Applying Neuromodulation to Boost the Efficacy of Motivational Interviewing

August 25, 2026 updated by: The Mind Research Network

The goal of this clinical trial is to learn how adding brain stimulation to a brief counseling session affects adults with cannabis use disorder. The counseling session uses motivational interviewing, which helps people talk through their reasons for changing or not changing cannabis use. The brain stimulation is called transcranial alternating current stimulation (tACS). tACS uses electrodes on the scalp to give a very weak electrical current for a short time.

The main questions it aims to answer are:

  • Does active tACS affect what participants say during the counseling session?
  • Does active tACS change brain activity after the session?
  • Is active tACS related to less cannabis use during the month after the session?

Researchers will compare motivational interviewing with active tACS to motivational interviewing with placebo stimulation. Placebo stimulation uses the same setup but does not provide the active 30-minute stimulation. Participants will be assigned by chance to one of these groups, and neither participants nor the study staff member running the session will know which type of stimulation is used.

Participants will complete questionnaires, breath and urine tests, a recorded counseling session during active or placebo stimulation, MEG and MRI brain scans, daily text-message check-ins about cannabis use, and follow-up questionnaires about one month later.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Motivational interviewing is a widely used counseling approach for substance use disorders, including cannabis use disorder. A central proposed mechanism of motivational interviewing is that clients resolve ambivalence by hearing themselves express reasons for change and reasons for maintaining current behavior. Prior empirical and meta-analytic research has linked these within-session speech patterns with subsequent substance use outcomes.

This proof-of-concept randomized, double-blind, sham-controlled trial tests whether transcranial alternating current stimulation (tACS) can modulate this mechanism during a motivational interviewing session for adults with cannabis use disorder. tACS is a noninvasive form of brain stimulation that delivers weak sinusoidal electrical current through scalp electrodes. In this study, stimulation is designed to target beta-band activity in left inferior temporal cortex, a region and frequency range implicated in speech acts and commitment-related language. Pilot work suggests that beta-band activity may be stronger during statements favoring behavior change than during statements favoring continued substance use, and that tACS during motivational interviewing is feasible.

Participants are assigned to motivational interviewing with active tACS or motivational interviewing with sham stimulation. Both groups receive a single motivational interviewing session focused on cannabis-use ambivalence while the stimulation device and scalp electrodes are in place. The active condition includes approximately 30 minutes of 20-Hz beta-frequency stimulation focused on left inferior temporal cortex at 2.0 mA total combined current across electrodes. The sham condition uses the same setup with brief ramping procedures to emulate the sensations of active stimulation but without active stimulation during the intervention period.

The study evaluates whether active tACS, compared with sham stimulation, affects client speech during the motivational interviewing session, post-session brain activity, and cannabis use during the month after the session. Session audio is analyzed to quantify speech that favors change and speech that favors continued cannabis use. Neuroimaging measures include magnetoencephalography (MEG) and magnetic resonance imaging (MRI) after the intervention session. Post-stimulation resting MEG is co-registered to structural MRI to estimate, with particular interest in beta-band activity in left temporal cortex in MEG. Near-term cannabis use is assessed with daily self-report check-ins and a follow-up assessment approximately one month after baseline.

The trial is intended to provide mechanistic evidence about whether noninvasive neuromodulation can alter a candidate process of behavior change during psychotherapy. The study is not designed to provide ongoing substance use disorder treatment, but to test whether pairing tACS with a brief motivational interviewing session changes speech, brain activity, and short-term cannabis-use outcomes relative to a sham-stimulation comparison.

Study Type

Interventional

Enrollment (Estimated)

82

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Research Coordinator
  • Phone Number: 505-226-2323
  • Email: enact@mrn.org

Study Locations

  • United States
    • New Mexico
      • Albuquerque, New Mexico, United States, 87106
        • The Mind Research Network

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • self-identification as having problematic cannabis use
  • age 21-65 years
  • SCID-5-RV module E indicating current cannabis use disorder

Exclusion Criteria:

  • currently engaged in treatment for any substance use disorder (SUD)
  • receiving treatment for any SUD within the prior 30 days
  • history of brain injury or major neurological diagnosis, vascular/neurodegenerative disorder, or complex primary headache disorder
  • evidence of current psychosis
  • past-year substance use disorder other than cannabis, alcohol, or nicotine
  • positive urine drug screen for any illicit drug other than cannabis
  • current or recent (past-month) medically significant withdrawal
  • MRI/tACS contraindications, including pregnancy
  • impaired hearing (psychotherapy using American Sign Language is not possible within the scope of this study)
  • insufficient corrected visual acuity to complete the assessment instruments
  • unable to read/speak English fluently
  • unable to provide valid informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: MI+stim
30 minutes of motivational interviewing (MI) with active transcranial alternating current stimulation (tACS)
Device: transcranial alternating current stimulation
Active transcranial alternating current stimulation
Other Names:
  • tacs
Behavioral: Motivational interviewing (MI)
30 minute motivational interviewing session
Placebo Comparator: MI+sham
30 minutes of motivational interviewing (MI) with sham transcranial alternating current stimulation (tACS)
Device: sham transcranial alternating current stimulation
sham transcranial alternating current stimulation including 30 seconds of ramp-up and ramp-down at the beginning and end of the session, with no stimulation between ramping procedures.
Other Names:
  • sham
  • tacs
Behavioral: Motivational interviewing (MI)
30 minute motivational interviewing session

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Client speech
Time Frame: Baseline
Motivational Interviewing Skill Code-defined change talk (CT; higher scores are better) and sustain talk (ST; lower scores are better) assessed via CASAA Application for Coding Treatment Interactions and session audio recording.
Baseline
Cannabis use
Time Frame: 30 days
Timeline follow-back (TLFB) measure
30 days
MEG
Time Frame: Baseline
Beta-band activity assessed using MNE-python
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cannabis use
Time Frame: 30 days
Urine drug screen (UDS) measure
30 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The Mind Research Network

Collaborators

National Institute on Drug Abuse (NIDA)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

August 1, 2026

Primary Completion (Estimated)

August 1, 2028

Study Completion (Estimated)

August 1, 2028

Study Registration Dates

First Submitted

August 13, 2026

First Submitted That Met QC Criteria

August 21, 2026

First Posted (Actual)

August 26, 2026

Study Record Updates

Last Update Posted (Actual)

August 27, 2026

Last Update Submitted That Met QC Criteria

August 25, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20-156
  • 1UG3DA061594 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

There be maximum appropriate sharing of scientific data underlying peer-reviewed publications and other findings resulting from the work supported by this award (including preprints, refereed papers reported at conferences, and other findings). The scientific data underlying peer-reviewed publications will be shared by the time of publication, or for other findings, by the end of the period of performance, which includes no-cost extensions. Data from participants who have opted not to share their data will not be shared or uploaded. All data sharing is contingent on review and approval by the supervising IRB. All structural MRIs will be de-faced before sharing or uploading into the repository, and the participant's head/face shape collected during MEG preparation will be removed before uploading/sharing. Instead, the MEG-MRI transformation matrix will be uploaded and shared. Neither audio recordings nor data derived from audio recordings will be shared or uploaded.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe