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Enrolling by invitationNCT07680959Updated Jul 9, 2026

Combining HD-tDCS and iTBS in Treating Negative Symptoms of Schizophrenia

An interventional study of active iTBS followed by active HD-tDCS and active iTBS followed by sham HD-tDCS in Negative Symptoms in Schizophrenia and Brain Stimulation Intervention, sponsored by Tri-Service General Hospital (TSGH). Enrolling by invitation at 1 site in Taiwan. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-07-09.

Sponsored by Tri-Service General Hospital (TSGH) · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 2 years 1 month after the study started (first participant enrolled May 2024, registered Jun 2026).
Phase
Not applicable
Study type
Interventional
Enrollment
100
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

Dysfunction of the dorsolateral prefrontal cortex (DLPFC) is central to the persistence of negative symptoms in schizophrenia. Both HD-tDCS and iTBS targeting the left DLPFC have shown therapeutic benefit. This trial will test the hypothesis that combining HD-tDCS with iTBS yields additive efficacy.

Read the detailed description

Dysfunction of the left dorsolateral prefrontal cortex (DLPFC) is central to the persistence of negative symptoms in schizophrenia, an area of unmet therapeutic need. High-definition transcranial direct current stimulation (HD-tDCS) and intermittent theta burst stimulation (iTBS), an optimized form of repetitive transcranial magnetic stimulation (rTMS), have each demonstrated efficacy in alleviating negative symptoms when applied to the left DLPFC. However, meta-analyses indicate only moderate effect sizes for these interventions individually. Evidence suggests that combining iTBS with tDCS may enhance cortical plasticity beyond either technique alone, warranting trials to assess additive efficacy. This double-blind, randomized, sham-controlled study will test the hypothesis that combined HD-tDCS and iTBS produce superior therapeutic benefit for negative symptoms in schizophrenia.

02

Conditions studied

  • Negative Symptoms in Schizophrenia
  • Brain Stimulation Intervention

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Keywords

  • HD-tDCS
  • iTBS
  • negative symptoms
  • schizophrenia
  • neuroimaging
03

In context

Schizophrenia

3,563 studies on the registry are indexed under Schizophrenia; 491 are open to participants now.

This study's planned enrollment of 100 is above the median of 71 across 2,944 interventional studies indexed under Schizophrenia.

Browse Schizophrenia studies →

Lead sponsor

Tri-Service General Hospital (TSGH) is the lead sponsor of 38 studies on the registry; 12 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Subjects diagnosed with schizophrenia or schizoaffective disorder;
  • With a clinical presentation characterized by predominant negative symptoms, as determined by psychiatric assessment and a score of at least 20 on the Negative Symptoms Subscale of the Positive and Negative Syndrome Scale (PANSS);
  • Stable positive and negative symptoms for at least 4 weeks, as documented in medical records and confirmed by clinical judgment and psychiatric interview;

Exclusion criteria

Exclusion Criteria:

  • Unstable medical conditions;
  • Current psychiatric comorbidity or active substance use disorder (except for tobacco use disorders);
  • for MRI, tDCS or rTMS;
  • Pregnancy or breastfeeding at the time of enrollment;
  • History of meningitis, encephalitis, seizures, intracranial neoplasms or surgery, severe head injury or cerebrovascular disease, or a family history of seizures;
  • rTMS or tDCS treatment within the past 6 months as well as a history of electroconvulsive therapy (ECT);
  • Any skin lesion at the stimulation sites;
  • Patients receiving medications that significantly change the seizure threshold;
  • A history of suicidal behavior within the past 6 months, or symptom worsening and emergence of suicidal ideation during the screening period.
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

DSM diagnostic criteria

The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

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Study design

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

Study arms

  • Experimental
    active iTBS followed by active HD-tDCS

    During the 3-week intervention phase, patients in this group will receive 2 sessions of active iTBS per working day for 2 weeks (totaling 20 sessions), followed by 2 sessions of active HD-tDCS per working day for 1 week (totaling 10 sessions).

    Device: active iTBS followed by active HD-tDCS

  • Experimental
    sham iTBS followed by active HD-tDCS

    During the 3-week intervention phase, patients in this group will receive 2 sessions of sham iTBS per working day for 2 weeks (totaling 20 sessions), followed by 2 sessions of active HD-tDCS per working day for 1 week (totaling 10 sessions).

    Device: sham iTBS followed by active HD-tDCS

  • Experimental
    active iTBS followed by sham HD-tDCS

    During the 3-week intervention phase, patients in this group will receive 2 sessions of active iTBS per working day for 2 weeks (totaling 20 sessions), followed by 2 sessions of sham HD-tDCS per working day for 1 week (totaling 10 sessions).

    Device: active iTBS followed by sham HD-tDCS

  • Sham comparator
    sham iTBS followed by sham HD-tDCS

    During the 3-week intervention phase, patients in this group will receive 2 sessions of sham iTBS per working day for 2 weeks (totaling 20 sessions), followed by 2 sessions of sham HD-tDCS per working day for 1 week (totaling 10 sessions).

    Device: sham iTBS followed by sham HD-tDCS

Interventions

  • Deviceactive iTBS followed by active HD-tDCS

    The active iTBS sessions will be delivered using the Magstim Rapid2 stimulator. The iTBS protocol consists of 3-pulse 50-Hz bursts given every 200 ms (at 5 Hz) for 2 s at 8-s intervals for 60 cycles. A 2-s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session. The intensity of stimulation will be set at 80% resting motor threshold (RMT). The target will be the left DLPFC with the coil centered at the MNI coordinate \[-38, 44, 26\] calculated from T1-weighted MRI. The active HD-tDCS will be applied by NeuroConn DC Stimulator Plus. The central anode will be placed over the International 10-20 electrode position F3 and the return peripheral electrodes placed at Fp1, Fz, C3 and F7. Stimulation session will be applied at an intensity of 2 mA, 8-sec fade in and 5-sec fade out, for 20 min. During each session, the subject has to perform a computerized working memory task (i.e., 2-back task). The two times daily sessions will be separated by at least 2 hours.

  • Deviceactive iTBS followed by sham HD-tDCS

    The active iTBS sessions will be delivered using the Magstim Rapid2 stimulator. The iTBS protocol consists of 3-pulse 50-Hz bursts given every 200 ms (at 5 Hz) for 2 s at 8-s intervals for 60 cycles. A 2-s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session. The intensity of stimulation will be set at 80% resting motor threshold (RMT). The target is the left DLPFC with the coil centered at the MNI coordinate \[-38, 44, 26\] calculated from T1-weighted MRI. In the sham HD-tDCS stimulation, short continuous currents without neuromodulatory effects will be applied to mimic real-stimulation sensations. Specifically, sham stimulation will deliver 40-sec, 2 mA normal-like stimulation, followed by a tiny current pulse (110 μA over 15 ms) for impedance control taking place every 550 ms for the remaining time. The other procedure is the same as the active HD-tDCS stimulation.

  • Devicesham iTBS followed by active HD-tDCS

    In the sham iTBS condition, the patients receive the same iTBS regimen and exact positioning of the coil but stimulations will be delivered using a commercial identical looking figure 8 sham coil (Magstim D70 Air film sham coil) that can produce a similar sound and sensation. In the active HD-tDCS condition, stimulation will be applied by a battery-operated device (NeuroConn DC Stimulator Plus) via 5 carbon rubber electrodes (1 cm radius, high-definition 4 × 1 rings configuration). To target the left DLPFC, the central electrode (anode) will be placed over International 10-20 electrode position F3, with return peripheral electrodes at Fp1, Fz, C3 and F7. Stimulation will be applied at an intensity of 2 milliamp (mA), 8-sec fade in and 5-sec fade out, for 20 min. During each session, the subject has to perform a computerized working memory task (i.e., 2-back task). The two times daily sessions will be separated by at least 2 hours.

  • Devicesham iTBS followed by sham HD-tDCS

    In the sham iTBS condition, patients receive the same iTBS regimen and exact positioning of the coil but stimulations will be delivered using a commercial identical looking figure 8 sham coil (Magstim D70 Air film sham coil) that can produce a similar sound and sensation. In the sham HD-tDCS condition, short continuous currents without neuromodulatory effects will be applied to mimic real-stimulation sensations. Specifically, sham stimulation will deliver 40-sec, 2 mA normal-like stimulation, followed by a tiny current pulse (110 μA over 15 ms) for impedance control taking place every 550 ms for the remaining time. The other procedure is the same as the active HD-tDCS stimulation.

06

What researchers measure

Primary outcomes

  1. The change in Positive and Negative Syndrome Scale (PANSS) negative subscale score

    PANSS is a clinician-administered rating scale to measure the severity of psychopathological symptoms of the patients with schizophrenia spectrum disorder. The patient is rated from 1 to 7 on 30 different symptom items. All items scores are summed up to yield a total PANSS score, which ranges from 30 to 210. A higher score indicates greater psychopathological symptom severity. PANSS negative subscale has 7 items with its score ranging from 7 to 49. The changes in the PANSS negative subscale score immediately after the 3-week intervention (primary endpoint), as well as at one-month and three-month follow-ups, will be collected as the primary outcome.

    Time frame: Fifteen weeks

Secondary outcomes

  1. The change in score of the Scale for the Assessment of Negative Symptoms (SANS)

    The Scale for the Assessment of Negative Symptoms (SANS) is used to assess negative symptoms in schizophrenia on a 25 item, 6-point scale. The SANS measures five domains of the negative symptoms including affective flattening or blunting, alogia, avolition - apathy, anhedonia - Asociality, Attention. In each domain, separate symptoms are rated from 0 (absent) to 5 (severe). A total SANS score ranges from 0 to 125. The changes in the SANS score immediately after the 3-week intervention, as well as at one-month and three-month follow-ups, will be collected as the secondary outcome.

    Time frame: Fifteen weeks

  2. The change in score of Calgary Depression Rating Scale for Schizophrenia (CDSS)

    The participants' depressive symptoms will be measured by Calgary Depression Rating Scale for Schizophrenia (CDSS). The changes in the CDSS score immediately after the 3-week intervention, as well as at one-month and three-month follow-ups, will be collected as the secondary outcome.

    Time frame: Fifteen weeks

  3. The change in the Personal and Social Performance scale (PSP) score

    PSP is a clinician-administered rating scale for measuring the psychosocial functioning of the patients with schizophrenia spectrum disorder. The PSP scale measures psychosocial functioning within four domains: socially useful activities, personal and social relationships, self-care, and disturbing and aggressive behavior.The patient is rated from 1 to 6 on each item of the four domains. A higher score indicates greater psychosocial functioning in any of the four domains. The final global score is defined according to a summary instruction table. This scale provides a single, overall rating from 1 to 100, where a higher score represents better personal and social function. The changes in the Personal and Social Performance scale (PSP) score immediately after the 3-week intervention, as well as at one-month and three-month follow-ups, will be collected as the secondary outcome.

    Time frame: Fifteen weeks

  4. The change in the score of the Beck Cognitive Insight Scale (BCIS)

    Cognitive insight was measured by the Taiwanese version of the Beck Cognitive Insight Scale (BCIS), a self-reported instrument comprising 15 items.The Taiwanese BCIS is composed of 2 subscales including reflective attitude (9 items) and certain attitude (6 items). We obtained a R-C (reflective attitude minus certain attitude) index of the Taiwanese BCIS, representing the measurement of cognitive insight by subtracting the score of the certain attitude subscale from that of the reflective attitude subscale. Lower R-C index scores indicate poorer cognitive insight. The changes in the score of the Beck Cognitive Insight Scale (BCIS) immediately after the 3-week intervention, as well as at one-month and three-month follow-ups, will be collected as the secondary outcome.

    Time frame: Fifteen weeks

  5. The change in the score of Schizophrenia Quality of Life Scale Revision Four (SQOLR4)

    The Chinese version of the Schizophrenia Quality of Life Scale Revision Four (SQOLR4) is a self-administered questionnaire of 33 items in two domains: psychosocial and vitality. All but four items are coded on a scale of 0-4 according to the frequency of occurrence during the previous 7 days (0 = always, 4 = never; the four exceptions are coded 0 = never, 4 = always). A higher score indicates higher health-related QoL. The changes in the score of Schizophrenia Quality of Life Scale Revision Four (SQOLR4) immediately after the 3-week intervention, as well as at one-month and three-month follow-ups, will be collected as the secondary outcome.

    Time frame: Fifteen weeks

  6. The changes in the results of the Tower of London Drexel University Test 2nd Edition

    The Tower of London Drexel University Test 2nd Edition is a neuropsychological test for the assessment of executive functioning specifically to detect deficits in planning, which may occur due to a variety of medical and neuropsychiatric conditions. The changes in the results of the Tower of London Drexel University Test 2nd Edition immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  7. The changes in the results of the Color Trails Test (CTT)

    The CTT, a culture-neutral version of the Trail Making Test, was selected to measure sustained visual attention. The CTT consists of two parts (CTT-1 and CTT-2). The CTT-1 requires participants to connect a series of numbered circles that are randomly printed on a sheet of paper. In the CTT-2, numbered circles of 1 to 25 are shown twice (printed in pink and in yellow) randomly on a sheet of paper. Participants are asked to connect the numbers from 1 to 25 alternating between the two colors. The changes in the results of the Color Trails Test (CTT) immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  8. The changes in the results of the Stroop Color Word Test (SCWT)

    Stroop Color Word Test (SCWT) will be administered to measure selective attention and cognitive flexibility. SCWT is composed of three parts, each lasting for 45 seconds. The changes in the results of the Stroop Color Word Test (SCWT) immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  9. The changes in indices of heart rate variability (HRV) derived from R-R intervals of ECG signals

    HRV indices represent autonomic functioning. ECG electrodes will be placed on bilateral arms just below the elbows, with a ground electrode placed just above the right wrist bone. Lead I electrocardiogram of each patient will be taken for 5 min after sitting and having a rest for 20 min in a soundproof, dim-lighted room with thermostatic control. The ECG signals will be acquired, stored, pre-processed according to the recommended procedures and processed by an HRV analyser. The time domain of HRV is obtained: Standard deviation of NN intervals (SDNN). Power spectrum of HRV is quantified into the standard frequency-domain measurements including low-frequency power (LF, 0.04-0.15 Hz), high-frequency power (HF, 0.15- 0.40 Hz). The changes in indices of heart rate variability (HRV) derived from R-R intervals of ECG signals immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  10. The changes in resting-state EEG features

    In a dimly lit, electrically shielded room, patients' electroencephalogram (EEG) will be recorded. Resting-state EEG will be collected with eye opened (5min) and closed (5min). Signals will be amplified by using EEG amplifiers and stored for offline analyses. The changes in resting-state EEG features (power, coherence, and microstates within different frequency bands including delta, theta, alpha and beta) immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  11. The changes in fNIRS features

    Functional near infrared spectroscopy (fNIRS) system is used to measure the relative changes in oxyhemoglobin (Hb) of the frontal regions. Resting-state fNIRS fo 180s and verbal fluency task (VFT)-based fNIRS for 160s will be collected in a quiet room. The changes in fNIRS features immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

  12. The changes in resting-state fMRI features

    Magnetic Resonance Imaging (MRI) scans will be performed on the hybrid 3.0T PET-MR imaging unit (GE Healthcare, Waukesha, WI). MRI scans will be carried out using the same imaging protocol, including T1-weighted images and resting-state functional MRI (rs-fMRIs).The changes in resting-state fMRI features immediately after the 3-week intervention will be collected as the secondary outcome.

    Time frame: Three weeks

07

Study locations

1 site
08

References and documents

Publications

  • Kishi T, Ikuta T, Sakuma K, Hamanaka S, Nishii Y, Hatano M, Kito S, Iwata N. Theta Burst Stimulation Protocols for Schizophrenia: A Systematic Review and Network Meta-Analysis. JAMA Netw Open. 2024 Oct 1;7(10):e2441159. doi: 10.1001/jamanetworkopen.2024.41159. PubMed 39446321 ↗
  • Tong S, Chen S, Chen J, Tong Z, Li W, Liu S, Shi H, Yao L, Zhang C, Zhang X. Efficacy and long-term effects of intermittent theta burst stimulation on negative symptoms in schizophrenia: a systematic review and meta-analysis. Brain Commun. 2026 Jan 29;8(1):fcag027. doi: 10.1093/braincomms/fcag027. eCollection 2026. PubMed 41704822 ↗
  • Gupta R, Sharma A, Goyal N. Breaking the Negative Symptom Barrier: A Novel Neuromodulation Strategy Using HD-tDCS Primed iTBS in Schizophrenia. J ECT. 2026 Jan 20. doi: 10.1097/YCT.0000000000001224. Online ahead of print. PubMed 41575458 ↗
  • Ma CC, Lin YY, Chung YA, Park SY, Huang CC, Chang WC, Chang HA. The two-back task leads to activity in the left dorsolateral prefrontal cortex in schizophrenia patients with predominant negative symptoms: a fNIRS study and its implication for tDCS. Exp Brain Res. 2024 Mar;242(3):585-597. doi: 10.1007/s00221-023-06769-5. Epub 2024 Jan 16. PubMed 38227007 ↗
  • Yeh TC, Lin YY, Tzeng NS, Kao YC, Chung YA, Chang CC, Fang HW, Chang HA. Effects of online high-definition transcranial direct current stimulation over left dorsolateral prefrontal cortex on predominant negative symptoms and EEG functional connectivity in patients with schizophrenia: a randomized, double-blind, controlled trial. Psychiatry Clin Neurosci. 2025 Jan;79(1):2-11. doi: 10.1111/pcn.13745. Epub 2024 Sep 24. PubMed 39317963 ↗
  • Lin CE, Chen LF, Sack AT, Chang HA. Task-based fNIRS biomarkers of HD-tDCS treatment for negative symptoms in schizophrenia. Schizophr Res. 2026 Aug;294:35-43. doi: 10.1016/j.schres.2026.04.010. Epub 2026 Apr 17. PubMed 42000633 ↗

Individual participant data

Plan to share: No — Individual participant data (IPD) will not be shared, as required by the local ethics committee to protect patient privacy.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started May 2024 (actual). Primary completion is estimated for Dec 2027, 43 months after the start.

Of 753 non-industry interventional studies with no phase under Schizophrenia, half reached primary completion within 33 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 56. This study's planned 43 months is above that.

Counting every sponsor, half of 766 studies reached it within 32 months; a quarter within 16 and three quarters within 56.

How these figures are worked out, and which studies are left out of them.

Registered
Jun 26, 2026
First posted
Jul 2, 2026
StartActual
May 6, 2024
Primary completionEst.
Dec 31, 2027
CompletionEst.
Mar 1, 2028
Last update
Jul 9, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jul 9, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07680959
Lead sponsor
Tri-Service General Hospital (TSGH)
Collaborators
National Science and Technology Council, Taiwan
Responsible party
Hsin-An Chang, MD (Attending psychiatrist, Tri-Service General Hospital (TSGH)) — Principal investigator
First posted
Jul 2, 2026
Start date
May 6, 2024
Primary completion
Dec 31, 2027 (estimated)
Completion
Mar 1, 2028 (estimated)
Last update
Jul 9, 2026

Study contacts

Hsin-An Chang, M.D.
principal investigator · Tri-Service General Hospital (TSGH)

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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