Healthy Control SubjectsSTEP-MCNCT06735794
Impact of Spaced iTBS on Plasticity in the Motor Cortex
A study testing Compressed iTBS and Spaced iTBS in people with Healthy Control Subjects, run by Centre for Addiction and Mental Health at 1 site in Canada.
Trial summary
The goal of this clinical trial is to explore the effects of non-invasive brain stimulation protocols using intermittent theta-burst stimulation (iTBS) on brain plasticity in healthy, right-handed individuals aged 18 to 50 years. Brain plasticity is the brain's ability to change through growth or reorganization. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Control Subjects
- What is being tested?
- Compressed iTBS and Spaced iTBS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 29 participants
- Where
- 1 siteCanada
- Study dates
- 13 Nov 2024to 1 Feb 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 18 years or above, and less than 51 years.
- Right handedness, assessed using the Edinburgh Handedness Inventory (EHI).
- Sufficiently proficient in English to complete the required study assessments, as per investigator judgement.
- Willingness and capacity to provide informed consent.
- Willingness to comply with all study procedures.
Who cannot join
- Age 17 years or less, or greater than 51 years, as brain plasticity is known to be affected by age.
- Current use of any psychotropic medications (e.g. anti-depressants, anti-convulsants, anti-psychotics, etc.).
- Contraindications to transcranial magnetic stimulation (TMS), as per investigator judgment.
- Lifetime history of any Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnosis, assessed using the Structured Clinical Interview for DSM-5 (SCID-5), except simple phobias.
- Left handed or ambidextrous, assessed using the EHI, to minimize the heterogeneity in cortical excitability and plasticity.
- Self-reported history of seizures and/or other major neurological conditions, as per investigator judgement, due to the risk of seizures associated with TMS in individuals with a heightened risk.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Spaced iTBS: Effects on Plasticity in the Motor Cortex
The goal of this clinical trial is to explore the effects of non-invasive brain stimulation protocols using intermittent theta-burst stimulation (iTBS) on brain plasticity in healthy, right-handed individuals aged 18 to 50 years. Brain plasticity is the brain's ability to change through growth or reorganization. iTBS is a form of transcranial magnetic stimulation (TMS), where magnetic pulses are applied to the scalp using a coil. These pulses pass through the scalp, and can alter brain activity in the area underneath the coil. Based on previous research conducted in animals and humans, researchers believe that iTBS can strengthen the connections between cells in the brain, leading to improved brain plasticity.
This trial will compare the effects of the compressed iTBS (iTBS-c) protocol, which is commonly used to treat depression, and the spaced iTBS (iTBS-s) protocol. Researchers want to find out which protocol is better able to produce changes in brain plasticity. Sham iTBS (iTBS-sh) will be used as a control to make the results of the study more reliable.
Read more
Participants will complete 5 study visits within the span of 3 months, including:
- Screening assessments to determine eligibility (Visit 1);
- Calibration iTBS session (Visit 2) to assess tolerability of brain stimulation;
- Three experimental iTBS sessions (iTBS-s, iTBS-c, and iTBS-sh) in a randomized order (Visits 3-5), each separated by at least 72 hours. During each session, the study team will stimulate the motor cortex and record the muscle activity of your hand to measure changes in brain plasticity.
Read the detailed description
Major Depressive Disorder (MDD) is a mental illness affecting millions of individuals worldwide and in Canada, and is a leading cause of morbidity, mortality, and disability. While antidepressant medications are effective in treating MDD, their efficacy is moderate and systemic side-effects persist, such as sexual dysfunction, drowsiness, weight gain, and dry mouth. Thus, more effective treatments are needed for MDD.
Neuroimaging techniques have implicated the dysregulation of brain plasticity in depression. In particular, long-term potentiation (LTP)-like activity in the dorsolateral prefrontal cortex (DLPFC) and the motor cortex is known to be impaired in MDD. As such, transcranial magnetic stimulation (TMS)-based interventions, which aim to modify underlying cortical activity, are now established treatments of depression. Intermittent theta-burst stimulation (iTBS), a novel form of repetitive TMS approved by the US Food and Drug Administration (FDA) for the treatment of depression, delivers intermittent, high-frequency theta bursts. It has been demonstrated to induce sustained plasticity in the DLPFC and the motor cortex. Although iTBS is approved for the treatment of depression, response and remission rates for MDD are still relatively low.
Based on promising research conducted in the hippocampus of rodents, the investigators believe that modifying some parameters of the iTBS protocol may be more effective in inducing plasticity than the currently used iTBS protocol. Thus, in this trial researchers aim to optimize iTBS and its effects on cortical plasticity as a first step towards optimizing it for the treatment of depression.
The primary and secondary objectives and hypotheses of the study are as follows:
Objective 1: To compare the effect of compressed iTBS (iTBS-c) to spaced iTBS (iTBS-s) on LTP-like activity (referred to hereafter as iTBS-LTP) as measured using motor evoked potentials (MEPs) recorded from the right abductor pollicis brevis (APB), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) muscles.
Hypothesis 1: iTBS-s will elicit larger iTBS-LTP post-iTBS as compared to iTBS-c.
Objective 2: To compare the effect of iTBS-c and iTBS-s on iTBS-LTP relative to iTBS-sh.
Hypothesis 2: iTBS-c and iTBS-s will elicit larger iTBS-LTP post-iTBS as compared to iTBS-sh.
- Conditions
- Healthy Control Subjects
- Being tested
- Compressed iTBS, Spaced iTBS, Sham iTBS
- Keywords
- TMS, TBS, Brain stimulation, Healthy, Control, Healthy individuals, Transcranial Magnetic Stimulation, Intermittent Theta-Burst Stimulation, Motor Cortex, Neuroplasticity, Brain plasticity, Cortical plasticity, iTBS, iTBS-c, iTBS-s, iTBS-sh, Spaced iTBS, Compressed iTBS, Sham iTBS, LTP
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Compressed iTBSDevice
Also called iTBS-c
Intermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity.
During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-c (active comparator), which will be delivered unilaterally to the left motor cortex. Following iTBS-c, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation.
The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention.
Spaced iTBSDevice
Also called iTBS-s
Intermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity.
During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-s (experimental study intervention), which will be delivered unilaterally to the left motor cortex. Following iTBS-s, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation.
The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention.
Sham iTBSDevice
Also called iTBS-sh
Intermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity.
During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-sh (sham comparator), which will be delivered unilaterally to the left motor cortex. Following iTBS-sh, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation.
The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention.
| Study group | Role | What they receive |
|---|---|---|
| Compressed iTBS | Active comparator | After completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-c condition in a randomized order during Visits 3 to 5. iTBS-c is the active comparator. Receives: Device: Compressed iTBS |
| Spaced iTBS | Experimental | After completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-s condition in a randomized order during Visits 3 to 5. iTBS-s is the experimental study intervention. Receives: Device: Spaced iTBS |
| Sham iTBS | Sham comparator | After completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-sh condition in a randomized order during Visits 3 to 5. iTBS-sh is the sham comparator. Receives: Device: Sham iTBS |
What is being measured
The primary outcome is the main question the study is designed to answer.
iTBS-LTP
The primary outcome measure is iTBS-induced LTP (iTBS-LTP), which will be calculated at each post-iTBS time points (Post-0, Post-15, Post-30, Post-45 and Post-60).
At each time point, the mean or median MEP amplitude will be divided by the mean or median MEP amplitude across the two pre-iTBS TMS measurements (Pre-30 and Pre-15) for the corresponding iTBS condition. This will be repeated for all three iTBS conditions to generate iTBS-LTP values at the five post-iTBS time points. Larger iTBS-LTP values are indicative of stronger plasticity following the intervention.
This will address hypothesis 1, which examines whether iTBS-s induces stronger iTBS-LTP compared to iTBS-c, and hypothesis 2, which evaluates whether iTBS-s and iTBS-c induce stronger iTBS-LTP compared to iTBS-sh.
Measured: Up to 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2024
- Study start13 Nov 2024
- Primary completion1 Feb 2026
- Study completion1 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (9)Papers the sponsor has linked to this study.
- Other trials for Healthy Control SubjectsStudies of the same condition, open and under way.
- More trials run by Centre for Addiction and Mental HealthThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study will employ a randomized, single-blind cross-over design with three experimental iTBS conditions (iTBS-c, iTBS-s, and iTBS-sh).
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 29 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre for Addiction and Mental Health
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06735794
- Sponsor's protocol ID
- 2023/218
- Acronym
- STEP-MC
- Status last verified
- Oct 2024
- First submitted
- 22 Nov 2024
- Last updated
- 4 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Berlim MT, McGirr A, Rodrigues Dos Santos N, Tremblay S, Martins R. Efficacy of theta burst stimulation (TBS) for major depression: An exploratory meta-analysis of randomized and sham-controlled trials. J Psychiatr Res. 2017 Jul;90:102-109. doi: 10.1016/j.jpsychires.2017.02.015. Epub 2017 Feb 21.
PubMed 28254709Chung SW, Hoy KE, Fitzgerald PB. Theta-burst stimulation: a new form of TMS treatment for depression? Depress Anxiety. 2015 Mar;32(3):182-92. doi: 10.1002/da.22335. Epub 2014 Nov 28.
PubMed 25450537Höflich G, Kasper S, Hufnagel A, Ruhrmann S, Möller HJ. Application of transcranial magnetic stimulation in treatment of drug-resistant major depression-a report of two cases. Human Psychopharmacology: Clinical and Experimental. 1993;8(5):361-365.
George MS, Wassermann EM, Williams WA, Callahan A, Ketter TA, Basser P, Hallett M, Post RM. Daily repetitive transcranial magnetic stimulation (rTMS) improves mood in depression. Neuroreport. 1995 Oct 2;6(14):1853-6. doi: 10.1097/00001756-199510020-00008.
PubMed 8547583George MS, Lisanby SH, Avery D, McDonald WM, Durkalski V, Pavlicova M, Anderson B, Nahas Z, Bulow P, Zarkowski P, Holtzheimer PE 3rd, Schwartz T, Sackeim HA. Daily left prefrontal transcranial magnetic stimulation therapy for major depressive disorder: a sham-controlled randomized trial. Arch Gen Psychiatry. 2010 May;67(5):507-16. doi: 10.1001/archgenpsychiatry.2010.46.
PubMed 20439832Cantone M, Bramanti A, Lanza G, Pennisi M, Bramanti P, Pennisi G, Bella R. Cortical Plasticity in Depression. ASN Neuro. 2017 May-Jun;9(3):1759091417711512. doi: 10.1177/1759091417711512.
PubMed 28629225Vignaud P, Damasceno C, Poulet E, Brunelin J. Impaired Modulation of Corticospinal Excitability in Drug-Free Patients With Major Depressive Disorder: A Theta-Burst Stimulation Study. Front Hum Neurosci. 2019 Feb 26;13:72. doi: 10.3389/fnhum.2019.00072. eCollection 2019.
PubMed 30863297Liu W, Ge T, Leng Y, Pan Z, Fan J, Yang W, Cui R. The Role of Neural Plasticity in Depression: From Hippocampus to Prefrontal Cortex. Neural Plast. 2017;2017:6871089. doi: 10.1155/2017/6871089. Epub 2017 Jan 26.
PubMed 28246558Duman RS. Pathophysiology of depression: the concept of synaptic plasticity. Eur Psychiatry. 2002 Jul;17 Suppl 3:306-10. doi: 10.1016/s0924-9338(02)00654-5.
PubMed 15177086
Study at a glance
From the registry record, last updated by the sponsor on 4 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Spaced iTBS: Effects on Plasticity in the Motor Cortex
- ClinicalTrials.gov ID
- NCT06735794
- Acronym / sponsor ID
- STEP-MC / 2023/218
- Conditions
- Healthy Control Subjects
- Keywords
- TMS, TBS, Brain stimulation, Healthy, Control, Healthy individuals, Transcranial Magnetic Stimulation, Intermittent Theta-Burst Stimulation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 29 participants (actual)
- Lead sponsor
- Centre for Addiction and Mental HealthUniversity, hospital or other
- Study start
- 13 Nov 2024 (actual)
- Primary completion
- 1 Feb 2026 (actual)
- Study completion
- 1 Feb 2026 (actual)
- First posted
- 16 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to explore the effects of non-invasive brain stimulation protocols using intermittent theta-burst stimulation (iTBS) on brain plasticity in healthy, right-handed individuals aged 18 to 50 years. Brain plasticity is the brain's ability to change through growth or reorganization. iTBS is a form of transcranial magnetic stimulation (TMS), where magnetic pulses are applied to the scalp using a coil. These pulses pass through the scalp, and can alter brain activity in the area underneath the coil. Based on previous research conducted in animals and humans, researchers believe that iTBS can strengthen the connections between cells in the brain, leading to improved brain plasticity.
This trial will compare the effects of the compressed iTBS (iTBS-c) protocol, which is commonly used to treat depression, and the spaced iTBS (iTBS-s) protocol. Researchers want to find out which protocol is better able to produce changes in brain plasticity. Sham iTBS (iTBS-sh) will be used as a control to make the results of the study more reliable.
Participants will complete 5 study visits within the span of 3 months, including:
- Screening assessments to determine eligibility (Visit 1);
- Calibration iTBS session (Visit 2) to assess tolerability of brain stimulation;
- Three experimental iTBS sessions (iTBS-s, iTBS-c, and iTBS-sh) in a randomized order (Visits 3-5), each separated by at least 72 hours. During each session, the study team will stimulate the motor cortex and record the muscle activity of your hand to measure changes in brain plasticity.
Detailed description
Major Depressive Disorder (MDD) is a mental illness affecting millions of individuals worldwide and in Canada, and is a leading cause of morbidity, mortality, and disability. While antidepressant medications are effective in treating MDD, their efficacy is moderate and systemic side-effects persist, such as sexual dysfunction, drowsiness, weight gain, and dry mouth. Thus, more effective treatments are needed for MDD.
Neuroimaging techniques have implicated the dysregulation of brain plasticity in depression. In particular, long-term potentiation (LTP)-like activity in the dorsolateral prefrontal cortex (DLPFC) and the motor cortex is known to be impaired in MDD. As such, transcranial magnetic stimulation (TMS)-based interventions, which aim to modify underlying cortical activity, are now established treatments of depression. Intermittent theta-burst stimulation (iTBS), a novel form of repetitive TMS approved by the US Food and Drug Administration (FDA) for the treatment of depression, delivers intermittent, high-frequency theta bursts. It has been demonstrated to induce sustained plasticity in the DLPFC and the motor cortex. Although iTBS is approved for the treatment of depression, response and remission rates for MDD are still relatively low.
Based on promising research conducted in the hippocampus of rodents, the investigators believe that modifying some parameters of the iTBS protocol may be more effective in inducing plasticity than the currently used iTBS protocol. Thus, in this trial researchers aim to optimize iTBS and its effects on cortical plasticity as a first step towards optimizing it for the treatment of depression.
The primary and secondary objectives and hypotheses of the study are as follows:
Objective 1: To compare the effect of compressed iTBS (iTBS-c) to spaced iTBS (iTBS-s) on LTP-like activity (referred to hereafter as iTBS-LTP) as measured using motor evoked potentials (MEPs) recorded from the right abductor pollicis brevis (APB), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) muscles.
Hypothesis 1: iTBS-s will elicit larger iTBS-LTP post-iTBS as compared to iTBS-c.
Objective 2: To compare the effect of iTBS-c and iTBS-s on iTBS-LTP relative to iTBS-sh.
Hypothesis 2: iTBS-c and iTBS-s will elicit larger iTBS-LTP post-iTBS as compared to iTBS-sh.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- This study will employ a randomized, single-blind cross-over design with three experimental iTBS conditions (iTBS-c, iTBS-s, and iTBS-sh).
| Arm | Type | Receives |
|---|---|---|
| Compressed iTBS | Active comparator | Device: Compressed iTBSAfter completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-c condition in a randomized order during Visits 3 to 5. iTBS-c is the active comparator. |
| Spaced iTBS | Experimental | Device: Spaced iTBSAfter completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-s condition in a randomized order during Visits 3 to 5. iTBS-s is the experimental study intervention. |
| Sham iTBS | Sham comparator | Device: Sham iTBSAfter completing Visits 1-2 (Screening and Calibration), participants will undergo the iTBS-sh condition in a randomized order during Visits 3 to 5. iTBS-sh is the sham comparator. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Age 18 years or above, and less than 51 years.
- Right handedness, assessed using the Edinburgh Handedness Inventory (EHI).
- Sufficiently proficient in English to complete the required study assessments, as per investigator judgement.
- Willingness and capacity to provide informed consent.
- Willingness to comply with all study procedures.
Key exclusion criteria (6 listed)
- Age 17 years or less, or greater than 51 years, as brain plasticity is known to be affected by age.
- Current use of any psychotropic medications (e.g. anti-depressants, anti-convulsants, anti-psychotics, etc.).
- Contraindications to transcranial magnetic stimulation (TMS), as per investigator judgment.
- Lifetime history of any Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnosis, assessed using the Structured Clinical Interview for DSM-5 (SCID-5), except simple phobias.
- Left handed or ambidextrous, assessed using the EHI, to minimize the heterogeneity in cortical excitability and plasticity.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Compressed iTBSAlso: iTBS-cIntermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity. During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-c (active comparator), which will be delivered unilaterally to the left motor cortex. Following iTBS-c, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation. The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention. | Device | Compressed iTBS |
| Spaced iTBSAlso: iTBS-sIntermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity. During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-s (experimental study intervention), which will be delivered unilaterally to the left motor cortex. Following iTBS-s, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation. The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention. | Device | Spaced iTBS |
| Sham iTBSAlso: iTBS-shIntermittent Theta-Burst Stimulation (iTBS) is a form of non-invasive brain stimulation that uses magnetic pulses applied to the scalp using a coil. iTBS will be used to stimulate the left motor cortex to enhance long-term potentiation (LTP)-like activity, a physiological mechanism associated with brain plasticity. During the intervention, the study team will conduct two pre-iTBS TMS measurements (Pre-30 and Pre-15). Participants will then complete iTBS-sh (sham comparator), which will be delivered unilaterally to the left motor cortex. Following iTBS-sh, five post-iTBS TMS measurements (Post-0, 15, 30, 45, and 60) will be obtained. Motor evoked potentials (MEPs) will be recorded from the right APB, ADM, and FDI muscles to assess the effects of the stimulation. The MCF-B65, MCF-P-B65, and/or Cool-B65 A/P TMS coils will be used, alongside the MagPro R30 or the MagPro X100 TMS stimulators to deliver the intervention. | Device | Sham iTBS |
Primary outcome
iTBS-LTP
Time frame: Up to 3 months
The primary outcome measure is iTBS-induced LTP (iTBS-LTP), which will be calculated at each post-iTBS time points (Post-0, Post-15, Post-30, Post-45 and Post-60). At each time point, the mean or median MEP amplitude will be divided by the mean or median MEP amplitude across the two pre-iTBS TMS measurements (Pre-30 and Pre-15) for the corresponding iTBS condition. This will be repeated for all three iTBS conditions to generate iTBS-LTP values at the five post-iTBS time points. Larger iTBS-LTP values are indicative of stronger plasticity following the intervention. This will address hypothesis 1, which examines whether iTBS-s induces stronger iTBS-LTP compared to iTBS-c, and hypothesis 2, which evaluates whether iTBS-s and iTBS-c induce stronger iTBS-LTP compared to iTBS-sh.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Feb 2026.
- Results publication: PubMed 28254709Berlim MT, McGirr A, Rodrigues Dos Santos N, Tremblay S, Martins R. Efficacy of theta burst stimulation (TBS) for major depression: An exploratory meta-analysis of randomized and sham-controlled trials. J Psychiatr Res. 2017 Jul;90:102-109. doi: 10.1016/j.jpsychires.2017.02.015. Epub 2017 Feb 21.
- Results publication: PubMed 25450537Chung SW, Hoy KE, Fitzgerald PB. Theta-burst stimulation: a new form of TMS treatment for depression? Depress Anxiety. 2015 Mar;32(3):182-92. doi: 10.1002/da.22335. Epub 2014 Nov 28.
- Results publicationHöflich G, Kasper S, Hufnagel A, Ruhrmann S, Möller HJ. Application of transcranial magnetic stimulation in treatment of drug-resistant major depression-a report of two cases. Human Psychopharmacology: Clinical and Experimental. 1993;8(5):361-365.
- Results publication: PubMed 8547583George MS, Wassermann EM, Williams WA, Callahan A, Ketter TA, Basser P, Hallett M, Post RM. Daily repetitive transcranial magnetic stimulation (rTMS) improves mood in depression. Neuroreport. 1995 Oct 2;6(14):1853-6. doi: 10.1097/00001756-199510020-00008.
- Results publication: PubMed 20439832George MS, Lisanby SH, Avery D, McDonald WM, Durkalski V, Pavlicova M, Anderson B, Nahas Z, Bulow P, Zarkowski P, Holtzheimer PE 3rd, Schwartz T, Sackeim HA. Daily left prefrontal transcranial magnetic stimulation therapy for major depressive disorder: a sham-controlled randomized trial. Arch Gen Psychiatry. 2010 May;67(5):507-16. doi: 10.1001/archgenpsychiatry.2010.46.
- Results publication: PubMed 28629225Cantone M, Bramanti A, Lanza G, Pennisi M, Bramanti P, Pennisi G, Bella R. Cortical Plasticity in Depression. ASN Neuro. 2017 May-Jun;9(3):1759091417711512. doi: 10.1177/1759091417711512.
- Results publication: PubMed 30863297Vignaud P, Damasceno C, Poulet E, Brunelin J. Impaired Modulation of Corticospinal Excitability in Drug-Free Patients With Major Depressive Disorder: A Theta-Burst Stimulation Study. Front Hum Neurosci. 2019 Feb 26;13:72. doi: 10.3389/fnhum.2019.00072. eCollection 2019.
- Results publication: PubMed 28246558Liu W, Ge T, Leng Y, Pan Z, Fan J, Yang W, Cui R. The Role of Neural Plasticity in Depression: From Hippocampus to Prefrontal Cortex. Neural Plast. 2017;2017:6871089. doi: 10.1155/2017/6871089. Epub 2017 Jan 26.
- Results publication: PubMed 15177086Duman RS. Pathophysiology of depression: the concept of synaptic plasticity. Eur Psychiatry. 2002 Jul;17 Suppl 3:306-10. doi: 10.1016/s0924-9338(02)00654-5.
- Individual participant dataSharing planned: No
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PET Imaging of the sigma1 Receptor in Healthy Adults
Healthy Control Subjects
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Compressed iTBS and Spaced iTBS in people with Healthy Control Subjects, run by Centre for Addiction and Mental Health at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
iTBS-LTP (time frame: Up to 3 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06735794, which also lists 9 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Feb 2026.