The Neural Mechanisms Of Reducing Smoking Cravings Via Hypnotic Aversion Suggestions

Smoking craving is a key contributor of substance dependency,and mind-body therapies such as hypnosis,meditation and mindfulness have been used to help smoking cessation and reduce smoking relapse rates,but its neural basis is poorly understood,which hinders its clinical application.The present study investigated the neural mechanism of hypnotherapy on smoking craving,especially,whether the hypnosis involves a top-down or bottom-up mechanism.In the first experiment,two groups of 45 smokers with high hypnotic sensitivity,who were screened from volunteers with Stanford Hypnotic Susceptibility Scale,underwent a smoking aversion suggestion and performed a smoking-related cue task.One group of smokers(24 smokers)underwent fMRI scanning twice(normal and hypnotic states),whereas the other group(21 smokers)underwent two EEG sessions and performed a similar task.There was no significant difference in gender,age,number of cigarettes smoked per day or number of years smoked between two groups.The Tobacco Craving Questionnaire(TCQ)was used to test smoking craving levels.The participants used a visual analog scale to assess the distaste they experienced when viewing smoking-related pictures.The fMRI group was examined for nicotine dependence using the Fagerstrom Test for Nicotine Dependence(FTND)at 1-week,1-month,and 3-month follow ups.The results showed that both groups exhibited the self-reported cravings of smokers decreased significantly,whereas the subjective experience of aversion to smoking increased significantly following hypnosis.Smoking cue-elicited activations in right dorsal lateral prefrontal cortex(rDLPFC)and left insula(lI),as well as the functional connectivity of these two brain regions,were significantly increased during hypnotic state compared to normal state.The EEG source reconstruction indicated that the rDLPFC activations anteceded the activation of the left insula.Further,the level of nicotine dependence at 1-week follow-up in the fMRI group significantly lower than that before hypnosis,and was positively correlated with the activations in the rDLPFC in the hypnotic state.These results suggest that the reduction in smoking craving after hypnotic aversive suggestion may be due to the top-down regulation of the rDLPFC and the left insula.Our findings provide novel neurobiological evidence for understanding the treatment effects of hypnosis on nicotine dependence,and the prefrontal-insula circuit may serve as an imaging biomarker to monitor the treatment efficacy noninvasively.In the second experiment,we used resting state EEG coherence to explore the underlying neural mechanism of hypnosis treatment for nicotine dependence.The sample consisted of 42 male smokers participated in this study.The 8-minute resting state EEG in the normal state and 8-minute resting state EEG after hypnotic induction in the hypnotic state was recorded.The hypnotist subsequently issued the smoking disgust suggestion to the participants in the hypnotic state.Tobacco Craving Questionnaire was completed by every participant.The results showed that the EEG coherence in delta band frequency and theta band frequency significantly increased,and the EEG coherence in alpha band frequency and beta band frequency significantly decreased between the normal state and the hypnotic state,which may suggest alterations in consciousness because of hypnotic induction.It is of interest to note that the delta coherence at the resting state in the normal state between the right frontal region and the left posterior region may predict smoking craving reduction after hypnotic aversion suggestions.These results showed that the functional connectivity between the right frontal region and the left posterior region plays a significant role in reducing smoking cravings by hypnotic aversion suggestions.Therefore,these brain regions might be regarded as a useful target to treat nicotine dependence.The neural mechanisms identified in this study are important for the design and optimization of hypnotherapy programs for nicotine addiction and other psychiatric disorders as well as for predicting and monitoring treatment outcomes.This finding will help us to explore other mechanisms of psychosomatic research in future studies,whether these treatments are top-down or bottom-up processing still unknown.