tDCS Effects on Resisting Smoking: Dose Ranging Study (RDR)

Inclusion Criteria:

1. Healthy males and females who are between 18 and 60 years of age
2. Report smoking at least 10 cigarettes per day for the past year and have a CO value of > 10ppm at intake
3. Planning to live in the area for at least the next 2 months;
4. Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the combined consent and HIPAA form;
5. Able to communicate fluently in English (speaking, writing, and reading);
6. Smokers who answer yes on a question regarding motivation to quit smoking.

Exclusion Criteria:

Alcohol/Drugs:

1. History or current diagnosis or treatment for alcohol or drug abuse (as reported during phone screen);
2. Positive breath alcohol concentration test (BrAC >0.01) at any study visit. a. Participants testing positive for breath alcohol with a reading equal to or greater than .08 (the legal driving limit) or who are visibly impaired will be instructed not to drive themselves home after the appointment. If a participant needs to use a phone to call for a safe ride home, an office telephone will be made available to the participant.

Medication:

Current use or recent discontinuation (within the last 14 days at the time of Intake) of:

1. Smoking cessation medication (e.g., Zyban, Wellbutrin, Wellbutrin SR, Chantix);
2. Anti-psychotic medications;
3. Nicotine replacement therapy (NRT);
4. GABAergic medications;
5. Glutamatergic medications;

6. Any medication that could compromise participant safety as determined by the Principal Investigator and/or Study Physician.

   Daily use of:

7. Opiate-containing medications for chronic pain;
8. Benzodiazepines.

Medical/Neuropsychiatric:

1. Women who are pregnant, planning a pregnancy, and/or breast feeding. All female subjects will complete a urine pregnancy test at the intake visit and preceding all brain stimulation sessions (4 urine pregnancy tests in total);
2. History of epilepsy or a seizure disorder;
3. History of stroke;
4. Self-reported history of brain or spinal tumor;
5. Self-reported history or current diagnosis of psychosis, including schizophrenia, mania, bipolar disorder, major depression (subjects with a history of major depression but in remission for past 6 months are eligible).

tDCS-related:

1. Self-report of metallic objects in the face or head other than dental apparatus (e.g. braces, fillings, and implants);
2. Self-report of pacemakers or implantable cardioverter-defibrillator (ICD).
3. Self-report of any skull fracture or opening.

General Exclusion:

1. Any medical condition, illness, disorder, or concomitant medication that could compromise participant safety or treatment, as determined by the Principal Investigator;
2. Low or borderline intellectual functioning - determined by a score of less than 90 on the Shipley Institute of Living Scale (SILS) (administered at Intake Visit). The SILS correlates with the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Estimated IQ Test;
3. Inability to provide informed consent or complete any of the study tasks as determined by the Principal Investigator.