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Not yet recruitingNCT07845409TACTIC-BDUpdated Sep 28, 2026

Targeted Alternating Current and Cognitive Training Intervention for Cognitive Control in Bipolar Disorders

An interventional study of Soterix 1x1 tES mini-CT in Bipolar Disorder, Bipolar and Related Disorders and Veterans, sponsored by VA Office of Research and Development. Not yet recruiting at 1 site in United States. Open to participants aged 21 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-28.

Sponsored by VA Office of Research and Development · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
138
Allocation
Randomized
Ages
21 Years and older
Sex
All
01

Study summary

This study is testing whether a type of gentle brain stimulation, combined with computer-based brain training exercises, can help improve thinking skills in Veterans with bipolar disorder. Veterans with bipolar disorder may have difficulty with skills like stopping to think before acting or adjusting their behavior when things change - problems that can affect daily life and have been linked to a higher risk of serious outcomes.

In this study, Veterans with bipolar disorder will complete brain training exercises at home on a computer, paired with a mild electrical brain stimulation called transcranial alternating current stimulation (tACS), delivered through a small headband worn on the forehead. Some participants will receive real stimulation and some will receive an inactive ("sham") version, and neither participants nor most study staff will know which one a person is receiving. All participants will also complete brain wave recordings (EEG), interviews, questionnaires, and various thinking tasks before and after the study to measure any changes. A separate group of Veterans without bipolar disorder will complete the same tests, without any brain stimulation or training, to help researchers understand how much change would happen naturally just from taking the same tests more than once.

The goal of this research is to learn whether this combined treatment approach is safe, tolerable, and helpful for improving thinking skills in Veterans with bipolar disorder, and whether Veterans find it an acceptable treatment worth continuing.

Read the detailed description

Veterans with bipolar disorder (BD) are at elevated risk for suicide, recurrent homelessness, and disability, and existing pharmacological and psychosocial treatments show limited efficacy for the cognitive dysfunction that underlies these outcomes. Cognitive control (CC) - encompassing response inhibition, error monitoring, and adaptive responding to changing contingencies - is a core, trait-like neurocognitive deficit in BD that persists across mood states (mania, depression, euthymia) and is mechanistically linked to symptom severity and suicidality. No prior studies have examined neuromodulation targeting CC processes in Veterans with BD.

This study is a randomized, double-blind, sham-controlled trial testing whether transcranial alternating current stimulation (tACS) targeting frontal theta oscillations, delivered concurrently with CC-relevant cognitive training, improves neural and behavioral indices of CC beyond cognitive training alone. Ninety-two Veterans with a DSM-5 diagnosis of Bipolar I, Bipolar II, or Other Specified Bipolar Disorder will complete a baseline assessment battery, including self-report measures, EEG (resting-state and task-based), and behavioral paradigms indexing CC in both affective and non-affective contexts (e.g., Go/NoGo, Dot Pattern Expectancy, Monetary Incentive Delay tasks). Participants will then be randomized 1:1 to 10 sessions of active (5Hz, 1mA) or sham frontal theta-frequency tACS (electrodes at F3/F4), each paired with concurrent computerized cognitive training (BrainHQ) targeting working memory, inhibitory control, set-shifting, and attention. All intervention sessions will be self-administered in participants' homes under real-time remote supervision via videoconference. Follow-up assessments repeating the baseline CC battery will occur at approximately 1-week and 2-months post-intervention.

An additional 46 Veterans without major psychopathology will complete an identical assessment schedule (baseline and two follow-up visits) without any intervention, in order to establish practice-effect benchmarks independent of neuromodulation, cognitive training, or mood symptomatology - a design feature intended to isolate true intervention effects from repeated-testing effects, consistent with methodological recommendations for cognitive intervention trials in serious mental illness.

Primary outcomes include change over time in behavioral (d' on Affective and non-affective Go/NoGo and Dot Pattern Expectancy tasks; Trail Making Test-B completion time) and EEG (frontal theta amplitude during the Monetary Incentive Delay task; error-related positivity during the Go/NoGo task) indices of CC, comparing active versus sham tACS groups relative to the practice-effect benchmark established by the control cohort. Secondary outcomes include self-report CC measures (UPPS-P, MPQ-BF Control subscale), qualitative acceptability data from semi-structured exit interviews with the BD cohort, and cross-sectional associations between baseline CC indices and lifetime severity of (hypo)mania, depression, and suicidality. Exploratory analyses will examine intervention effects on general cognitive functioning and the influence of subthreshold mood symptoms on treatment response.

This study is the first to test remotely delivered tACS combined with cognitive training in Veterans with BD, and is designed to establish feasibility, acceptability, and preliminary efficacy data to inform future trials examining long-term effects on BD illness course, including suicidality and functional outcomes.

02

Conditions studied

  • Bipolar Disorder
  • Bipolar and Related Disorders
  • Veterans
  • Suicide
  • Suicidal Ideation
  • Mental Disorders

Keywords

  • Transcranial Direct Current Stimulation
  • Electric Stimulation Therapy
  • Cognitive Remediation
  • Cognitive Training
  • Executive Function
  • Cognition
  • Inhibition, Psychological
  • Impulsive Behavior
  • Electroencephalography
  • Randomized Controlled Trial
  • Double-Blind Method
  • Telemedicine
  • Neuropsychological Tests
03

Who can participate

Ages eligible
21 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  1. Veteran
  2. Capacity to provide voluntary informed consent
  3. English language fluency
  4. Stable dose of prescription and non-prescription medications that may impact cognition for at least 3 weeks prior to consent
  5. Bipolar Disorder (BD) cohort only: A primary diagnosis of Bipolar I Disorder, Bipolar II Disorder, or Other Specified Bipolar Disorder (i.e., those with major depressive episodes and hypomania that meet all episode criteria but for duration)

Exclusion criteria

Exclusion Criteria:

  1. Presence of a medical, psychiatric, physical or non-physical disease, disorder, condition, injury, disability or pre-existent history such that study participation, in the opinion of the study investigators: a) May pose a significant risk to the participant, b) raises the possibility that the participant is unlikely to successfully complete all the requirements of the study according to the study protocol, or c) might adversely impact the integrity of the data or the validity of the study results. Specific conditions may include (but are not limited to) a history of brain tumor near the stimulation site, brain surgery, severe traumatic brain injury (TBI) (LOC >24 hours, GCS 3-8), stroke with current sequalae, epilepsy, Multiple Sclerosis, Huntington's Disease, ALS, ataxia, aphasia, Alzheimer's Disease, dementia, cardiac pacemaker or defibrillator, blindness, or deafness.
  2. Bipolar Disorder (BD) cohort only: a) Current/acute episode criteria met for any Bipolar Disorder (BD) episode (i.e., hypomania, mania, depression) for the month prior to consent as assessed by SCID-5-RV's Module A, b) Current/acute substance use disorder with severe specifier and/or evidence of withdrawal or increased tolerance, as assessed by SCID-5-RV's Module E, c) Contraindications for transcranial alternating current stimulation (tACS), e.g., metallic cranial or facial implant, dermatologic conditions on the forehead, etc. d) No or limited internet connection in their home
  3. Control cohort only: a) Current or lifetime bipolar disorders or symptoms of psychosis assessed by SCID-5-RV, and/or b) Clinically significant mental health disorders within 2 years of consent (e.g., major depressive disorder, generalized anxiety disorder, post-traumatic stress disorder, substance use disorder as specified in 2b) as assessed by SCID-5-RV
  4. Court-appointed legal guardianship
  5. Cognitive training or neuromodulation treatments for clinical or research purposes within 30 days of consent or during study period (consent to final follow-up)
  6. Electroconvulsive Therapy (ECT) within 12 months of consent or during study period
  7. Baseline MoCA score \<18 or MoCA-Blind score \<19
  8. Baseline acute severe suicidal ideation as determined by a score > 3 on the Depressive Symptom Index-Suicidality Subscale (DSI-SS)
  9. Positive pregnancy screen in participants of childbearing potential
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
138 participants (estimated)

Study arms

  • Experimental
    Active transcranial alternating current stimulation (tACS)+ Cognitive Training

    Veterans with bipolar disorder randomized to this arm receive 10 sessions of active frontal theta-frequency transcranial alternating current stimulation (tACS; 5Hz, 1mA, delivered via electrodes at F3/F4), administered concurrently with computerized cognitive training (BrainHQ) targeting working memory, inhibitory control, set-shifting, and attention. Sessions are self-administered at home under real-time remote supervision.

    Device: Soterix 1x1 tES mini-CT

  • Placebo comparator
    Sham transcranial alternating current stimulation (tACS)+ Cognitive Training

    Veterans with bipolar disorder randomized to this arm receive 10 sessions of sham (inactive) tACS, using identical electrode placement, session structure, and setup as the active arm, but without sustained active current delivery beyond a brief onset sensation. This arm receives the same concurrent cognitive training (BrainHQ) as the active arm, allowing isolation of tACS-specific effects beyond cognitive training alone.

    Device: Soterix 1x1 tES mini-CT

  • No intervention
    Control (No Intervention)

    Veterans without major psychopathology complete the same baseline and follow-up assessment schedule (self-report, behavioral, and EEG measures of cognitive control) as the BD cohort, without receiving cognitive training, tACS, or sham tACS. This arm establishes practice-effect benchmarks to distinguish true intervention effects from repeated-testing effects. This arm is assigned by eligibility status, not randomization.

Interventions

  • DeviceSoterix 1x1 tES mini-CT

    The Soterix 1x1 tES mini-CT is a compact, battery-powered transcranial electrical stimulation device manufactured by Soterix Medical, Inc., designed to deliver low-intensity electrical current (including tDCS and tACS waveforms) through scalp electrodes for research use. The device is part of Soterix's Remote Neuromodulation platform, specifically engineered to support safe, self-administered stimulation in the home setting under remote supervision. It is used in conjunction with the SNAPstrap headgear and SNAPpad electrodes for standardized, simplified electrode placement, and is programmed via subject- and session-specific, one-time-use activation codes that pre-set stimulation parameters (intensity, duration, and active/sham condition), preventing participant alteration of stimulation settings. The device is labeled by the manufacturer for investigational use only under U.S. federal law.

    Also known as: Soterix Medical Remote Neuromodulation

05

What researchers measure

Primary outcomes

  1. Affective Go/NoGo task

    The Affective Go/NoGo task assesses response inhibition within an emotionally salient context, in contrast to purely non-affective measures of cognitive control. On each trial, a word with positive, negative, or neutral emotional valence is presented at the center of the screen; participants are instructed to respond as quickly as possible to target words of a designated valence (e.g., positive) while withholding responses to distractor words of the other two valences (e.g., negative or neutral). This design requires participants to inhibit prepotent responses to emotionally salient but task-irrelevant stimuli, capturing the interaction between affective processing and cognitive control. Affective response inhibition will be indexed by overall task accuracy using d', consistent with signal detection approaches to response inhibition performance.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  2. Dot Pattern Expectancy (DPX) task

    The Dot Pattern Expectancy (DPX) is a dot-based variant of the AX-Continuous Performance Test (AX-CPT) used to assess cognitive control in the context of proactive response preparation and contextual updating. On each trial, participants are presented with a cue (white) followed by a probe (light blue), separated by a 2500-3500 ms interval; a target response is required only when a valid cue ("A") is followed by a valid probe ("X"), yielding four trial types: AX (target), AY, BX, and BY (nontarget). The outcome measure is overall task accuracy, calculated using the discriminability index (d'), a signal detection measure calculated as the z-transformed hit rate minus the z-transformed false alarm rate, adjusted for performance. The d' score is a continuous measure with a range of -4 to 4; higher d' scores indicate better discrimination between target and non-target trials, reflecting stronger cognitive control.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  3. Trail Making Test-B (TMT-B)

    The Trail Making Test-B (TMT-B) is a widely used, paper-and-pencil neuropsychological measure of cognitive flexibility and set-shifting. Participants are asked to draw a line connecting a series of numbered and lettered circles in alternating sequential order (e.g., 1-A-2-B-3-C), as quickly and accurately as possible. Because successful performance requires continuously shifting attention between two different response sets, TMT-B is considered a sensitive index of executive/cognitive control, with longer completion times reflecting greater difficulty in adaptive, flexible responding. The primary outcome measure is time to completion.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  4. Go/NoGo task

    EEG will be recorded during a Go/NoGo task in which participants are instructed to respond via button press to any letter other than "X" (Go trials) and to withhold response when an "X" appears (NoGo trials), while responding as quickly as possible and minimizing errors. Participants complete two blocks totaling 228 trials, with approximately 24% designated as NoGo trials; letters are presented for 2000 ms with a randomized intertrial interval of 800-1200 ms. Because Go trials occur more frequently than NoGo trials, the task design induces a prepotent tendency to respond, increasing demand on inhibitory control during NoGo trials. Behavioral accuracy will be indexed by d'. The primary neural outcome of interest is the event-related potential (ERP) time-locked to the button-press response reflecting conscious error detection, indexed by error-related positivity (Pe) amplitude.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  5. Monetary Incentive Delay (MID) task

    The Monetary Incentive Delay (MID) task assesses neural responses associated with anticipating and receiving monetary outcomes. Participants complete 180 trials across three blocks; each trial begins with a 250 ms cue indicating a potential gain, loss, or neutral outcome, denoted by line markings corresponding to magnitude ($0.25-$5.00). Following a 1,500 ms fixation period, a brief target (180-280 ms) appears, requiring a speeded button press to win or avoid losing money; target duration is adaptively titrated to maintain approximately 70% accuracy across participants. Trial outcome feedback is presented for 1,650 ms, followed by a 500 ms display of cumulative earnings, and participants are compensated with a portion of their total winnings at the conclusion of the task. EEG is recorded continuously throughout the task, with frontal theta power during the reward anticipation period serving as the primary neural outcome measure.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

Secondary outcomes

  1. UPPS-P Impulsive Behavior Scale

    The UPPS-P is a self-report measure conceptualizing impulsivity as a multi-faceted, multi-dimensional construct comprising five distinct trait subscales: Negative Urgency (tendency to act rashly during negative emotions), Lack of Premeditation (tendency to act without forethought), Lack of Perseverance (inability to remain focused on a task), Sensation Seeking (tendency to pursue novel and thrilling experiences), and Positive Urgency (tendency to act rashly during positive emotions). This study will use the 20-item short-form version of the UPPS-P, which has demonstrated high reliability and validity.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  2. MPQ-BF

    The MPQ-BF is a self-report personality assessment comprising 11 primary trait scales that load onto three higher-order temperament factors. This study will use the Control primary scale, which assesses trait impulsivity related primarily to response inhibition and lack of premeditation, as a self-report index of cognitive control.

    Time frame: Baseline (Week 0), Week 3 Follow-Up, Week 10 Follow-Up

  3. Exit Interview

    A semi-structured exit interview will be administered to participants in the bipolar disorder (BD) cohort to assess acceptability of the combined tACS and cognitive training protocol and to inform future clinical implementation. The interview will assess participants' perceptions of each intervention component (tACS and cognitive training), including perceived benefits and concerns, suggestions for protocol modifications to enhance future benefit, and likelihood of recommending the intervention to other Veterans. All participants in the BD group will be approached for the exit interview, including those who do not complete all 10 intervention sessions, in order to capture factors contributing to low adherence; responses will be compared between active and sham tACS conditions to help distinguish concerns specific to the neuromodulation approach from those related to the cognitive training or overall study protocol.

    Time frame: Week 10 Follow-Up

06

Study locations

1 site
  • Minneapolis VA Health Care System, Minneapolis, MN
    Minneapolis, Minnesota 55417-2309, United States
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07845409
Lead sponsor
VA Office of Research and Development
Responsible party
Sponsor
First posted
Sep 28, 2026
Start date
Jun 1, 2027 (estimated)
Primary completion
Mar 31, 2031 (estimated)
Completion
Mar 31, 2031 (estimated)
Last update
Sep 28, 2026

Study contacts

Casey S Gilmore, PhD
Contact
Casey.Gilmore2@va.gov
(612) 725-2000 ext. 312051
Snezana Urosevic, PhD
Contact
Snezana.Urosevic@va.gov
(612) 467-3897
Casey S Gilmore, PhD
principal investigator · Minneapolis VA Health Care System, Minneapolis, MN

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
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