Background: Despite the association of Gambling Disorder (GD) with poor mental health, treatment options generally lack components targeting emotional difficulties. This study investigated the feasibility and acceptability of adding strategies of emotion regulation to an eight-session weekly group treatment.

Method: This non-randomized pilot study recruited 21 treatment-seeking adults with GD, (mean age = 36.3, 19% females) from addiction care. In a mixed methods design, measures of within-group changes in self-reported symptoms of GD were complemented with thematic analysis of post-treatment interviews regarding the feasibility of the treatment.

Results: Within-group scores on the Gambling Symptoms Assessment Scale (G-SAS) showed a 47% decrease (β: -0.1599, 95% CI: − 0.2526 to − 0.0500) from pre-treatment to 12-month follow-up, with Hedges’ g = 1.07 (CI: 0.57–1.60).

The number of GD-symptoms according to the Structured Clinical Interview for Gambling Disorder (SCI-GD) decreased from 7.0 (SD = 1.60) at pre-treatment to 2.1 (SD = 2.36) at 12-month follow-up. Participants completed an average of 6.3 sessions and rated the intervention high in satisfaction and acceptability. Feasibility interviews showed no noticeable negative effects or ethical issues. Furthermore, helpful components in the treatment were: increased awareness of emotional processes and strategies to deal with difficult emotions.

Conclusions: Adding emotion regulation strategies in the treatment of GD is feasible and acceptable and warrants further investigation in a controlled trial.

Trial registration: This study was registered with ClinicalTrials.gov (Identifier NCT03725735).