In this pilot study, the feasibility of using tDCS (a non-invasive brain stimulation technique) while performing a task requiring cognitive flexibility will be examined in smokers and initial data will be collected regarding the effect of tDCS on smoking cessation behaviors. Smokers will be randomized to receive either active or sham tDCS daily for 5 days after which they will attempt to quit smoking. Smoking behavior after the attempted quit date will be assessed at four weekly visits.

Inclusion Criteria:

• Be between the ages of 18 and 64
• Smoked (on average) at least 5 cigarettes per day
• Be motivated to quit smoking

Exclusion Criteria:

• Unstable medical or psychiatric conditions
• Any medical conditions with neurological sequelae
• History of loss of consciousness of greater than 30 minutes duration or loss of consciousness with neurological sequelae
• Have any medical condition or use any medication that would either increase risk of subjects participating in this study (e.g., medications that lower the seizure threshold) or that would impact measures of interest (e.g. smoking cessation medications).
• Are pregnant or planning to become pregnant during the study
• Current use of pacemaker, intracranial electrodes or implanted defibrillator

Number randomized

5 days (time period during which participants received either active or sham tDCS)

Before and after each laboratory session, participants were asked about the presence and severity of 11 specific potential adverse events: 1) Headache; 2) Neck Pain; 3) Scalp Pain; 4) Tingling; 5) Itching; 6) Burning Sensation; 7) Skin Redness; 8) Sleepiness / Fatigue; 9) Poor Concentration; 10) Acute Mood Change; 11) Nausea; 12) An open ended option labeled Other