Probability Distortion in the relationship between Depression and Problem Gambling: A Mediation Analysis

Abstract: We posit that people with depressive symptoms are prone to problem gambling, and explore whether one possible driver of this is that depression increases misperception of probabilities. To test this hypothesis, we conducted a self-report survey on 230 regular gamblers recruited from Prolific. Depression was measured by the Major Depression Inventory (MDI), and problem gambling gambling was assessed by the South Oaks Gambling Screen: Revised for Adolescents (SOGS-RA). Perception of probabilities was elicited from 15 prospects with non-negative payo↵s. Two central theoretical framework used in this study are mediation analysis and probability weighting function. Three main findings of the study are (i) probability distortion is not the mediator between depression and problem gambling, as there is no linear relationship between depression and probability distortion, (ii) in comparison to gamblers with no problem gambling, pathological gamblers overweight small probabilities more and underweight big probabilities to a lesser extent, and (iii) from an exploratory analysis, a depressive state has a quadratic e↵ect on how individuals perceive big probabilities.