Is Neural Processing of Negative Stimuli Altered in Addiction Independent of Drug Effects? Findings From Drug-Naïve Youth with Internet Gaming Disorder

Abstract

Difficulties in emotion regulation are commonly reported among individuals with alcohol and drug addictions and contribute to the acquisition and maintenance of addictive behaviors. Alterations in neural processing of negative affective stimuli have further been demonstrated among individuals with addictions. However, it is unclear whether these alterations are a general feature of addictions or are a result of prolonged exposure to drugs of abuse. To test the hypothesis of altered negative affect processing independent of drug effects, this study assessed neural function among drug-naïve youth with a behavioral addiction-Internet gaming disorder (IGD). Fifty-six young adults (28 with IGD, 28 matched controls) participated in fMRI scanning during performance of a well-validated emotion regulation task. Between-group differences in neural activity during task performance were assessed using a whole-brain, mixed-effects ANOVA with correction for multiple comparisons at currently recommended thresholds (voxel-level p<0.001, pFWE<0.05). Compared to controls, youth with IGD exhibited significantly blunted neural responses within distributed subcortical and cortical regions including the striatum, insula, lateral prefrontal cortex and anterior cingulate in response to negative affective cues, as well as during emotion regulation. Independent component analysis (ICA) further identified between-group differences in engagement of a fronto-cingulo-parietal network, involving decreased engagement in IGD youth relative to controls. Study findings are largely consistent with those from prior neuroimaging studies in substance-use disorders, thus raising the possibility that neural processing of negative affect may be blunted across drug and behavioral addictions independent of acute or chronic drug effects.

Figures

Figure 1

Amygdala activity during emotion regulation task performance. Shows mean amygdala response (defined using anatomical masks from neuromorphometrics) during each task condition among healthy controls (HC) and individuals with Internet gaming disorder (IGD). Among HCs, amygdala responses were significantly increased while viewing negative images vs neutral images (p’s<0.001), however no differences in amygdala responses were found for the maintain vs regulate conditions (p>0.05). Among IGD participants, no significant differences in amygdala responses were observed across the different viewing conditions (p’s>0.05).

Figure 2

Whole-brain interaction between group (IGD/HC) and task condition (neutral/maintain/regulate). Shows significant group by condition interactions (whole-brain ANOVA; cluster-forming threshold p<0.001, pFWE<0.05; full results in Table 2) for IGD and HC participants during performance of an emotion regulation task. BOLD activity for selected clusters for each group across conditions are shown for reference.

Figure 3

Dorsal inhibitory control networks. Shows dorsal inhibitory control networks identified using independent component analysis. Repeated-measures ANOVAs further indicated a significant group by condition interaction (F(df=2)=4.85, p=0.018) on cingulo-parietal network (a) engagement, involving a pattern of decreased engagement during neutral vs maintain vs regulate among IGD participants, and relatively unchanged activity across conditions among HC participants. No significant group by condition interactions were found for engagement of dorsomedial (b) or dorsolateral (c) prefrontal networks (p’s>0.05).