Changing Thought and Action in Tobacco Dependence With Transcranial Magnetic Stimulation

Tobacco use is the greatest cause of preventable death in the US and cigarette smokers exhibit substantial relapse following treatment. Understanding the brain mechanisms involved in tobacco dependence is an important step toward reducing the high rate of relapse associated with current behavioral and pharmacological treatments for smoking cessation. This study seeks to examine the effects of high frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on decision-making and smoking behavior. A concept central to this study is that "quitting" tobacco necessitates making conscious choices not to smoke (to delay gratification) and these choices are influenced by the balance of activity between the frontal-parietal systems that process the value of rewards and limbic systems that are involved with immediate gratification. We aim to: 1) determine how two different levels of cortical excitation (10 Hz and 20Hz), induced by different rTMS frequencies, influence reward and risk-taking choices and cigarette consumption. Additionally, we aim to 2) determine how limbic activation due to acute nicotine withdrawal and/or satiation modifies the effects in aim 1. Twenty non-smoking and 20 smoking participants will receive two levels of high frequency rTMS and comparable sham stimulation (using electrical scalp stimulation) delivered over the left prefrontal cortex. Smokers will also crossover between nicotine satiation and acute withdrawal conditions to determine how rTMS interacts with limbic activation associated with nicotine use and withdrawal. In addition, changes in preattentional (brainstem-thalamus processing as measured using the P50 midlatency auditory evoked potential) and attentional (thalamocortical processing as measured using the Psychomotor Vigilance Task; PVT) will be assessed before and after treatment to quantitatively determine changes in preattentional/arousal and attentional function.

Inclusion criteria

• Age 19-55
• Must speak English
• Must be right handed
• Must pass the Transcranial Magnetic Stimulation Adult Safety and Screening Questionnaire (TAAS)
• Smoking participants must be highly dependent with a score of 6 or greater on the Fagerstrom Test for Nicotine Dependence

Exclusion criteria

• Positive test for drugs of abuse
• Positive pregnancy test
• A personal or family history of epilepsy
• A history of anticonvulsant medication use
• A personal history of head injury
• A history of aneurysm, stroke, or previous cranial neurosurgery
• A diagnosis of bipolar disorder
• A neurological or psychiatric disorder for which hospitalization was required
• Tinnitus
• Metal implants in the head, neck or cochlea
• A pacemaker
• Migraines
• A history of taking medications that lower seizure threshold (i.e. such as tricyclic antidepressants or bupropion)
• Claustrophobia (due to the MRI)
• Used any form of tobacco in the past two years if they desire to be a non-smoking participant
• Plans to quit smoking in the next 30 days if they desire to be a smoking participant
• Current use of any medications for tobacco cessation (i.e. nicotine replacement, bupropion, varenicline, etc.)
• A report of a high motivation to quit smoking (score 7 or great on the Motivation scale)