Electrocortical reactivity during self-referential processing in current and remitted depression

Negative cognitions and self-views are proposed to contribute to the onset and maintenance of depression. Biased self-referential processing has been documented in depression using behavioral (recall bias) and neural (late positive potential [LPP] event-related potential) measures in response to positive and negative words. However, it remains unclear whether such biases reflect a vulnerability (i.e., are evident even outside of a depressive episode) or are mood-dependent (i.e., evident only during a depressive episode). In this study, 33 adults with current depression (M_age = 41.87 years; 84.4% female), 19 adults with remitted depression (M_age = 39.61 years; 78.9% female), and 30 never-depressed controls (M_age = 39.15 years; 80% female) completed a self-referential encoding task (SRET) including positive and negative words. Behavioral recall biases and LPP (referenced to averaged mastoids) responses during early (automatic processing) and late (sustained, elaborative engagement) windows were assessed. Behaviorally, adults with current and remitted depression exhibited greater negative and reduced positive recall bias compared to controls. Neurally, adults with current depression showed a blunted early LPP to positive words and reduced late LPPs overall, suggesting deficits in both automatic and sustained, elaborative self-referential processing. The remitted depression group demonstrated intermediate responses, falling between current and never-depressed controls. Findings indicate that behavioral measures may capture trait-like negative self-referential bias independent of depressed mood, while neural measures revealed stage-specific deficits providing unique insight into depression. Future research should employ longitudinal designs to determine whether behavioral and neural measures reflect vulnerability or mood-dependent processes.