Recruiting

Observational Study

Sponsor:

Florida State University

Code:

NCT06132581

Conditions

Major Depressive Disorder

Anhedonia

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

Delta-beta tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Theta-gamma tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Sham tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Study Details

Brief summary:

Anhedonia, the inability to seek-out and experience pleasure, is a common symptom in depression that predicts treatment-resistance and is sometimes exacerbated by first-line antidepressants. In our previous research, we found that anhedonia decreases goal-directed behavior and its related neural activity. In this study, we will investigate target engagement from five-consecutive days of stimulation for participants that are within a unipolar major depressive episode and also have high symptoms of anhedonia.

Conditions

Major Depressive Disorder

Anhedonia

Study ID

NCT06132581

Start date

Jan 24, 2024

Status verified date

Aug, 2026

Completion date

Jul 31, 2027

Anticipated

Primary completion date

Jul 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Between the ages of 18 and 65
  • 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
  • Mild suicide risk as determined by the Hamilton Depression Rating Scale (HAM-D; less than 3 for the suicidality item) and non-existent or mild risk according to the Depression Symptom Index Suicidality Subscale (DSI-SS).
  • Patient Health Questionnaire (PHQ-8) greater than or equal to 8 prior to the first session
  • Snaith Hamilton Pleasure Scale (SHAPS) greater than 33 at the first session
  • A diagnosis of major depressive disorder on the Mini International Neuropsychiatric Interview for the DSM-V (MINI)

Exclusion Criteria:

  • ADHD (currently under treatment)
  • Neurological disorders and conditions including, but not limited to history of epilepsy; seizures, except childhood febrile seizures; dementia; history of stroke; Parkinson's disease, multiple sclerosis, cerebral aneurysm; brain tumors
  • Medical or neurological illness or treatment for a medical disorder that could interfere with study participation. For example, unstable cardiac disease, HIV/AIDS, malignancy, liver or renal impairment
  • Prior brain surgery
  • Any brain devices/implants including cochlear implants and aneurysm clips, cardiac pacemaker, or any other implanted electronic device
  • History of current traumatic brain injury
  • Pregnancy (for females)
  • Current severe substance use disorder
  • Claustrophobia
  • Based on the use of MRI, additional exclusion/inclusion criteria are considered. Note that many contraindications for stimulation are common with MRI and thus are not repeated. Participants must not have metal in the body that is ferrous, will be required to remove all jewelry, must not have tattoos on the face or neck, must refrain from wearing metal in clothing (underwire) or active gear (possibility of metallic microparticle technology), must not be a metal worker or have an eye injury involving metal.
  • Anything that in the opinion of the investigator would place the participant at increased risk or preclude the participant's full compliance with or completion of the study
  • DSM-V diagnosis of present moderate or severe substance use disorder or alcohol use disorder, and past severe substance use disorder or alcohol use disorder, or psychotic disorder within the last 12 months

Study Design

Enrollment

72 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Delta-beta tACS

The study is investigating the use of transcranial alternating current stimulation (tACS). The stimulation is delivered at 1 milliampere (mA) zero-to-peak amplitude at the target electrodes and 2 mA zero to-peak amplitude at the return electrode. For the experimental arm, the tACS will be delivered using the cross-frequency stimulation waveform delta-beta (3-20Hz).

active comparator: Theta-gamma tACS

This arm serves as an active control where tACS will be delivered using the cross-frequency stimulation waveform theta-gamma (5-50Hz).

sham comparator: Active-sham tACS

For active sham stimulation, either delta-beta or theta-gamma stimulation is delivered for 15 seconds only at the beginning and end of the stimulation period. This is intended to mimic the skin sensations (e.g., itching, burning, tingling) that are experienced at the onset and offest of stimulation, assisting with blinding the participant's assignment.

Interventions

Delta-beta tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Stimulation will be delivered via the Neurocare Direct Current Stimulator Multi-Channel 4, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research. The electrical waveform for stimulation was designed to mimic delta-beta coupling in the brain.

Theta-gamma tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Stimulation will be delivered via the Neurocare Direct Current Stimulator Multi-Channel 4, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research. The electrical waveform for stimulation was designed to mimic theta-gamma coupling in the brain and is used as an active comparator.

Sham tACS via the Neurocare Direct Current Stimulator Multi-Channel 4

Stimulation will be delivered via the Neurocare Direct Current Stimulator Multi-Channel 4, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research. The electrical waveform is randomly selected to be the theta-gamma or delta-beta waveform, but the stimulation is delivered for only a brief period of time of approximately 30 seconds, which is not sufficient to produce a meaningful dose to the brain. This placebo, or sham, stimulation is designed to mimic the sensation of receiving stimulation.

Primary outcome measure

  • Change in coupling strength between prefrontal and posterior cortex [ Time Frame: 1 week ]

Central Contacts and Locations

Central contacts

Justin M Riddle, PhD

850-645-2389jriddle@fsu.edu

Locations

Florida State University

Recruiting

Tallahassee, Florida, United States, 32306

Contacts

Justin M Riddle, PhD

850-645-2389jriddle@fsu.edu

Principal Investigator:

Justin M Riddle, PhD

More Information

Sponsor

Florida State University

Last update posted

Aug 31, 2026

Last verified

Aug, 2026

Keywords

  • Transcranial alternating current stimulation
  • Goal-directed behavior
  • Cross-frequency coupling

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Florida State University on 2026-08-31.