The Role of Dopamine in Cue-induced Craving: A [11C]-(+)-PHNO PET Study in Tobacco-dependent Smokers

Environmental stimuli associated with drug use are related to drug craving and relapse. The mechanism of cue-induced craving is thought to involve the release of dopamine (DA) in brain regions associated with reward and habit formation. The aim of the study was to investigate the role of DA in cue-induced craving in tobacco-dependent smokers using Positron Emission Tomography (PET) and a picture cue paradigm. Tobacco-associated cues were capable of eliciting significantly greater subjective reports of craving relative to neutral cues in tobacco smokers (n=6) in a neuroimaging environment. Using this cue paradigm and [11C]-(+)-PHNO PET (n=6), a non-significant trend towards a greater decrease in binding potential, indicative of dopamine release, was shown in selected brain regions of interest. These findings are similar to findings in cocaine-dependent individuals and suggest the involvement of dopamine in the response to smoking-associated cues in tobacco-dependent individuals.MAS