Gamma tACS in Attention-Deficit/Hyperactivity Disorder

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 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.

Conditions

• Attention Deficit Disorder With Hyperactivity (ADHD)

Interventions

DEVICE

Application tACS- 80 Hz

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).

DEVICE

Application tACS -40 Hz

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).

DEVICE

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

Application TACS- Individual Gamma Hz

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).

DEVICE

Application TACS- Sham

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).

Sponsors & Collaborators

• Medipol University

  lead OTHER

Principal Investigators

• Lütfü Hanoğlu · Medipol University

• Suat Yılmaz · Medipol University

• Gülsüm Uzer · Medipol University

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

FACTORIAL

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-10-01

Primary Completion

2025-12-30

Completion

2027-12-30

Countries

• Turkey (Türkiye)

Study Locations