Interpersonal Trauma Effects on Adolescent Depression: The Moderating Role of Neurophysiological Responses to Positive Interpersonal Images

Trauma exposure is associated with a heightened risk for depression and such risk is thought to vary based on the type of traumatic events (e.g., interpersonal, including abuse and domestic violence, or non-interpersonal, including accidents or natural disasters). Depression is often accompanied by altered emotional reactivity, and the late positive potential (LPP) serves as a reliable neurophysiological measure of sustained attention towards emotional stimuli, raising questions regarding the role of the LPP in moderating trauma effects on depression. We conducted a cross-sectional study of 201 adolescents aged 14-17 years (61.2% female) who were oversampled for current depression and elevated risk of depression based on maternal history. Clinical interviews were conducted to assess diagnoses and lifetime trauma exposure, and participants reported on current depressive symptoms. Electroencephalogram (EEG) was continuously recorded while participants completed a previously validated interpersonal emotional images task. Cumulative trauma (CT) and interpersonal trauma (IPT) were both associated with greater depressive symptoms, but non-interpersonal trauma (NIPT) was not significantly related to depressive symptoms. The association between IPT and depressive symptoms was moderated by the LPP to positive interpersonal images, such that IPT-exposed adolescents with blunted neural responses to such images showed the greatest symptoms. This result was specific to IPT, and the LPP to threatening interpersonal images did not significantly moderate the effects of IPT on depressive symptoms. These findings highlight the unique effects of interpersonal trauma on depressive symptoms and elucidate a potential vulnerability linking trauma exposure to depression risk among adolescents.