The electroencephalography protocol for the Accelerating Medicines Partnership® Schizophrenia Program: Reliability...

Area of Science:

• Neuroscience
• Psychiatry
• Biomarkers

Background:

• Individuals at clinical high risk for psychosis (CHR) exhibit variable outcomes, necessitating personalized treatments.
• Current antipsychotic medications carry risks, highlighting the need for safer alternatives in CHR individuals.
• The Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ) Program aims to develop novel treatments for psychosis.

Purpose of the Study:

• To assess the test-retest reliability and stability of electroencephalography (EEG)-based measures in CHR participants.
• To evaluate EEG measures as potential biomarkers for clinical outcomes and illness progression in CHR.
• To determine the suitability of EEG measures for use in clinical trials for CHR individuals.

Main Methods:

• The study analyzed EEG data, including event-related potentials (ERPs) and resting EEG power spectral density (PSD), from CHR and control participants.
• Measures assessed included mismatch negativity (MMN), P300 (P3a and P3b), and 40-Hz auditory steady-state response.
• Reliability was quantified using Generalizability (G)-coefficients, and changes over time were analyzed with paired t-tests.

Main Results:

• EEG measures demonstrated good to excellent test-retest reliability in both CHR and control groups (G-coefficients generally > 0.70).
• Significant habituation effects (decreases in measure magnitudes) were observed over sessions and within sessions for several EEG measures.
• Despite habituation, the overall reliability of the EEG measures was robust.

Conclusions:

• EEG-based measures, including ERPs and PSD, exhibit sufficient test-retest reliability for use in CHR studies.
• These reliable EEG markers can serve as predictors of clinical outcomes and indicators of illness progression in CHR.
• The findings support the use of AMP SCZ EEG measures as outcome measures in controlled clinical trials for CHR individuals.