Self-referential Processing in Remitted Depression: An Event-Related Potential Study

Identifying mechanisms of major depressive disorder (MDD) that continue into remission is critical, as this may contribute subsequent depressive episodes. Biobehavioral markers related to depressogenic self-referential processing biases have been identified in depressed adults. Thus, we investigated whether these risk factors persisted during remission as well as contributed to the occurrence of stress and depressive symptoms over time. At baseline, adults with remitted depression ( n =33) and healthy controls ( n =33) were administered diagnostic and stress interviews as well as self-report symptom measures. Additionally, participants completed the Self-Referential Encoding Task while EEG data were acquired. Stress interviews and self-report symptom measures were re-administered at the 6-month follow-up assessment. Drift diffusion modeling showed that compared to healthy individuals, adults with remitted depression exhibited a slower drift rate to negative stimuli, indicating a slower tendency to reject negative stimuli as self-relevant. At the 6-month follow-up assessment, a slower drift rate to negative stimuli predicted greater interpersonal stress severity among remitted depressed but not healthy individuals while controlling for both baseline depression symptoms and interpersonal stress severity. Highlighting the specificity of this effect, results were non-significant when predicting non-interpersonal stress. For self-relevant positive words endorsed, remitted depressed adults exhibited smaller left than right hemisphere late LPP amplitudes; healthy controls did not show hemispheric differences. Self-referential processing deficits persist into remission. In line with the stress generation framework, these biases predicted the occurrence of interpersonal stress, which may provide insight about a potential pathway for the re-emergence of depressive symptoms.