Recruiting

tACS

Sponsor:

Florida State University

Code:

NCT07924852

Conditions

Cannabis Use Disorder

Major Depression

Anhedonia

Transcranial Alternating Current Stimulation

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Interventions

Transcranial Alternating Current Stimulation Sham

Transcranial Alternating Current Delta Stimulation.

Transcranial Alternating Current Theta Stimulation

Study Details

Brief summary:

Cannabis use disorder (CUD) and major depressive disorder (MDD) are among the most prevalent psychiatric conditions in the United States, affecting an estimated 20.6 million and 21 million adults respectively. Both disorders are characterized by anhedonia, diminished motivation, and blunted neural reward sensitivity. This shared dysregulated reward-processing may reflect a common prefrontal oscillatory dysfunction, centralized in mesolimbic dopaminergic reward pathways. This proposed project aims to investigate if transcranial alternating current (tACS) can modulate motivational behaviours and neural reward responsivity in participants with MDD and/or CUD during an effortful reward task. The investigators hypothesize that delta transcranial alternating current stimulation will produce a greater neural reward responsivity (RewP), and motivational behaviour during an effortful reward task.

Conditions

Cannabis Use Disorder

Major Depression

Anhedonia

Transcranial Alternating Current Stimulation

Study ID

NCT07924852

Start date

Nov 1, 2026

Status verified date

Oct, 2026

Completion date

May 1, 2027

Anticipated

Primary completion date

Apr 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Inclusion Criteria (General):

  • Aged between 18 - 55 years old.
  • Able to provide informed consent
  • Have normal to corrected vision
  • Willing to comply with all study procedures and be available for the duration of the study
  • Speak and understand English.
  • Negative THC saliva test and alcohol breathalyzer at all lab visits.
  • Negative UTOX for any substance other than THC.

Exclusion Criteria (General):

  • Mania history (Bipolar I, or current mania).
  • Psychosis history.
  • Current suicide intent (score >4 on C-SRSS, or intent >0 on SRA)
  • Current moderate-to-severe SUD or AUD (Except CUD and nicotine for NEMO-CUD).
  • Current pregnancy.
  • Seizure, neurological conditions, or brain surgery history.
  • Implanted medical devices (e.g., cochlear implants, cardiac pacemakers).
  • Change in psychotropic medication in the past 3 months (i.e., medication needs to be stable for 12 weeks).
  • Use of seizure threshold lowering medication (e.g., Stimulants, Benzos, SNRIs, Antipsychotics \[Adderall, Vyvanse, Xanax, Wellbutrin, Cymbalta, Lithium\] - SSRIs not exclusionary).

Specific CUD Inclusion:

  • Avg. 6+ cannabis use days per week over the past 3-months, and 24+ cannabis use days in the past 30 days.
  • Primary delta-9 or THC-A cannabis flower or vape concentrate user.
  • Current moderate-to-severe CUD (4+ criteria in the past year, at least one criterion other than craving must be met in the past three months).
  • Cannabis is the primary substance of use (Nicotine dependence is allowable)
  • Not currently receiving treatment for cannabis, planning to immediately quit or reduce use.
  • Lifetime history of MDE/PDD must have lifetime anhedonia symptom and/or heavy cannabis user (3+ sessions daily for at least past year including the past 3-months and past 30 days).

Specific MDD Inclusion:

  • Current MDE diagnosis.
  • No lifetime history of severe SUD.
  • No current moderate-to-severe SUD.
  • 100% of NEMO-MDD participants elevated anhedonia on TEPS-C (i.e., 32 or lower on TEPS-C subscale).

Specific Control Inclusion:

  • No current or historical psychiatric diagnosis.

Study Design

Enrollment

54 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Delta tACS

All participants receive delta (2.5 Hz), theta (6 Hz), and sham tACS across three separate sessions, separated by a 7-10 day washout. Session order is randomised and counterbalanced using a balanced Latin square, within each diagnostic group (CUD, MDD, healthy control). Stimulation is interleaved between the 8 blocks of the EEfRT (e.g., block 1 with stimulation, block 2 without, etc.). EEG activity will be recorded throughout the non-stimulation 4 blocks and proceeding interleaved non-stimulation blocks.

active comparator: Theta tACS

All participants receive delta (2.5 Hz), theta (6 Hz), and sham tACS across three separate sessions, separated by a 7-10 day washout. Session order is randomised and counterbalanced using a balanced Latin square, within each diagnostic group (CUD, MDD, healthy control). Stimulation is interleaved between the 8 blocks of the EEfRT (e.g., block 1 with stimulation, block 2 without, etc.). EEG activity will be recorded throughout the non-stimulation 4 blocks and proceeding interleaved non-stimulation blocks.

sham comparator: Sham tACS

All participants receive delta (2.5 Hz), theta (6 Hz), and sham tACS across three separate sessions, separated by a 7-10 day washout. Session order is randomised and counterbalanced using a balanced Latin square, within each diagnostic group (CUD, MDD, healthy control). Stimulation is interleaved between the 8 blocks of the EEfRT (e.g., block 1 with stimulation, block 2 without, etc.). EEG activity will be recorded throughout the non-stimulation 4 blocks and proceeding interleaved non-stimulation blocks.

Interventions

Transcranial Alternating Current Stimulation Sham

The tACS stimulation is briefly turned on and off over the course of 15-30 seconds.

Transcranial Alternating Current Delta Stimulation.

Approximately 20-minutes of delta stimulation (2.5Hz) applied to F3 (returns AF7, FC5, FC1) and AFz (returns Fp1, Fp2, F2). Transcranial Alternating Current Stimulation Device is NeuroConn DC-Stimulator MC.

Transcranial Alternating Current Theta Stimulation

Approximately 20-minutes of theta stimulation (6Hz) applied to F3 (returns AF7, FC5, FC1) and AFz (returns Fp1, Fp2, F2). Transcranial Alternating Current Stimulation Device is NeuroConn DC-Stimulator MC.

Primary outcome measure

  • Effort-updating behavior during decision period. [ Time Frame: Baseline (Day 0), Sham Session (Day 1-10, or Day 10-20, or Day 20-30), Theta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30), Delta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30). Specific range depends on particular counterbalanced order. ]
  • Delta phase coherence between left lateral and medial frontal electrodes during decision period following a win versus following a loss. [ Time Frame: Baseline (Day 0), Sham Session (Day 1-10, or Day 10-20, or Day 20-30), Theta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30), Delta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30). Specific range depends on particular counterbalanced order. ]
  • Reward positivity amplitude [ Time Frame: Baseline (Day 0), Sham Session (Day 1-10, or Day 10-20, or Day 20-30), Theta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30), Delta Stim. Session (Day 1-10, or Day 10-20, or Day 20-30). Specific range depends on particular counterbalanced order. ]

Central Contacts and Locations

Central contacts

Zoe Howell Doctoral Student PI, M.Res.

850-644-2445brains@psy.fsu.edu

Locations

The Riddle Lab at Florida State University

Recruiting

Tallahassee, Florida, United States, 32306-4301

Contacts

Zoe S Post baccalaureate Researcher, B.A.

(850) 644-9869RiddleLabFSU@gmail.com

More Information

Sponsor

Florida State University

Last update posted

Nov 9, 2026

Last verified

Oct, 2026

Keywords

  • Cannabis Use Disorder
  • Depression
  • Neurostimulation
  • Reward Responsivity

Trial information was received from ClinicalTrials.gov and was last updated on 2026-11-10. This information was provided to ClinicalTrials.gov by Florida State University on 2026-11-09. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.