Frontal alpha asymmetry is associated with chronic stress and depression, but not with somatoform disorders

• Published in: International journal of psychophysiology 2024-06, Vol.200, p.112342-112342, Article 112342
• Main Authors: Périard, Isabelle Anne-Claire, Dierolf, Angelika Margarete, Lutz, Annika, Vögele, Claus, Voderholzer, Ulrich, Koch, Stefan, Bach, Michael, Asenstorfer, Carina, Michaux, Gilles, Mertens, Vera-Christina, Schulz, André
• Format: Article
• Language: English
• Subjects: Adult; Alpha Rhythm - physiology; Chronic Disease; Chronic stress; Depression; Depression - physiopathology; Electroencephalography; Female; Frontal alpha asymmetry; Frontal Lobe - physiopathology; Functional Laterality - physiology; Humans; Illness anxiety; Male; Middle Aged; Somatoform disorders; Somatoform Disorders - physiopathology; Stress, Psychological - physiopathology; Young Adult
• ISSN: 0167-8760; 1872-7697
• DOI: 10.1016/j.ijpsycho.2024.112342

Cardinal characteristics of somatoform disorders (SFDs) are worry of illness, and impaired affective processing. We used relative frontal alpha asymmetry (FAA), a method to measure functional lateralization of affective processing, to investigate psychobiological correlates of SFDs. With alpha activity being inversely related to cortical network activity, relative FAA refers to alpha activity on the right frontal lobe minus alpha activity on the left frontal lobe. Less relative left frontal activity, reflected by negative FAA scores, is associated with lower positive and greater negative affectivity, such as observed in depression. Due to its negative affective component (illness anxiety), we expected to find less relative left frontal activity pattern in SFDs, and positive associations with self-reported chronic stress and depression symptoms. We recorded resting-state EEG activity with 64 electrodes, placed in a 10–10 system in 26 patients with a primary SFD, 23 patients with a major depressive disorder and 25 healthy control participants. The groups did not differ in FAA. Nevertheless, across all participants, less relative left frontal activity was associated with chronic stress and depression symptoms. We concluded that FAA may not serve as an indicator of SFDs. As the relationship of FAA and depressive symptoms was fully mediated by chronic stress, future studies have to clarify whether the association between FAA and chronic stress may represent a shared underlying factor for the manifestation of mental health complaints, such as depression. •Frontal alpha asymmetry (FAA) did not differ between patients with somatoform disorders (SFDs), depression, and healthy controls.•FAA was positively correlated with depression scores across all individuals.•The association of FAA and depression was fully mediated by chronic stress levels.