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

tDCS Plus Varenicline for Smoking Cessation (NCT06798324) is a Phase 4 interventional studying Nicotine Dependence and Tobacco Smoking, sponsored by Centre for Addiction and Mental Health. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

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.

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 160 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Nicotine Dependence subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Be able to provide informed written consent - Stated willingness to comply with all study procedures - Age 18-85 years - Smoke ≥ 8 cigarettes per day (CPD) - Is seeking treatment for tobacco dependence - Willing to attend the required clinic appointments (Two consecutive weeks, Monday through Friday) - Otherwise healthy (i.e. not suffering from any major illness/condition that would impact their participation in the study) Who Should NOT Join This Trial: - Use of smoking cessation medication (e.g. buproprion, varenicline, NRT, cytisine) in the past 3 months - Current regular use of nicotine-containing products besides cigarettes (e.g. electronic cigarettes, etc.) - Unstable psychiatric illness that would adversely impact study participation and compliance (determined by the QI) - History of seizures/epilepsy - Lifetime history of concussions or head traumas - Current pregnancy or plans to become pregnant - Current pacemakers or implanted electrical devices - Current metal embedded in the skull - Presence of skin lesions, open wounds, or bruising at stimulation sites; or - Contraindications to varenicline use (e.g. pregnant/breastfeeding, alcohol dependence, kidney disease/renal impairment, known hypersensitivity to varenicline) Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Be able to provide informed written consent * Stated willingness to comply with all study procedures * Age 18-85 years * Smoke ≥ 8 cigarettes per day (CPD) * Is seeking treatment for tobacco dependence * Willing to attend the required clinic appointments (Two consecutive weeks, Monday through Friday) * Otherwise healthy (i.e. not suffering from any major illness/condition that would impact their participation in the study) Exclusion Criteria: * Use of smoking cessation medication (e.g. buproprion, varenicline, NRT, cytisine) in the past 3 months * Current regular use of nicotine-containing products besides cigarettes (e.g. electronic cigarettes, etc.) * Unstable psychiatric illness that would adversely impact study participation and compliance (determined by the QI) * History of seizures/epilepsy * Lifetime history of concussions or head traumas * Current pregnancy or plans to become pregnant * Current pacemakers or implanted electrical devices * Current metal embedded in the skull * Presence of skin lesions, open wounds, or bruising at stimulation sites; or * Contraindications to varenicline use (e.g. pregnant/breastfeeding, alcohol dependence, kidney disease/renal impairment, known hypersensitivity to varenicline)

Treatments Being Tested

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.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Centre for Addiction and Mental Health

Toronto, Ontario, Canada

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06798324), the sponsor (Centre for Addiction and Mental Health), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06798324 clinical trial studying?

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 … The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06798324?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06798324?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06798324. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06798324. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-07 · Data from ClinicalTrials.gov.