Attenuation of cue-induced smoking urges and brain reward activity in smokers treated successfully with bupropion

Twenty-two regular smokers (15+ cigarettes per day) were treated with bupropion and group therapy for 2 months. Subjects underwent positron emission tomography (PET) studies using measures of brain global and regional glucose metabolism (regional cerebral metabolic rates of glucose [rCMRglc]) with [18F]-Fluorodeoxyglucose (FDG) twice, after watching a videotape showing smoking scenes and after watching a control movie in counter-balanced order. A questionnaire of smoking urges (QSU) was filled in before and after watching both the movies. Changes in brain metabolic rates of FDG were analysed using Statistical Parametric Maps (SPM 2) in 11 smokers who abstained from smoking in comparison with 11 smokers who continued to smoke during the second month of treatment. Still-smokers had higher craving scores after watching the videotape showing smoking scenes compared with non-smokers. Second, watching the videotape showing smoking scenes compared with the control videotape in still-smokers resulted in increased metabolic rates in the striatum, thalamus and midbrain. Third, the ratings of the urge to smoke cigarettes while watching the videotape showing smoking scenes in still-smokers were associated with brain metabolic activity in the ventral striatum, anterior cingulate, orbitofrontal cortex, middle temporal lobe, hippocampus, insula, midbrain and thalamus. In conclusion, successfully treated smokers showed attenuated craving and reduced activity in the mesolimbic reward circuit.