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Depression MinorNCT04031105

Probing Homeostatic Plasticity With Priming Theta-burst Stimulation of the Dorsolateral Prefrontal Cortex

A study testing Theta-burst stimulation (TBS) in people with Depression Minor, run by Dr Georg Kranz at 1 site in Hong Kong.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Priming stimulation is a highly promising tool to boost the beneficial effects of therapeutic repetitive transcranial magnetic stimulation (rTMS) in psychiatry. The potentiating effects of priming stimulation, however, depend on the time interval between the priming and the test stimulation. Read more about this study

Who is it for?
Ages 18 to 35 yearsHealthy volunteers can take part
Conditions the study is for
Depression Minor
What is being tested?
Theta-burst stimulation (TBS)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
160 participants
Where
1 siteHong Kong
Study dates
23 May 2021to 16 Jan 2024
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 35 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • age 18-35
  • education level of primary six or above
  • right-handedness
  • normal or corrected-to-normal vision
  • being able to understand the verbal instructions
  • willingness to sign the informed consent form

Who cannot join

  • a history of seizures
  • current or past psychiatric disorders
  • current or past severe internal or neurological illness
  • ferromagnetic implants <20cm from the head, cardiac pacemaker, deep brain stimulation and other common TMS exclusion criteria
  • history of substance dependence or abuse within the last 3 months
  • intake of any medication known to affect the excitation threshold (i.e., benzodiazepines, anticonvulsants).

Trial locations and contacts

1 site in 1 country.

Hong Kong1 site
  • The Hong Kong Polytechnic University

    Hong Kong

Other trials in Hong Kong

About this study

Priming stimulation is a highly promising tool to boost the beneficial effects of therapeutic repetitive transcranial magnetic stimulation (rTMS) in psychiatry. The potentiating effects of priming stimulation, however, depend on the time interval between the priming and the test stimulation. Although it is known that too short and too long intervals have no effects, systematic studies that identify the time needed to maximize efficacy have not yet been done. Thus, there is a need for studies to investigate the effects of priming stimulation in order to fully utilize the potential benefits and advantages of this promising new rTMS protocol. This study will systematically investigate the neuromodulatory process underlying priming stimulation to enhance metaplasticity in the left dorsolateral prefrontal cortex (DLPFC) - one of the main targets for therapeutic rTMS - in individuals with subclinical depression.

The brain is a highly plastic organ and its activity can be influenced using rTMS. At the same time, the brain also has a mechanism - called homeostatic metaplasticity - which counteracts extreme plastic changes. Homeostatic metaplasticity therefore can limit the beneficial effects of brain stimulation interventions. However, priming stimulation protocols that include both a priming and a test stimulation session may utilize homeostatic metaplasticity to increase the beneficial effects of brain stimulation, although the optimal treatment parameters for priming are not known. Moreover, little is known about homeostatic metaplasticity in the DLPFC, an area that is particularly relevant for psychiatric conditions given its role in the top-down control of emotions. Here, the investigators will systematically study metaplasticity using priming theta-burst stimulation (TBS), a potent form of rTMS in the left DLPFC. Changes in blood oxygenation that signal brain activity changes will be assessed using functional near-infrared spectroscopy (fNIRS) at rest and during engagement in several cognitive tasks. The findings from this study will (1) elucidate the optimal time interval between priming and test stimulation; (2) elucidate the influence of priming TBS on emotion discrimination as well as executive function and its underlying brain activity in subclinical depression; and (3) validate homeostatic metaplasticity in the left DLPFC.

Read the detailed description

No detailed description

Being tested
Theta-burst stimulation (TBS)

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Theta-burst stimulation (TBS)Device

    Also called Transcranial Magnetic Stimulation

    intermittent (iTBS) and continuous (cTBS) will be applied at an intensity of 70% or 100%* resting motor threshold (RMT) on the dorsolateral prefrontal cortex, position F3 (EEG 10-20 international system)

    *The optimal %RMT will be evaluated in a pilot study before commencement of the main study

Study groups in NCT04031105
Study groupRoleWhat they receive
Condition 1ExperimentalPriming sham TBS, followed by iTBS after an inter-stimulation-interval (ISI) of 0 minutes
Receives: Device: Theta-burst stimulation (TBS)
Condition 2ExperimentalPriming cTBS, followed by iTBS after an ISI of 0 minutes
Receives: Device: Theta-burst stimulation (TBS)
Condition 3ExperimentalPriming cTBS, followed by iTBS after an ISI of 10 minutes
Receives: Device: Theta-burst stimulation (TBS)
Condition 4ExperimentalPriming cTBS, followed by iTBS after an ISI of 20 minutes
Receives: Device: Theta-burst stimulation (TBS)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in hemoglobin concentrations (Hb) during rest

    Oxy- and deoxy-hemoglobin (HbO, HHb) and total Hb will be acquired using functional near-infrared spectroscopy (fNIRS)

    Measured: Change from baseline Hb at 15 minutes post-stimulation

  2. Change in hemoglobin concentrations (Hb) while participants perform an emotion stroop task and verbal fluency task

    Oxy- and deoxy-hemoglobin (HbO, HHb) and total Hb will be acquired using functional near-infrared spectroscopy (fNIRS)

    Measured: Change from baseline Hb at 15 minutes after stimulation

Secondary outcomes (3)
  1. Change in reaction time during emotion stroop task

    Before and after stimulation, participants will perform a emotion stroop task. Participants are asked to indicate by button press in which color (red, yellow, blue, green) the word is presented on a computer screen,("c" for red, "v" for yellow, "n" for blue, "m" for green) . The total number and the reaction time of correct response will be recorded.

    Measured: Change from baseline reaction times at 15 minutes after stimulation

  2. Change in the number of correctly responded colored words in the emotional Stroop task and correctly generated words in the verbal fluency task.

    Before and after stimulation, participants will perform an emotional Stroop task as described in Outcome 3. In addition, participants will also perform a verbal fluency task, In this task, participants are required to speak out as many unique words as possible during the word generation blocks, according to a given category (for example, name animals). The category will be presented at the center of the screen. The total number of correct answers will be recorded

    Measured: Change from baseline score at 15 minutes after stimulation

  3. Change in the number of correctly recognized emotion

    In addition, participants will perform an emotion-recognition accuracy task. They will be presented with 64 facial stimuli, consisting of sets of 16 sad, happy, fearful and neutral faces, in a randomized order. Faces will be presented for a maximum of 6s. Participants have to indicate the depicted emotion by button press (choice between 4 answers) within the presentation period.

    Measured: Change from baseline score at 15 minutes after stimulation

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Jul 2019
  2. Study start23 May 2021
  3. Primary completion16 Jan 2024
  4. Study completion16 Jan 2024

Resources

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
Parallel groups
Model description
Randomized, single blind, parallel group experiment
Masking
Single blind
Who is masked
Participant
Enrolment
160 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04031105
Sponsor's protocol ID
PolyU 251002/19M
Status last verified
Sep 2024
First submitted
17 Jul 2019
Last updated
19 Sep 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Sharing upon request

Questions about this trial

What is this clinical trial studying?

A study testing Theta-burst stimulation (TBS) in people with Depression Minor, run by Dr Georg Kranz at 1 site in Hong Kong.

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 6 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 19 Sep 2024. 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 Hong Kong. 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. 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?

Change in hemoglobin concentrations (Hb) during rest (time frame: Change from baseline Hb at 15 minutes post-stimulation). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 19 Sep 2024.

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