Establishing the Effect of Flavor on the Addictive Potential of Electronic Cigarettes

Inclusion Criteria

• Aged 21-60
• Smoke filtered cigarettes/machine-rolled cigarettes (≥5 cigarettes per day) or daily e-cigarette use for past year.
• No serious quit attempt in prior month. This includes use of any FDA approved smoking cessation medication (varenicline, bupropion [used specifically as a quitting aid], patch, gum, lozenge, inhaler, and nasal spray) in the past 1 month as an indication of treatment seeking.
• Willing to supplement cigarette smoking with ECIG use for 4 weeks or replace e-cigarette with study product for 4 weeks
• Willing to attend regular visits over a 4-week period (not planning to move, not planning extended vacation, no planned surgeries)
• Willing to undergo two fMRI scans
• Able to read and write in English
• Able to understand and consent to study procedures
• Access to computer with internet service that allows for use of Zoom

Exclusion Criteria

• Impaired smell function as measured via a standardized screening assessment
• Unstable or significant medical condition in the past 12 months (recent heart attack or some other heart conditions, stroke, severe angina including high blood pressure)
• Severe immune system disorders (uncontrolled Human Immunodeficiency virus infection; unstable multiple sclerosis symptoms), respiratory diseases (exacerbations of asthma or chronic obstructive pulmonary disorder, require oxygen, require oral prednisone), kidney (dialysis) or liver diseases (cirrhosis), or any medical disorder/medication that may affect participant safety or biomarker data
• Women who are pregnant (verified by urine pregnancy test at any visit), trying to become pregnant, or nursing
• Medical conditions associated with cognitive impairment or neurological dysfunction
• Severe claustrophobia
• Current depressive or anxiety disorder
• Uncontrolled mental illness or substance abuse or inpatient treatment for these conditions in the past 6 months
• Use of illicit drugs or prescription drugs for non-medical use daily/almost daily or weekly in the past 3 months per National Institute on Drug Abuse (NIDA) Quick Screen, not including use of marijuana
• Any known risk from exposure to high-field strength magnetic fields (e.g., cardiac pacemakers), any irremovable metallic foreign objects in their body (e.g., braces), or a questionable history of metallic fragments which are likely to create artifact on the MRI scans
• Known allergy to propylene glycol or vegetable glycerin
• Other member of household currently participating in the study
• History of a seizure disorder or had a seizure in the past 12 months
• Currently taking medications prescribed to prevent seizures (such as Carbamazepine or Phenobarbital). Using seizure medications for off-label use (indications other than treatment for seizures) will not be included as an exclusion, these will be assessed on a case-by-case basis