Resting state EEG source derived salience network theta connectivity mediates anxiety in community dwelling individuals reporting childhood trauma.

Childhood trauma (CT) has been consistently linked with etiology of anxiety and depression. Finding biomarkers that mediate the relationship between CT and psychopathology is important and electroencephalography (EEG) can be a useful and cost-effective tool serving this purpose. Hence, in the current research we investigated resting state EEG biomarkers associated with CT and how these may link to psychopathology of anxiety and depression in adults. A total of 324 community recruited participants (age range 15-93 years) completed standard self-report scales of CT, anxiety and depression, and also underwent an eyes-closed resting state EEG recording session. Based on several functional neuroimaging studies, which have shown that connectivity in the salience network with major nodes in the anterior cingulate cortex (ACC) and insula is modulated by CT, we derived salience network connectivity measures from resting state EEG source imaging. Also given that theta band (3-7 Hz) neural oscillations have been shown to have an ACC source, we specifically focused on theta band salience network connectivity. The results showed significant positive correlation between CT and both anxiety and depression. We also found that theta band salience network connectivity, but not network activity, had a significant inverse relationship with CT and specifically mediated the relationship between CT and anxiety, but not depression. Interrogating the subcomponents of CT, theta connectivity in the salience network mediated the relationship between anxiety and both emotional abuse and physical neglect. These results showcase the utility of a resting state EEG source imaging-based biomarker in understanding the mechanistic associations between CT and psychopathology in community dwelling individuals.