Problem Gambling and its Relation to Delayed Reward Discounting: A Secondary Analysis of a Randomized Controlled Trial

Delayed reward discounting (DRD) refers to the phenomenon where future rewards are perceived as less valuable compared to immediate rewards. The extent of this devaluation has been repeatedly linked to addictive behaviors. DRD could play an important role in the development and maintenance of problem gambling. We aim to better understand the relationship between DRD and problem gambling, examine temporal changes in DRD, and evaluate its predictive value for adherence. We conducted a secondary analysis of data from participants in the Win Back Control study (n = 345), a two-arm RCT that demonstrated effectiveness in reducing problematic gambling behavior. DRD was assessed using the Monetary Choice Questionnaire (MCQ), the severity of problem gambling was measured with the Problem Gambling Severity Index (PGSI), and gambling symptom severity was evaluated using the Gambling Symptom Assessment Scale (G-SAS). DRD is significantly positively associated with gambling symptom severity (G-SAS: b = 13.90, p = 0.002) and problem gambling severity (PGSI: b = 9.39, p < 0.001). DRD decreased significantly on a weekly basis over the three measurement time points (b = -0.001, p < 0.001). DRD could not be identified as a mediator, which should be further investigated in future studies. DRD is significantly positively associated with problem gambling severity and gambling symptom severity. DRD does not serve as a predictor of adherence. DRD decreases over the three time points along with severities of gambling behavior and gambling symptoms. However, the findings are correlational and may be affected by attrition bias.