Smoking-Related Cue-Induced Brain Activation in Adolescent Light Smokers

Abstract

To examine using functional magnetic resonance imaging whether adolescents with low levels of nicotine exposure (light smokers) display neural activation in areas shown to be involved with addiction in response to smoking-related stimuli. A total of 12 adolescent light smokers (aged 13-17, who smoked 1-5 cigarettes per day) and 12 nonsmokers (ages 13-17, never smoked a cigarette) from the San Francisco Bay Area underwent functional magnetic resonance imaging scanning. During scanning, the adolescents were shown photographic blocks of smoking and control cues. Smoking cues comprised pictures of individuals smoking cigarettes and smoking-related objects such as lighters and ashtrays. Neutral cues comprised images of everyday objects and individuals engaged in daily activities. For smokers, smoking cues elicited greater activation than neutral cues in the mesolimbic reward circuit (left anterior cingulate: t = 7.04, p < .001; right hippocampus: t = 6.37, p < .001). We found activation from smoking cues versus neutral cues within both the left and right frontal medial orbital regions (t = 5.09, p < .001 and t = 3.94, p = .001, respectively). Nonsmokers showed no significant difference in activation between smoking-related cues and neutral cues. Our finding that smoking cues produced activation in adolescent light smokers in brain regions, similar to that seen in adult and teenage heavy smokers, suggests that adolescents exhibit heightened reactivity to smoking cues even at low levels of smoking. This article adds to the existing published data by suggesting that nicotine dependence may begin with exposure to low levels of nicotine, thus underscoring the need for early intervention among adolescent smokers.