Grant: Project Grant

In addicted people, exposure to things like drug paraphernalia (known as contextual cues) is believed to trigger cravings, drug use and relapse. Exactly how cues promote such outcomes remains poorly understood. One possibility is that cues influence decision-making and tip the scales in favor of the maladaptive addictive behaviour, making it seem more appealing and worthwhile. Our work in both rats and humans suggests that adding sensory reward cues - similar to the lights and sounds in gambling settings - results in riskier and more disadvantageous choice on gambling-like task. In rats, these effects of cues are dependent on the neurotransmitter dopamine. Our goals are: 1) to study whether problem gamblers are particularly susceptible to risk-promoting effects of sensory reward cues - which are abundant in gambling settings; 2) investigate whether dopamine contributes to cue-driven risky choice in healthy humans and problem gamblers, and dopamine system's responsiveness to cues might be associated with problem gambling. To address these aims, we will use positron emission tomography to look at dopamine levels during decision-making in the presence versus in the absence of sensory reward cues. We will do this in a group of healthy participants and a group of problem gamblers. We expect to find that decisions of problem gamblers will be more influenced by cues than those of healthy participants. We also expect that the presence of cues will result in greater elevation in dopamine levels for problem gamblers than healthy controls.