Delay Discounting as a Biomarker for the Treatment of Gambling Disorder: a systematic review

Abstract

Aims: This systematic review aimed to assess whether delay discounting (DD) can be considered a dynamic biomarker in Gambling Disorder (GD) treatment by analyzing its potential changes in response to therapeutic interventions. Methods: A systematic review was conducted following PRISMA guidelines. Four databases (EBSCO, PubMed, Scopus, and Web of Science) were searched using predefined keywords related to DD, GD, and treatment outcomes. Eligibility criteria included observational and experimental studies that measured DD in individuals diagnosed with GD undergoing treatment or post-treatment. Results: The search yielded 241 articles, of which five met the inclusion criteria. These included four observational case-control studies and one randomized controlled trial (RCT). Observational studies consistently reported that DD remained elevated in Pathological Gamblers (PGs) undergoing treatment, with no significant differences across treatment stages. The RCT, assessing the effects of transcranial magnetic stimulation (TMS) on PG, found no significant changes in DD values compared to the sham group, despite some effects on gambling behavior. Comparisons with other addictive disorders showed that, unlike substance use disorders, where abstinence and treatment were associated with reduced DD, no such pattern was observed in GD. Conclusions: The findings suggest that while Delay Discounting is strongly associated with Gambling Disorder, it does not appear to be significantly influenced by treatment, unlike in substance use disorders. Longitudinal studies are needed to better understand possible changes in Delay Discounting in individuals with Gambling Disorder undergoing treatment.