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

The current study aims to establish proof-of-concept that neural cue-reactivity can serve as an early, objective marker of electronic cigarette (ECIG) addictive potential. Further, this study will examine the effect of flavor and nicotine concentration on the addictive potential of ECIGs to aid research informing U.S. Food and Drug Administration (FDA) flavor regulations and smoking cessation.

Study Overview

• Status: Completed
• Conditions: Tobacco Dependence
• Intervention / Treatment: Other: Nicotine Containing ECIG with tobacco flavor; Other: Placebo ECIG with Tobacco Flavor; Other: Nicotine Containing ECIG with Strawberry Vanilla Flavor; Other: Placebo ECIG with Strawberry Vanilla Flavor

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Hershey, Pennsylvania, United States, 17033
      • Penn State Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Aged 21-60
2. Smoke filtered cigarettes/machine-rolled cigarettes (≥5 cigarettes per day) or daily e-cigarette use for past year.
3. 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.
4. Willing to supplement cigarette smoking with ECIG use for 4 weeks or replace e-cigarette with study product for 4 weeks
5. Willing to attend regular visits over a 4-week period (not planning to move, not planning extended vacation, no planned surgeries)
6. Willing to undergo two fMRI scans
7. Able to read and write in English
8. Able to understand and consent to study procedures
9. Access to computer with internet service that allows for use of Zoom

Exclusion Criteria:

1. Impaired smell function as measured via a standardized screening assessment
2. 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)
3. 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
4. Women who are pregnant (verified by urine pregnancy test at any visit), trying to become pregnant, or nursing
5. Medical conditions associated with cognitive impairment or neurological dysfunction
6. Severe claustrophobia
7. Current depressive or anxiety disorder
8. Uncontrolled mental illness or substance abuse or inpatient treatment for these conditions in the past 6 months
9. 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
10. 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
11. Known allergy to propylene glycol or vegetable glycerin
12. Other member of household currently participating in the study
13. History of a seizure disorder or had a seizure in the past 12 months
14. 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: 0mg/ml Tobacco Flavor ECIG; Participants will be provided with an ECIG containing 0mg/ml nicotine concentration and a tobacco flavor.	Other: Placebo ECIG with Tobacco Flavor; Participants will be provided with an EGO style ECIG to be used for 28 days. The EGO style ECIG is a "vape pen-style" device that comprises of a rechargeable battery and a tank containing liquid. Those in this intervention group will receive an ECIG with 0mg/ml nicotine concentration and a tobacco flavor.
Placebo Comparator: 0mg/ml Strawberry Vanilla Flavor ECIG; Participants will be provided with an ECIG containing 0mg/ml nicotine concentration and a strawberry vanilla flavor.	Other: Placebo ECIG with Strawberry Vanilla Flavor; Participants will be provided with an EGO style ECIG to be used for 28 days. The EGO style ECIG is a "vape pen-style" device that comprises of a rechargeable battery and a tank containing liquid. Those in this intervention group will receive an ECIG with 0mg/ml nicotine concentration and a strawberry vanilla flavor.
Experimental: 18mg/ml Tobacco Flavor ECIG; Participants will be provided with an ECIG containing 18mg/ml nicotine concentration and a tobacco flavor.	Other: Nicotine Containing ECIG with tobacco flavor; Participants will be provided with an EGO style ECIG to be used for 28 days. The EGO style ECIG is a "vape pen-style" device that comprises of a rechargeable battery and a tank containing liquid. Those in this intervention group will receive an ECIG with 18mg/ml nicotine concentration and a tobacco flavor.
Experimental: 18mg/ml Strawberry Vanilla Flavor ECIG; Participants will be provided with an ECIG containing 18mg/ml nicotine concentration and a strawberry vanilla flavor.	Other: Nicotine Containing ECIG with Strawberry Vanilla Flavor; Participants will be provided with an EGO style ECIG to be used for 28 days. The EGO style ECIG is a "vape pen-style" device that comprises of a rechargeable battery and a tank containing liquid. Those in this intervention group will receive an ECIG with 18mg/ml nicotine concentration and a strawberry vanilla flavor.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Baseline Neural Flavor Cue-reactivity at Baseline	Functional magnetic resonance imaging (fMRI) will be used to measure blood oxygen-level dependent (BOLD) signal in response to tobacco vs. strawberry-vanilla ECIG flavors at baseline. The means reported are the average percentage of BOLD signal change between the fMRI task odor conditions (tobacco vs. strawberry) identified using a whole-brain one-sample t-test with FSL software. Positive values indicate stronger BOLD signal during tobacco odor cues and negative values indicate stronger BOLD signal during strawberry odor cues.	Baseline
Changes in Neural Flavor Cue-reactivity Across Nicotine Groups	Functional magnetic resonance imaging (fMRI) will be used to measure changes in blood oxygen-level dependent (BOLD) signal for the tobacco>strawberry contrast across 18 mg/ml vs. 0 mg/ml nicotine concentration groups from baseline to 4-weeks post-randomization using a whole-brain repeated measures ANOVA with FSL software. The means reported are the difference (4-week post-intervention - baseline) of the average percentage of BOLD signal change between the fMRI task odor conditions (tobacco vs. strawberry). Positive values indicate increases in tobacco>strawberry BOLD signal and negative values indicate decreases in tobacco> strawberry BOLD signal.	Baseline to 4-weeks
Changes in Neural Flavor Cue-reactivity Across Flavor Groups	Functional magnetic resonance imaging (fMRI) will be used to measure changes in blood oxygen-level dependent (BOLD) signal for the tobacco > strawberry contrast across flavor groups (tobacco vs. strawberry) from baseline to 4-weeks post-randomization. The means reported are the difference (4-week post-intervention - baseline) of the average percentage of BOLD signal change between the fMRI task odor condition (tobacco vs. strawberry) identified using a whole-brain repeated measures ANOVA with FSL software. Positive values indicate increases in tobacco>strawberry BOLD signal and negative values indicate decreases in tobacco> strawberry BOLD signal.	Baseline to 4-weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ECIG Dependence	Changes in self-reported ECIG dependence will be measured using the Penn State Electronic Cigarette Dependence Index (PSECDI). Total scores on this 10-item measure range from 0 to 20, with higher scores indicating higher levels of e-cigarette dependence. The means reported here are the week 4 - week 2 difference scores of the total dependence score. Positive means indicate increases in e-cigarette dependence, while negative means indicated decreases in e-cigarette dependence.	2-weeks post-randomization to 4-weeks post-randomization
ECIG Liking and Satisfaction	Changes in subjective experiences of ECIG use related to liking and satisfaction will be collected via a self-report survey. The survey consists of 21-items (7-reversed scored) with response options on a 7-point likert scale and total scores ranging from 0 to 126. Higher scores indicate more ECIG liking and satisfaction. The means reported here are the difference of the total scores at week 4 - week 2, with positive means indicating increases in e-cigarette liking and negative means indicating decreases in liking. Note that standard deviation cannot be reported for groups with only one participant.	2-weeks to 4-weeks
Craving to Smoke/Vape	Changes in self-reported craving to smoke/vape were measured with 3 questions on amount, intensity, and self-control using visual analogue scales ranging from 0 to 10 prior to completing the functional MRI scan. Total scores range from 0 to 30 and higher scores indicate more craving. The means reported here are week 4 post-intervention - baseline difference scores of the total craving score. Positive means indicate increases in craving, while negative means indicate decreases in craving.	Baseline to 4-weeks post-randomization

Collaborators and Investigators

• Sponsor: Milton S. Hershey Medical Center
• Collaborators: National Institute on Drug Abuse (NIDA)

Study record dates

Study Major Dates

• Study Start (Actual): November 4, 2019
• Primary Completion (Actual): April 30, 2024
• Study Completion (Actual): April 30, 2024

Study Registration Dates

• First Submitted: April 4, 2019
• First Submitted That Met QC Criteria: April 4, 2019
• First Posted (Actual): April 8, 2019

Study Record Updates

• Last Update Posted (Actual): June 22, 2025
• Last Update Submitted That Met QC Criteria: June 4, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: smoking; electronic cigarettes; cue-reactivity; flavor
• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Tobacco Use Disorder; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Neurotransmitter Agents; Cholinergic Agents; Ganglionic Stimulants; Nicotinic Agonists; Cholinergic Agonists; Nicotine
• Other Study ID Numbers: 11837; R03DA047582 (U.S. NIH Grant/Contract)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No