Animal models of gambling-related behaviour

Abstract

Gambling is a heterogeneous and complex disorder that is phenomenologically similar to drug or alcohol addiction. The range of gambling games continues to proliferate, and the ease of access to gambling opportunities continues to increase. However, there are currently no dedicated pharmacological treatments available for gambling disorder (GD), and the understanding of the neurobiological mechanisms underlying GD is limited. Consequently, GD is increasingly recognised as a significant public health concern. Animal models may facilitate a better understanding of the neurobiological basis of GD. However, gambling is a heterogeneous disorder and may perhaps be better understood by animal paradigms aimed at modeling singular domains of dysfunction observed within human gamblers. These domains include excessive cognitive biases or beliefs, increased impulsivity, deficits in cost-benefit decision-making and augmented cue reactivity. Thus, deficits within one of these core areas could be argued to represent a precipitating vulnerability towards the development of GD. Ergo animal models that can parametrise similar deficits could be used to elucidate the neural and neurochemical systems contributing to these perturbations and may be of considerable benefit in clarifying the pathogenesis of GD. Moreover, such information could be useful in aiding the development of novel pharmacotherapies. Here, we discuss examples of animal research in each of these core domains. Initially we present data from the rodent slot machine task that suggests rats, like humans, are susceptible to the near-miss effect, a potent cognitive distortion that has been linked to the severity of GD. Secondly, we discuss several behavioural tasks designed to capture different aspects of impulsivity in rodents. We then consider tasks that measure distorted or nonoptimal decision-making, before reviewing tasks that measure augmented cue reactivity.