDCS over the right dorsolateral PFC (dlPFC) one week apart in a randomized order. During each stimulation session, participants regulated craving for gaming during a regulation of craving (ROC) task and negative emotions during an emotion regulation (ER) task using cognitive reappraisal. Subjective ratings of craving and negative emotions and skin conductance responses (SCRs) were recorded. For both craving and negative emotions, tDCS of the right dlPFC facilitated downregulation and upregulation: active relative to sham tDCS decreased ratings (ROC: 95% CI of difference -1.38 to -0.56, p < 0.001; ER: -1.65 to -0.70, p < 0.001) and/or SCRs (ROC: -1.99 to -0.41 μs, p = 0.004) for downregulation, and increased ratings (ROC: 0.24 to 0.82, p = 0.001; ER: 0.26 to 0.72, p < 0.001) for upregulation. These findings provide the first experimental evidence confirming that tDCS of the right dlPFC enhances both craving- and negative-emotion-regulation. This suggests a promising approach for concurrently enhancing executive control over two central motivational drives underlying addictions.