Effects of Transcranial Direct Current Stimulation on Tobacco Withdrawal Symptoms
Condition: Nicotine Withdrawal; Tobacco Abstinence
MeSH terms: Substance Withdrawal Syndrome
Study type: Interventional
Phase: Phase 1

Summary: 
      We hypothesize that transcranial direct current stimulation will reduce tobacco withdrawal
      symptoms of tobacco dependent smokers abstinent from smoking for more than 10 hours.
    

Detailed description: 
      We will recruit 35 non-smokers and 30 adult smokers who smoke > 15 cigarettes/day for more
      than two years and are 18-55 years old. We expect about half of them will be females. All
      participants will be screened for drugs of abuse and female participants will receive a
      pregnancy test. Each smoker will participate in four tDCS sessions, one for sham and three
      for real tDCS, each for one set of electrode montage. The first set is dorsal lateral
      prefrontal cortex (i.e., F3 and F4 of 10/20 EEG system) and neck. The second set is middle
      line prefrontal cortex (Fz), superior parietal cortex (Pz), and bilateral inferior temporal
      cortex (T3 and T4). The third set is left dorsal lateral prefrontal cortex (F3) and superior
      parietal cortex (P1), and right inferior temporal cortex (T4). The sequence of real and sham
      tDCS will be counterbalanced among participants. Each session will last for 20 minutes and
      there will be a minimum 48 hours between the two sessions. Participants will be required to
      be abstinent from cigarette smoking overnight for a minimum of 10 hours and arrive at our lab
      around 8:30 AM for each tDCS session. After arrival, each participant will provide a breath
      sample for detection of any alcohol in their system, an assay of CO and for verification of
      abstinence from cigarette smoking. We will place a nicotine patch (Nicoderm with 21 mg
      nicotine) on the back of participants. We will also ask each participant to chew a nicotine
      gum (Nicorette gum with 4 mg nicotine) for 30 minutes. The participants will perform a
      battery of computerized tasks including the N-Back working memory task, and an attention task
      involving watching a computer screen and pressing buttons to indicate more odd or even
      numbers displayed on the screen. In addition participants will complete the following
      questionnaires related to mood, nicotine withdrawal, mental state, possible side effects, and
      cigarette craving: Profile of Mood States (McNair et al 1971), Shiffman-Jarvik Withdrawal
      Scales (Shiffman & Jarvik 1976), and Urge To Smoke (Jarvik et al 2000), tDCS side effects
      questionnaire, Wisconsin Smoking Withdrawal Scale (Welsch 1999), Perceived Stress Scale
      (Cohen 1983), Spielberger State/Trait Anxiety Questionnaire (Spielberger 1970).

      Each participant will repeat above battery of cognitive tasks and questionnaires after tDCS.
      Then they will be instructed to smoke one cigarette after this second battery of
      tasks/questionnaires, and repeat the second battery of questionnaires after cigarette
      smoking.
    

Intervention name(s): tDCS, prefrontal cortex and parietal cortex
Intervention type(s): Device
Intervention description(s): tDCS is a non invasive brain stimulation methods. We will use two anodes to stimulate prefrontal and/or parietal cortex using 2mA current for 20 minutes.
Other intervention name(s): transcranial direct current stimulation
Intervention model: Single Group Assignment
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: tDCS; brain stimulation; addiction; substance dependence; craving; cognition