Different Spectral Analysis Methods for the Theta/Beta Ratio Calculate Different Ratios But Do Not Distinguish ADHD...

Area of Science:

• Neuroscience
• Child and Adolescent Psychiatry
• Biomedical Engineering

Background:

• The Theta/Beta Ratio (TBR) has been investigated as an electroencephalogram (EEG)-based biomarker for Attention Deficit Hyperactivity Disorder (ADHD).
• Previous research indicated significant TBR differences between ADHD patients and controls.
• Recent meta-analyses show a declining effect size for TBR in ADHD diagnosis over the past decade.

Purpose of the Study:

• To investigate if variations in EEG signal processing algorithms contribute to the heterogeneity of findings regarding the Theta/Beta Ratio (TBR) in ADHD diagnosis.
• To assess the clinical usability of TBR calculated via different processing methods for distinguishing ADHD from controls.

Main Methods:

• EEG data from two multi-center clinical studies were analyzed.
• Five distinct EEG signal processing algorithms were employed to compute the TBR.
• The clinical utility of the resulting TBRs was evaluated using the iSPOT-A dataset.

Main Results:

• Different EEG processing methods yielded significantly different TBR values.
• Despite these differences, none of the tested TBR calculation methods could significantly distinguish between children with and without ADHD.
• No consistent associations were found between the calculated TBRs and ADHD symptom severity.

Conclusions:

• Variations in EEG signal processing significantly impact TBR calculations but do not improve diagnostic accuracy for ADHD in this sample.
• The observed secular decline in effect size for TBR is likely attributable to factors beyond EEG processing, such as sleep duration and control group inclusion criteria.