# Executive function and neural oscillations in adults with attention-deficit/hyperactivity disorder: a systematic review

## TL;DR

This study reviews how brain activity patterns differ in adults with ADHD compared to healthy individuals, focusing on brain waves linked to attention and decision-making.

## Contribution

The study systematically reviews resting-state EEG and ERP differences in adult ADHD, linking them to executive function impairments.

## Key findings

- Adult ADHD patients show increased theta power in resting-state EEG.
- Reduced ERP amplitudes (Pe, P3, N2) are observed during response inhibition and sustained attention tasks.
- EEG changes suggest impairments in error detection, cognitive control, and attention allocation in ADHD.

## Abstract

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neurobiological disorder that often persists into adulthood. Adult ADHD is an important public health concern due to its great social damage and challenges in clinical recognition, resulting in a significant disease burden. Nonetheless, the diagnosis of adult ADHD remains challenging due to the absence of specific symptoms and biological markers. The aims of this systematic review were as follows: (1) To discern whether there were any differences in resting-state electroencephalogram (EEG) and event related potential (ERP) between adult ADHD and healthy controls (HCs). (2) To ascertain whether ERP specific manifestations associated with executive function (EF) deficiencies. (3) To conduct an exploration into the mechanisms of specific electrophysiologic alterations. This review was conducted in PubMed-Medline and Web-of-Science from 1971 to August 15th, 2024 to summarize the EEG changes of adult ADHD. We focused on resting-state EEG to report spectral power across different frequency bands and ERPs under different experimental tasks, 68 studies were finally included. When studying the characteristics of resting-state EEG in adult ADHD patients, we observed that theta power exhibits a consistent upward trend. Congruous reduction Pe, P3, and N2 amplitudes during response inhibition tasks, with a further decrease in P3 and N2 amplitudes in sustained attention tasks. These EEG changes may stem from impairments in error detection, cognitive control, and attention allocation, meaning that core EFs are affected in adults with ADHD. Overall, consistent changes in resting-state EEG and ERPs could provide insight for the identification of ADHD in adults.