Neural response to betel quid cues in chewers: a functional magnetic resonance imaging study

The World Health Organization regards betel quid (BQ) as a human carcinogen. The current study analyzes whether the BQ cues can elicit activity in the chewers’ craving-related brain areas. We adopted a cue-reactivity paradigm to examine the changes in the brain activities. The urge intensity was also included to examine whether it can moderate the brain areas stimulated by BQ cues. Sixteen male BQ chewers and 16 healthy male controls were recruited and analyzed. Four types of cues were adopted: BQ cues, matched food cues, visual control cues, and resting crosshair cued. The most direct and important comparison was between the brain activities elicited by the BQ cues versus those by the food cues. Furthermore, to test the current urge intensity effect, we compared BQ chewers with a strong urge versus those with a weak urge. All of the three-dimension anatomical and multi-slice task-based functional images were acquired using 3 T MRI. We found that (1) the BQ chewers and the healthy controls had similar brain activation patterns when comparing any two cue types, (2) the high-urge (not the low-urge) chewers showed craving-related activations (e.g., anterior cingulate cortex, medial orbitofrontal gyrus, and superior frontal gyrus) in the critical BQ cues vs. the food cue comparisons. (3) The high-urge chewers had larger contrast activations (BQ - Food) in many craving-related brain areas than low-urge chewers did (e.g., frontal gyrus). The urge states endorsed by the chewers can moderate the neural responses to BQ cues. Multisensory cues should be considered to elicit more intense and consistent cravings.