Resting-state frontal, frontlateral, and parietal alpha asymmetry:A pilot study examining relations with depressive disorder type and severity

Gabriela M Marcu; Raluca D Szekely-Copîndean; Ana-Maria Radu; Mihaela D Bucuță; Radu S Fleacă; Ciprian Tănăsescu; Mihai D Roman; Adrian Boicean; Ciprian I Băcilă

doi:10.3389/fpsyg.2023.1087081

Resting-state frontal, frontlateral, and parietal alpha asymmetry:A pilot study examining relations with depressive disorder type and severity

Front Psychol. 2023 Mar 7:14:1087081. doi: 10.3389/fpsyg.2023.1087081. eCollection 2023.

Authors

Gabriela M Marcu^{1

2

3}, Raluca D Szekely-Copîndean^{3

4}, Ana-Maria Radu^{1

3}, Mihaela D Bucuță^{1

5}, Radu S Fleacă⁶, Ciprian Tănăsescu⁶, Mihai D Roman⁶, Adrian Boicean⁶, Ciprian I Băcilă^{3

6}

Affiliations

¹ Department of Psychology, Lucian Blaga University of Sibiu, Sibiu, Romania.
² Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
³ Scientific Collective for Research in Neuroscience, Clinical Psychiatric Hospital "Dr. Gh. Preda", Sibiu, Romania.
⁴ Department of Social and Human Research, Romanian Academy, Cluj-Napoca, Romania.
⁵ Center for Psychological Research, Lucian Blaga University of Sibiu, Sibiu, Romania.
⁶ Faculty of Medicine, Lucian Blaga University of Sibiu, Sibiu, Romania.

Abstract

Introduction: The search for biomarkers has been central to efforts of improving clinical diagnosis and prognosis in psychopathology in the last decades. The main approach has been to validate biomarkers that could accurately discriminate between clinical diagnoses of very prevalent forms of psychopathology. One of the most popular electrophysiological markers proposed for discrimination in depressive disorders is the electroencephalography (EEG)-derived frontal alpha asymmetry. However, the validity, reliability and predictive value of this biomarker have been questioned in recent years, mainly due to conceptual and methodological heterogeneity.

Methods: In the current non-experimental, correlational study we investigated relationship of resting-state EEG alpha asymmetry from multiple sites (frontal, frontolateral, and parietal) with different forms of depressive disorders (varying in type or severity), in a clinical sample.

Results: Results showed that alpha asymmetry in the parietal (P3-P4) was significantly higher than in the frontal (F3-F4) and frontolateral sites (F7-F8). However, we did not find significant relations between alpha asymmetry indices and our depressive disorder measures, except for a moderate positive association between frontolateral alpha asymmetry (eyes-closed only) and depressive disorder severity (determined through clinical structured interview). We also found no significant differences in alpha asymmetry between participants, depending on their depression type.

Discussion: Based on results, we propose the parietal and frontolateral asymmetry indices to form hypotheses that should not be abandoned in the depression markers research, but worth for further experimental research. Methodological and clinical implications of the current findings are discussed.

Keywords: alpha asymmetry; biomarker; depression; depression severity; regional asymmetries; resting state EEG; treatment-resistant depression.