Frequency-specific QEEG spectral power correlates of positive and negative symptom severity in recent-onset schizophrenia.

The study found that different symptom dimensions were associated with different regional EEG-frequency patterns. The result is preliminary and does not establish a diagnostic test or a treatment-selection tool.

Vahid-Vahdat P, Naghdi Sadeh R, Samadzadehaghdam N, Ebrahimi-Kalan A, Farhang S.
Neuroscience · Publication date: 2026-09-18
Added to site: 2026-09-19
DOI: 10.1016/j.neuroscience.2026.09.018

Online-ahead-of-print publication date verified in PubMed.

Modalities

QEEG, EEG

Clinical focus

Schizophrenia spectrum disorders, Spectral power, Symptom dimensions

Population

Azeri adults in Tabriz, Iran, with schizophrenia spectrum disorders of less than five years' duration

Sample

18 participants

Intervention / method

Eyes-open resting 19-channel EEG, multitaper spectral-power estimation across ten bands from delta through gamma 2, and FDR-corrected Spearman correlations with Positive and Negative Syndrome Scale items

Comparator

No healthy or clinical control group; symptom dimensions were compared within the patient sample

Clinician summary

Higher frontal, central and temporal delta power correlated with more severe positive symptoms. Higher central-parietal theta and gamma power correlated with selected negative and general symptoms, while lower theta, alpha and beta power tracked suspiciousness or grandiosity.

How to interpret the findings

The sample was small, cross-sectional, single-site and culturally specific, with no control group or diagnostic-accuracy testing. Correlations cannot establish causation, clinical utility, treatment response or generalizability, even with false-discovery-rate correction.

Equipment and disclosures

Eyes-open resting EEG was recorded from 19 standard 10-20 sites; the manufacturer and acquisition system were not specified in the accessible abstract.

The authors declared no known competing financial interests or personal relationships. Funding was not reported in the checked indexed record.

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