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

Abstract

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.

Keywords: Craving regulation; Internet gaming disorder; Negative emotion regulation; Transcranial direct current stimulation.

Figure 1.

Structure for the ROC and ER blocks. Each block began with a down- or upregulation cue which was followed by four pictures (gaming pictures in the ROC task or negative pictures in the ER task). Participants were instructed to view and reappraise pictures in accordance with the regulation condition of the current block. After each picture, participants rated how much they craved playing internet games in the ROC blocks and rated how negative they felt in the ER blocks.

Figure 2.

tDCS effects on regulation of craving and negative emotions. (A) For downregulation, decreased craving was observed during active vs. sham stimulation; for upregulation, increased craving was observed during active vs. sham stimulation. (B) For downregulation, decreased SCRs were observed during active vs. sham stimulation during performance of the ROC task. (C) For downregulation, decreased negative emotional responses were observed during active vs. sham stimulation; for upregulation, increased negative emotional responses were observed during active vs. sham stimulation. (*p < 0.05, **p < 0.01, and ***p < 0.001; n.s, not significant)