Enhancing Relapse Prevention for Smoking Cessation With Repetitive Transcranial Magnetic Stimulation
Condition: Smoking Cessation
MeSH terms: Recurrence
Study type: Interventional

Summary: 
      Tobacco use is one of the most significant cancer control and public health challenges in the
      US today. Half of all smokers in the US will attempt to quit tobacco each year, but fully 95%
      of those who attempt to quit will reverse this decision within 12 months and choose the
      transient, albeit immediately rewarding activity of smoking at the cost of much larger
      long-term rewards such as future health and long life. This project seeks to improve
      scientific knowledge of these decision-making processes and potentially improve the treatment
      of tobacco dependence by examining the feasibility of using a brain stimulation technique,
      repetitive Transcranial Magnetic Stimulation or rTMS to improve the efficacy of an existing
      evidence-based relapse prevention intervention. rTMS is an FDA-cleared treatment for
      medication resistant depression and is being examined as a treatment for a variety of other
      disorders. This study will utilize an intensity and duration of rTMS that is well within the
      safety parameters and similar in location and intensity to that used in previous studies with
      smokers to reduce cigarette consumption.
    

Detailed description: 
      This project seeks to improve scientific knowledge of the decision-making processes of
      smokers and improve tobacco dependence treatments. The dorsolateral prefrontal cortex (DLPFC)
      influences decision-making by integrating inhibitory mechanisms with emotionally charged
      information from limbic regions, thereby exerting an inhibitory influence on seductive,
      immediately rewarding options with long-term costs, such as smoking. Delay discounting is the
      degree to which one de-values delayed outcomes, such as future health and long life.
      Converging evidence indicates that choosing a delayed option with a larger reward is
      associated with increased activity in the DLPFC. This study proposes that choosing to smoke
      after making a decision to quit reflects a situation where the DLPFC is insufficiently
      activated to exert an inhibitory influence on the immediately rewarding option of smoking.

      Preliminary studies indicate that stimulation of the DLPFC with 20 Hz high frequency
      repetitive Transcranial Magnetic Stimulation (rTMS) reduces delay discounting (i.e., causes
      individuals to choose delayed, higher value options); reduces cigarette consumption in
      smokers intending to quit; improves executive function, learning, memory, and attention; is a
      promising adjunct to cognitive-behavioral treatment of other disorders; and is likely to
      improve the efficacy of existing cognitive-behavioral treatments for tobacco dependence.

      The goal of this study is to make an informed recommendation, based on measures of
      feasibility, of whether or not this intervention should be tested for efficacy. A double
      blind, randomized between-subjects treatment (active or sham) design will be employed in
      which all subjects are exposed to the same relapse prevention materials during rTMS
      stimulation.

      Aim 1: Examine the feasibility of combining high frequency rTMS with an evidence-based,
      self-help, cognitive-behavioral relapse prevention intervention using multiple feasibility
      indicators (demand, acceptability, practicality, limited-efficacy testing, and adequate
      blinding).

      Aim 2: Examine differences in delay discounting between the active and the sham conditions 2,
      4, 8, and 12 weeks after the quit day.

      Aim 3: Use latency to relapse comparisons to calculate estimates of the effect size of this
      intervention on abstinence.
    

Intervention name(s): rTMS Active 20Hz; rTMS Sham
Intervention type(s): Device; Device
Intervention description(s): Active stimulation will be delivered with 70mm Double Air Film Coils. Participants will attend eight 20Hz sessions within two weeks of the scheduled quit date. Participants will receive 20Hz at 110% of the MT for 1 second, less than the limits indicated in the guidelines. These stimulation parameters have been utilized with no serious adverse events in previous studies to decrease delay discounting among smokers and non-smokers. These parameters are similar to or less intense than those utilized in other smoking cessation studies. All participants will receive rTMS over the same area of the DLPFC (6cm anterior to the MT area) while reading relapse prevention booklets supervised by the study coordinator.; The sham stimulation uses a similar 70mm Double Air Film Coil to look and sound like the active coil, but the magnetic field produced by the sham coil is markedly attenuated (only 5% of stimulator output setting: that is 2.25% of the maximum stimulator output (5% of 45% = 2.25%) and biologically inactive. Participants in this condition will attend eight sham sessions within two weeks of their scheduled quit date. During these sessions, they will also read relapse prevention booklets supervised by the study coordinator. The sham coil is not intended to and does not produce a stimulation effect so there is no proposed biologic mechanism of action.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: smoking cessation; tobacco use disorder; delay discounting; repetitive transcranial magnetic stimulation; relapse prevention