Fronto-Parietal Transcranial Alternating Current Stimulation for ADHD in Children and Adolescents

Effects and Neural Mechanisms of Fronto-Parietal Transcranial Alternating Current Stimulation in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition in children and adolescents and is often associated with difficulties in attention, inhibitory control, working memory, and other executive functions. The fronto-parietal brain network is thought to play an important role in these cognitive functions. Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that may influence brain activity. This study aims to evaluate whether 5-Hz tACS targeting the right frontal and parietal regions can improve executive functioning in children and adolescents aged 6 to 18 years with ADHD. The study also aims to explore whether any effects of tACS are related to changes in brain activity measured by electroencephalography (EEG). Participants will receive both active tACS and sham stimulation in a randomized, double-blind, crossover design. Clinical symptoms, executive function performance, and EEG measures will be assessed before and after each stimulation session. The main hypothesis is that active fronto-parietal tACS will produce greater improvement in executive functioning than sham stimulation, and that these effects may be associated with changes in EEG-measured brain activity.

Inclusion Criteria:

1. Aged 6-18 years, Han Chinese, and right-handed;
2. Normal or corrected-to-normal vision and normal hearing;
3. Meets the DSM-5 diagnostic criteria for attention-deficit/hyperactivity disorder, predominantly inattentive presentation;
4. Meets the diagnostic threshold for inattention based on the parent-rated SNAP-IV scale;
5. Performance on the symbol cancellation test, converted to a grade-standardized score, is below the average level;
6. Has normal intelligence as confirmed by a brief intelligence assessment, with no significant emotional disorder or severe physical illness;
7. Able to cooperate with electroencephalography recording and transcranial alternating current stimulation.

Exclusion Criteria:

1. Meets diagnostic criteria for other major psychiatric disorders, such as schizophrenia or bipolar disorder;
2. Has severe physical diseases, such as significant intracranial lesions, thyroid disease, epilepsy, congenital heart disease, severe hematological disease, systemic lupus erythematosus, or significant visual or hearing impairment;
3. Has known obvious brain structural abnormalities based on available cranial imaging or medical history;
4. Has severe neurological disease, a clear family history of hereditary neurological disorders, or other conditions associated with high neurological risk;
5. Has metal implants or a cardiac pacemaker in the body, or has skull defects, holes, or fractures;
6. Is currently receiving other pharmacological or behavioral treatment for ADHD, such as methylphenidate medication or behavioral intervention.