Debiasing Strategies for Problem Gambling: Using Decision Science to Inform Clinical Interventions

House-edge information and a volatility warning lead to reduced gambling expenditure: Potential improvements to return-to-player percentages

Cost-of-play information is one public health intervention recommended to help reduce gambling-related harm. In the UK, this information is given on electronic gambling machines in a format known as the "return-to-player", e.g., "This game has an average percentage payout of 90%." However, previous evidence suggests that this information could be improved by equivalently restating it in terms of the "house-edge", e.g., "This game keeps 10% of all money bet on average." A "volatility warning," stating that this information applies only in the statistical long-run, has also been recommended to help gamblers understand cost-of-play information. However, there is no evidence comparing these information provisions' effect on gamblers' behavior. An experiment tested US gamblers'(N = 2433) incentivized behavior in an online slot machine, where this information was manipulated between-participants along with a counter showing the total amount bet. Preregistered analyses showed that participants gambled significantly less when house-edge information or a volatility warning were shown compared to standard return-to-player information, with no effect of the total amount bet counter, and no significant interaction effects. However, these significant findings had small effect sizes, suggesting that a public health approach to gambling should not rely on informational provisions only. Subject to supportive evidence from more ecologically-valid designs such as field studies, these results suggest that improved cost-of-play information could lead to reduced rates of gambling expenditure and therefore benefit a public health approach to gambling.

Dopaminergic signaling of uncertainty and the aetiology of gambling addiction

Although there is increasing clinical recognition of behavioral addictions, of which gambling disorder is the prototype example, there is a limited understanding of the psychological properties of (non-substance-related) behaviors that enable them to become 'addictive' in a way that is comparable to drugs of abuse. According to an influential application of reinforcement learning to substance addictions, the direct effects of drugs to release dopamine can create a perpetual escalation of incentive salience. This article focusses on reward uncertainty, which is proposed to be the core feature of gambling that creates the capacity for addiction. We describe the neuro-dynamics of the dopamine response to uncertainty that may allow a similar escalation of incentive salience, and its relevance to behavioral addictions. We review translational evidence from both preclinical animal models and human clinical research, including studies in people with gambling disorder. Further, we describe the evidence for 1) the effects of the omission of expected reward as a stressor and to promote sensitization, 2) the effect of the resolution of reward uncertainty as a source of value, 3) structural characteristics of modern Electronic Gaming Machines (EGMs) in leveraging these mechanisms, 4) analogies to the aberrant salience hypothesis of psychosis for creating and maintaining gambling-related cognitive distortions. This neurobiologically-inspired model has implications for harm profiling of other putative behavioral addictions, as well as offering avenues for enhancing neurological, pharmacological and psychological treatments for gambling disorder, and harm reduction strategies for EGM design.