Attention Deficit Disorder With Hyperactivity (ADHD)NCT07145593
Gamma tACS in Attention-Deficit/Hyperactivity Disorder
A study testing Application tACS- 80 Hz, Application tACS -40 Hz and Application TACS - (6-80 Hz) in people with Attention Deficit Disorder With Hyperactivity (ADHD), run by Medipol University at 1 site in Turkey (Türkiye).
Trial summary
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by symptoms of inattention, impulsivity, and hyperactivity. These symptoms are often associated with impairments in executive functions and working memory, which are essential for goal-directed behavior and cognitive… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Attention Deficit Disorder With Hyperactivity (ADHD)
- What is being tested?
- Application tACS- 80 Hz, Application tACS -40 Hz and Application TACS - (6-80 Hz)
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Oct 2025to 30 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Being between 18 and 40 years of age
- Receiving an ADHD diagnosis
- Scoring above 25 on the Montreal Cognitive Assessment (MoCA)
- Being right-handed
Who cannot join
- Use of medications with sedative or stimulant effects
- Presence of metal brain implants or a pacemaker
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Gamma Transcranial Alternating Current Stimulation in Attention Deficit Hyperactivity Disorder
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by symptoms of inattention, impulsivity, and hyperactivity. These symptoms are often associated with impairments in executive functions and working memory, which are essential for goal-directed behavior and cognitive control. Deficits in these domains can significantly hinder individuals' academic, social, and daily functioning. Gamma oscillations (30-80 Hz) play a crucial role in cognitive integration, attention, and memory processes, and are thought to emerge from the balance between excitatory and inhibitory neuronal activity.
Transcranial Alternating Current Stimulation (tACS) is a non-invasive brain stimulation technique that modulates neuronal activity through rhythmic electrical currents. Recent studies suggest that gamma-frequency tACS applied to the prefrontal cortex can enhance cognitive performance and attentional processes. In individuals with ADHD, disrupted gamma connectivity and reduced regional gamma power have been associated with attentional deficits. Therefore, gamma tACS may modulate both regional activity and long-range functional connectivity, offering a promising neuromodulation strategy to alleviate ADHD symptoms.
In this context, the present study aims to investigate the effects of bilateral gamma-frequency tACS applied to the prefrontal cortex on attention and executive function performance in individuals with ADHD. Changes in gamma oscillatory activity will be measured using EEG to assess the neurophysiological impacts of stimulation. The study seeks to evaluate whether gamma tACS can serve as a targeted, evidence-based intervention to address the neurofunctional deficits observed in ADHD, potentially offering a novel therapeutic approach.
- Being tested
- Application tACS- 80 Hz, Application tACS -40 Hz, Application TACS - (6-80 Hz), Application TACS- Individual Gamma Hz, Application TACS- Sham
- Keywords
- gamma, EEG, tACS
- Medical subject headings
- Attention Deficit Disorder with Hyperactivity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Application tACS- 80 HzDevice
In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at various gamma frequencies (80 Hz).The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4).
Application tACS -40 HzDevice
In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at gamma frequencies (40 Hz). The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4).
Application TACS - (6-80 Hz)Device
In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at theta- gamma coupling frequencies ( 6-80 Hz). The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4).
Application TACS- Individual Gamma HzDevice
In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at individual gamma frequencies . The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4).
Application TACS- ShamDevice
In this study, a single 20-min tACS session will be applied over the bilateral dorsolateral prefrontal cortex (DLPFC) in a sham application. The anodal surface electrode will be placed over the left DLPFC (F3 of the 10-20 system) and the cathodal electrode will be placed over the right DLPFC (F4).
| Study group | Role | What they receive |
|---|---|---|
| 80 Hz Group | Experimental | Transcranial alternating current stimulation (tACS) at 80 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. Receives: Device: Application tACS- 80 Hz |
| 6-80 Hz Group | Experimental | Transcranial alternating current stimulation (tACS) at 6-80 Hz theta- gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. Receives: Device: Application TACS - (6-80 Hz) |
| Sham Group | Sham comparator | Transcranial alternating current stimulation (tACS) sham will be applied to the the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. Receives: Device: Application TACS- Sham |
| 40 Hz Group | Experimental | Transcranial alternating current stimulation (tACS) at 40 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. Receives: Device: Application tACS -40 Hz |
| Individual Gamma Group | Experimental | Transcranial alternating current stimulation (tACS) at ındividual gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. Receives: Device: Application TACS- Individual Gamma Hz |
What is being measured
The primary outcome is the main question the study is designed to answer.
Öktem Verbal Memory Test
Öktem Verbal Memory Test is a test of verbal memory processes, developed and validated by Öktem in 1992. It is designed to measure various variables related to memory.
Measured: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Forward and Backward Digit Span
This test, which is a subtest of the Wechsler Memory Scale, was developed to assess overall attention. It consists of two stages. The first stage evaluates the forward digit span, composed of random sequences ranging from 2 to 8 digits. In the second stage, the backward digit span is assessed using random sequences of 2 to 7 digits. In the first stage, numbers are read aloud with one-second intervals, and participants are expected to repeat the sequences exactly as presented. In the second stage, numbers are again read with one-second intervals, but participants are required to repeat the digits in reverse order. The test is terminated if the participant makes consecutive errors. The forward digit span assesses sustained attention, while the backward span also evaluates working memory performance.
Measured: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Verbal fluency tests
Verbal fluency tests measure the ability to generate words within a specific category over a limited time period. Verbal fluency performance has been associated not only with general language skills and semantic memory functions but also with executive functions such as attention, working memory, and processing speed. In this study, semantic and phonemic fluency tasks will be used.
Measured: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Resting State EEG and TASK EEG
The EEG recordings of the participants will be conducted using a BrainAmp 64-channel DC system. A 64-channel EasyCap will be used. AFz will serve as the ground electrode, and FCz will be used as the reference electrode. Impedance values will be maintained below 10 kOhm. EEG data will be recorded using the BrainVision Recorder software (Brain Products, Munich, Germany) with a band-pass filter set between 0.01 and 250 Hz.A 4-minute eyes-open and a 4-minute eyes-closed resting-state EEG recording will be conducted. EEG will also be recorded during the 2-back task and the memory task. 2-back Task: A visual n-back task will be administered to assess working memory. The task load will consist of 8-minute sessions. Memory Task: The memory task, which involves both encoding and retrieval of episodic information, will be examined using a visual memory paradigm presented to the participants.
Measured: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Aug 2025
- Study start1 Oct 2025 (estimated)
- Primary completion30 Dec 2025 (estimated)
- Study completion30 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Attention Deficit Disorder With Hyperactivity (ADHD)Studies of the same condition, open and under way.
- 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
- Factorial
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medipol University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, FATMA AYDIN, Medipol University
- Investigators
- Lütfü Hanoğlu, Study director, Medipol UniversitySuat Yılmaz, Principal investigator, Medipol UniversityGülsüm Uzer, Principal investigator, Medipol University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07145593
- Sponsor's protocol ID
- E-10840098-202.3.02-4603
- Status last verified
- Aug 2025
- First submitted
- 30 Jul 2025
- Last updated
- 28 Aug 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 28 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Gamma Transcranial Alternating Current Stimulation in Attention Deficit Hyperactivity Disorder
- ClinicalTrials.gov ID
- NCT07145593
- Acronym / sponsor ID
- E-10840098-202.3.02-4603
- Keywords
- gamma, EEG, tACS
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Medipol UniversityUniversity, hospital or other
- Study start
- 1 Oct 2025 (estimated)
- Primary completion
- 30 Dec 2025 (estimated)
- Study completion
- 30 Dec 2027 (estimated)
- First posted
- 28 Aug 2025 (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.
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by symptoms of inattention, impulsivity, and hyperactivity. These symptoms are often associated with impairments in executive functions and working memory, which are essential for goal-directed behavior and cognitive control. Deficits in these domains can significantly hinder individuals' academic, social, and daily functioning. Gamma oscillations (30-80 Hz) play a crucial role in cognitive integration, attention, and memory processes, and are thought to emerge from the balance between excitatory and inhibitory neuronal activity.
Transcranial Alternating Current Stimulation (tACS) is a non-invasive brain stimulation technique that modulates neuronal activity through rhythmic electrical currents. Recent studies suggest that gamma-frequency tACS applied to the prefrontal cortex can enhance cognitive performance and attentional processes. In individuals with ADHD, disrupted gamma connectivity and reduced regional gamma power have been associated with attentional deficits. Therefore, gamma tACS may modulate both regional activity and long-range functional connectivity, offering a promising neuromodulation strategy to alleviate ADHD symptoms.
In this context, the present study aims to investigate the effects of bilateral gamma-frequency tACS applied to the prefrontal cortex on attention and executive function performance in individuals with ADHD. Changes in gamma oscillatory activity will be measured using EEG to assess the neurophysiological impacts of stimulation. The study seeks to evaluate whether gamma tACS can serve as a targeted, evidence-based intervention to address the neurofunctional deficits observed in ADHD, potentially offering a novel therapeutic approach.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind (participant)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| 80 Hz Group | Experimental | Device: Application tACS- 80 HzTranscranial alternating current stimulation (tACS) at 80 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. |
| 6-80 Hz Group | Experimental | Device: Application TACS - (6-80 Hz)Transcranial alternating current stimulation (tACS) at 6-80 Hz theta- gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. |
| Sham Group | Sham comparator | Device: Application TACS- ShamTranscranial alternating current stimulation (tACS) sham will be applied to the the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. |
| 40 Hz Group | Experimental | Device: Application tACS -40 HzTranscranial alternating current stimulation (tACS) at 40 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. |
| Individual Gamma Group | Experimental | Device: Application TACS- Individual Gamma HzTranscranial alternating current stimulation (tACS) at ındividual gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Being between 18 and 40 years of age
- Receiving an ADHD diagnosis
- Scoring above 25 on the Montreal Cognitive Assessment (MoCA)
- Being right-handed
Key exclusion criteria (2 listed)
- Use of medications with sedative or stimulant effects
- Presence of metal brain implants or a pacemaker
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 |
|---|---|---|
| Application tACS- 80 HzIn this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at various gamma frequencies (80 Hz).The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4). | Device | 80 Hz Group |
| Application tACS -40 HzIn this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at gamma frequencies (40 Hz). The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4). | Device | 40 Hz Group |
| Application TACS - (6-80 Hz)In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at theta- gamma coupling frequencies ( 6-80 Hz). The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4). | Device | 6-80 Hz Group |
| Application TACS- Individual Gamma HzIn this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at individual gamma frequencies . The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4). | Device | Individual Gamma Group |
| Application TACS- ShamIn this study, a single 20-min tACS session will be applied over the bilateral dorsolateral prefrontal cortex (DLPFC) in a sham application. The anodal surface electrode will be placed over the left DLPFC (F3 of the 10-20 system) and the cathodal electrode will be placed over the right DLPFC (F4). | Device | Sham Group |
Primary outcome
Öktem Verbal Memory Test
Time frame: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Öktem Verbal Memory Test is a test of verbal memory processes, developed and validated by Öktem in 1992. It is designed to measure various variables related to memory.
Forward and Backward Digit Span
Time frame: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
This test, which is a subtest of the Wechsler Memory Scale, was developed to assess overall attention. It consists of two stages. The first stage evaluates the forward digit span, composed of random sequences ranging from 2 to 8 digits. In the second stage, the backward digit span is assessed using random sequences of 2 to 7 digits. In the first stage, numbers are read aloud with one-second intervals, and participants are expected to repeat the sequences exactly as presented. In the second stage, numbers are again read with one-second intervals, but participants are required to repeat the digits in reverse order. The test is terminated if the participant makes consecutive errors. The forward digit span assesses sustained attention, while the backward span also evaluates working memory performance.
Verbal fluency tests
Time frame: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
Verbal fluency tests measure the ability to generate words within a specific category over a limited time period. Verbal fluency performance has been associated not only with general language skills and semantic memory functions but also with executive functions such as attention, working memory, and processing speed. In this study, semantic and phonemic fluency tasks will be used.
Resting State EEG and TASK EEG
Time frame: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)
The EEG recordings of the participants will be conducted using a BrainAmp 64-channel DC system. A 64-channel EasyCap will be used. AFz will serve as the ground electrode, and FCz will be used as the reference electrode. Impedance values will be maintained below 10 kOhm. EEG data will be recorded using the BrainVision Recorder software (Brain Products, Munich, Germany) with a band-pass filter set between 0.01 and 250 Hz.A 4-minute eyes-open and a 4-minute eyes-closed resting-state EEG recording will be conducted. EEG will also be recorded during the 2-back task and the memory task. 2-back Task: A visual n-back task will be administered to assess working memory. The task load will consist of 8-minute sessions. Memory Task: The memory task, which involves both encoding and retrieval of episodic information, will be examined using a visual memory paradigm presented to the participants.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Aug 2025.
- Individual participant dataSharing planned: Undecided
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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.
Lütfü Hanoğlu study director
Medipol University
Suat Yılmaz principal investigator
Medipol University
Gülsüm Uzer principal investigator
Medipol University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Application tACS- 80 Hz, Application tACS -40 Hz and Application TACS - (6-80 Hz) in people with Attention Deficit Disorder With Hyperactivity (ADHD), run by Medipol University at 1 site in Turkey (Türkiye).
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 4 inclusion and 2 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: enrolling by invitation, as of the sponsor's last update on 28 Aug 2025. 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 Turkey (Türkiye). 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?
This study is still under way. Results are not available in the source record yet.
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?
Öktem Verbal Memory Test (time frame: Pre-tACS Baseline (prior to stimulation) / Post-tACS (within 30 minutes after stimulation)). The study lists 4 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 28 Aug 2025.