Prefrontal EEG Delta-Beta Coupling Marks Depressed State in Adult Siblings

Abstract

Major depressive disorder (MDD) is marked by disorganization in electrophysiological brain networks, yet it remains unclear whether such disorganization reflects the state-dependent pathological effects or a trait-like vulnerability. We analyzed resting-state electroencephalographic (EEG) delta-beta phase-amplitude coupling (PAC) in two sibling cohorts. Current-MDD families included individuals with current MDD and their currently unaffected siblings (n=36), and remitted-MDD families comprised individuals with remitted MDD and their lifetime unaffected siblings (n=110). Delta-Betahigh PAC was significantly elevated (pcorr[≤]0.05) over the left-medial frontal region in participants with current MDD relative to their unaffected siblings. In the remitted-MDD families, no significant differences were observed. Regrouping all individuals irrespective of family ties into current MDD, remitted MDD, and never-depressed controls confirmed significantly elevated frontal delta-Betahigh PAC at rest in the current-MDD subgroup compared to other subgroups. Overall, delta-Betahigh coupling reflects the depressive state rather than a trait-like or familial vulnerability.