Lower Ventral Striatal Activation During Reward Anticipation in Adolescent Smokers

Abstract

Adolescents are particularly vulnerable to addiction, and in the case of smoking, this often leads to long-lasting nicotine dependence. The authors investigated a possible neural mechanism underlying this vulnerability. Functional MRI was performed during reward anticipation in 43 adolescent smokers and 43 subjects matched on age, gender, and IQ. The authors also assessed group differences in novelty seeking, impulsivity, and reward delay discounting. In relation to the comparison subjects, the adolescent smokers showed greater reward delay discounting and higher scores for novelty seeking. Neural responses in the ventral striatum during reward anticipation were significantly lower in the smokers than in the comparison subjects, and in the smokers this response was correlated with smoking frequency. Notably, the lower response to reward anticipation in the ventral striatum was also observed in smokers (N=14) who had smoked on fewer than 10 occasions. The present findings suggest that a lower response to reward anticipation in the ventral striatum may be a vulnerability factor for the development of early nicotine use.