NCT06798324

tDCS Plus Varenicline for Smoking Cessation

Using Non-Invasive Brain Stimulation (tDCS) as an Adjunct to Varenicline for the Treatment of Tobacco Dependence: a Randomized Controlled Trial

• Status: Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 160 (estimated)
• Sponsor: Centre for Addiction and Mental Health · Academic / Other
• Sex: All
• Age: 18 Years – 85 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to determine if active transcranial direct current stimulation (tDCS) plus varenicline is an effective, safe and accessible treatment option for smoking cessation. The main questions this trial aims to answer are: 1. Does active tDCS plus varenicline improve short-term and long-term smoking abstinence rates compared to sham tDCS plus varenicline? 2. Are the safety profiles between active tDCS plus varenicline and sham tDCS plus varenicline different? The tDCS treatment schedule includes 10 daily sessions for the first 2 weeks (M to F), followed by 5 single bi-weekly booster sessions for the remainder of the treatment period. Participants will come in-person for two follow-up sessions to assess smoking behaviour at 6- and 12-months post-treatment.

Detailed description

Smoking remains the leading cause of lung cancer globally, with cigarette smokers being about 20 times more likely to develop lung cancer than non-smokers. Despite the availability of effective treatments and extensive public health efforts, quitting smoking remains a significant challenge. Varenicline is currently the most effective medication for smoking cessation, yet most users relapse within the first year. No new medications for smoking cessation have come to market in the past two decades, and as such there is a critical need to optimize existing treatments. Combining treatment modalities can produce therapeutic synergism and improve overall treatment outcomes. Non-invasive brain stimulation techniques have become a popular area of research as a treatment option for substance use disorders with growing evidence of their effectiveness for a variety of addictions. One of these techniques, transcranial direct current stimulation (tDCS), has demonstrated potential in modulating the neuroadaptations associated with chronic smoking and relapse risk. A prior pilot study in our lab found that adjunct active tDCS doubled varenicline's effectiveness at end of treatment. Therefore, the objectives for this trial are as follows: 1. To determine the short-term efficacy of active anodal tDCS to the left DLPFC plus varenicline compared to sham tDCS plus varenicline. 2. To determine the effect of active anodal tDCS to the left DLPFC plus varenicline on sustained abstinence over time. 3. To determine the safety of active anodal tDCS to the left DLPFC plus varenicline compared to sham tDCS plus varenicline. This study will be a double-blind sham-controlled randomized clinical trial whereby 160 daily cigarette smokers will be recruited. After confirming eligibility at an assessment visit, participants will be randomized (1:1) to one of two groups: 1) Experimental group of active tDCS sessions plus 12 weeks of 1 mg varenicline bid (n=80); and 2) Control group of sham tDCS sessions plus 12 weeks of 1 mg varenicline bid (n=80). Participants will start varenicline treatment on the same day as the first tDCS session, and will follow a standard dose escalation schedule. The tDCS treatment schedule includes 10 daily sessions for the first 2 weeks (M to F), followed by 5 in-person bi-weekly booster sessions for the remainder of the treatment period, and then 2 in-person follow-up sessions to assess smoking behaviour at 6- and 12-months post-treatment. At the 1st daily session, participants will come in-person to be trained on using the tDCS device and provided with a study kit including all relevant study equipment. The following 8 daily sessions will occur remotely, and be monitored by research personnel over Webex. The 10th daily tDCS session will occur in-person, with participants returning the study kit. All 5 bi-weekly booster sessions will occur in-person. Total Study duration (with follow-up) is 12 months.

Conditions

• Nicotine Dependence
• Tobacco Smoking
• Smoking Cessation
• Nicotine Use Disorder
• Tobacco Use Disorder
• Substance Use Disorders

Interventions

Type	Name	Description
DEVICE	Active Transcranial Direct Current Stimulation (tDCS)	Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation. Active tDCS involves brief (e.g., 20-min) application of weak electric current (e.g., 2 mA) to the scalp. The tDCS device that will be used for this study is the Soterix 1x1 mini-CT.
DRUG	Varenicline 1mg BID	Varenicline is the most effective approved treatment for quitting smoking. Varenicline as per standard prescribing for dose escalation (i.e. Days 1 to 3: 0.5 mg once daily; Days 4 to 7: 0.5 mg twice daily; Days 8 to end of treatment: 1 mg twice daily) will be given concurrently over the same 2 weeks as the tDCS protocol and continue for an additional 10 weeks as per standard treatment duration recommended on the product monograph for a total of 12 weeks of varenicline treatment. Dose adjustments due to adverse events will be allowed (i.e. decrease to 0.5 mg twice daily). The target quit date for smoking cessation will be on the last day of the two weeks of daily tDCS which corresponds to the recommended quit date after starting varenicline treatment.
DEVICE	Sham Transcranial Direct Current Stimulation (tDCS)	Sham tDCS consists of 30s of 2 mA at the beginning and at the end of the 6 session (ramp up and down), then receiving 0 mA stimulation for the middle 19 min. The tDCS device that will be used for this study is the Soterix 1x1 mini-CT.

Timeline

• Start date: 2025-03-10
• Primary completion: 2028-01-20
• Completion: 2028-08-01
• First posted: 2025-01-29
• Last updated: 2025-08-12

Locations

1 site across 1 country: Canada

Regulatory

• FDA-regulated device study