The goal of this study is to determine whether transcranial magnetic stimulation (TMS) is an effective treatment in decreasing craving in individuals who habitually smoke cigarettes. The study consists of six total visits to MUSC; one for the consent process, two that will include MRI scans, and five that will include TMS administration. Compensation will be provided for each visit.
Nicotine dependence remains a significant public health concern. Nicotine can affect brain neural oscillations. A magnetic field applied to the outside of the skull can produce electrical activity in the brain without significant pain or the need for anesthesia. In this proposal, we will build an individual brain signal-driven transcranial magnetic stimulation loop, and then test whether this stimulation loop can modulate neural oscillations and reduce cue-induced craving, including nicotine craving. This research will build an innovative brain stimulation method for neuroscientific research and develop a potential efficacy therapy for nicotine dependence as well other neuropsychiatric disorders.
This research is being conducted at the Medical University of South Carolina Institute of Psychiatry Brain Stimulation Lab by Dr. Mark George to see if deep repetitive transcranial magnetic stimulation (dTMS) is effective in assisting participants to quit smoking. TMS is a noninvasive medical procedure that uses magnetic fields to stimulate nerve cells in the brain to act as an aid to smoking cessation. The treatment period will involve 18 active/sham treatments to be given daily for 3 weeks then weekly treatments in week 4, 5, and 6. A follow up visit will be scheduled about 2 1/2 months after week 6. The entire study is four months in duration. Participants who may be recruited into the study would include the following: men and women 22-70 years of age, chronic; heavy smokers who have smoked for more than 1 year, with no period of abstinence greater than 3 months during the past year; subjects who are motivated to quit smoking; subjects who have negative answers on the TASS; and those who are able to sign an informed consent.
Cigarette smoking causes significant morbidity and mortality in the United States. Smoking cessation is difficult, with the average smoker attempting to quit five times before permanent success. Moreover, the majority of smoking quit attempts result in relapse. Brain stimulation for smoke cessation is an exciting new area that builds on advancing neuroscience knowledge concerning the functional neurocircuitry of addiction. Cortical stimulation can now be performed non-invasively by transcranial magnetic stimulation (TMS). Several studies have shown that TMS can reduce cue-elicited craving in smokers. Previous research by our group has shown that a single session of 15 minutes high frequency (10 Hz) repetitive TMS (rTMS) at 100% motor threshold over the left dorsal lateral prefrontal cortex (DLPFC) can reduce cue-induced craving compared to sham TMS. However, the mechanism by which craving is reduced by rTMS is poorly understood both at behavioral and neural levels. Neuroimaging studies in nicotine dependence have revealed cue-related responses in numerous brain areas, including frontal, parietal cortices and subcortical areas. Recently functional magnetic resonance imaging (fMRI) studies by our group have shown that cue-induced craving induced brain activation in ventral medial prefrontal cortex (VMPFC), including medial frontal, orbital frontal and anterior cingulate. This Chair Research Development Fund (CRDF) pilot proposal will integrate two new techniques- TMS and fMRI to investigate DLPFC-VMPFC pathway in smokers. Using double-masked methods we hypothesize that cue-induced exposure will induce brain activity in VMPFC, and 15 minutes rTMS over DLPFC will reduce cue-induced craving through modulating DLPFC-VMPFC pathway (increased activity DLPFC and decreased activity VMPFC). In the one year of project, we plan to recruit 10 non-treatment-seeking nicotine-dependent cigarette smokers and 20 non-smoking participants, both males and females of all ethnic and racial groups between the ages of 18 and 60 to participate in the study. The participants will randomly receive two different types of brain stimulation: active rTMS or sham rTMS over the left DLPFC with a 1 week interval between treatments. MRI scans will be completed pre and post rTMS. The data from this pilot will provide the information needed for submitting a larger-scale investigation (R01) to investigate cue craving neutral pathway and develop a potential clinical applications of TMS in smoke cessation.
Cigarette smoking is the leading preventable cause of death and disability in the U.S. and individuals with elevated depression symptoms or clinically diagnosed major depressive disorder (MDD) smoke at significantly higher rates than non-depressed individuals. Elevated negative affect and affective dysregulated emotional control may contribute to greater smoking among individuals with MDD. The proposed research will shed new light on the neural mechanisms that govern associations between depression and smoking. Despite known and costly associations between these factors, little is known regarding their co-occurrence and such information will provide a foundation for the development of novel and more effective interventions. We are recruiting adult smokers and nonsmokers, and individuals with or without depression, ages 18 and older to participate.