Background and AimsGambling disorder is characterized by poor regulation of negative emotions and impulsive behaviours. This study aimed to (1) compare gambling disorder patients (GDPs) and healthy controls (HCs) in self-report and brain activation measures of emotion regulation; and (2) establish its relationship with negative emotion-driven impulsivity. DesignTwo cross-sectional case-control studies including GDPs and HCs. Setting and ParticipantsGDPs and HCs were recruited from specialized gambling clinics in Andalusia (Spain), where they were following out-patient treatment, and from the community, respectively. Study 1 included 41 GDPs and 45 HCs [All males; M-age=35.22, 33.22; standard deviation (SD)=11.16, 8.18; respectively]. Study 2 included 17 GDPs and 21 HCs (16/20 males; M-age=32.94, 31.00; SD=7.77, 4.60; respectively). MeasurementsIn study 1, we compared both groups on suppression and re-appraisal emotion regulation strategies [Emotion Regulation Questionnaire (ERQ)]. In study 2, we compared GDPs with HCs on brain activation associated with down-regulation of negative emotions in a cognitive re-appraisal task, measured with functional magnetic resonance imaging (fMRI). In both studies, we correlated the measures of emotion regulation with mood-related impulsivity indicated by negative urgency (UPPS-P impulsive behaviour scale). FindingsGDPs relative to HCs showed higher levels of emotional suppression [F=4.525; P=0.036; means difference M-HCs-M-GDPs=-2.433, 95% confidence interval (CI)=-4.706, -0.159] and higher activation of the premotor cortex and middle frontal gyrus during negative emotion regulation in the fMRI task [P0.005, cluster size (CS)>50 voxels]. Negative urgency correlated positively with emotional suppression (r=0.399, 95% CI=0.104, 0.629, one-tailed P=0.005) and middle frontal gyrus activation during negative emotion regulation (P0.005, CS>50) in GDPs. ConclusionsGambling disorder is associated with greater use of emotional suppression and stronger pre-motor cortex and middle frontal gyrus activation for regulating negative emotions, compared with healthy controls. Emotional suppression use and middle frontal gyrus activation during negative emotion regulation are linked with negative emotion-driven impulsivity in this disorder.