Self-referential processing in depressed adolescents: A high-density event-related potential study.

Abstract

Despite the alarming increase in the prevalence of depression during adolescence, particularly among female adolescents, the pathophysiology of depression in adolescents remains largely unknown. Event-related potentials (ERPs) provide an ideal approach to investigate cognitive-affective processes associated with depression in adolescents, especially in the context of negative self-referential processing biases. In this study, healthy (n = 30) and depressed (n = 22) female adolescents completed a self-referential encoding task while ERP data were recorded. To examine cognitive-affective processes associated with self-referential processing, P1, P2, and late positive potential (LPP) responses to negative and positive words were investigated, and intracortical sources of scalp effects were probed using Low Resolution Electromagnetic Tomography (LORETA). Additionally, we tested whether key cognitive processes (e.g., maladaptive self-view, self-criticism) previously implicated in depression related to ERP components. Relative to healthy female subjects, depressed females endorsed more negative and fewer positive words, and free recalled and recognized fewer positive words. With respect to ERPs, compared to healthy female adolescents, depressed adolescents exhibited greater P1 amplitudes following negative words, which was associated with a more maladaptive self-view and self-criticism. In both early and late LPP responses, depressed females showed greater activity following negative versus positive words, whereas healthy females demonstrated the opposite pattern. For both P1 and LPP, LORETA revealed reduced inferior frontal gyrus activity in response to negative words in depressed versus healthy female adolescents. Collectively, these findings suggest that the P1 and LPP reflect biased self-referential processing in female adolescents with depression. Potential treatment implications are discussed.

Sustained engagement of attention is associated with increased negative self-referent processing in major depressive disorder

“…A waveform that they believed to be an element of the late positive complex or P300, at a similar time frame to the LPP, was attenuated in response to all stimuli in parietal regions. Notably, these findings are in the opposite direction to the results reported above (e.g., the LPP measured at a similar point in time was increased in depressed female adolescents in Auerbach et al, 2015). …”

“…Although the 1800ms period between the stimulus offset and behavioral response allows for the recording of neural response to stimuli, this extended period renders the reaction time response less meaningful and difficult to interpret 2 . Thus, we focus on ERP responses to word stimuli rather than reaction time in our analyses, which is consistent with prior work in this area (e.g., Auerbach et al, 2015). Participants completed several neutral practice trials before the task began to ensure that they knew to wait to respond until the question appeared.…”

“…A priori power analyses were conducted to determine sample size necessary to achieve a medium-to-large effect size (η 2 = 0.22), as per Auerbach, Stanton, Proudfit, and Pizzagalli (2015) for multivariate ANOVA; with the current sample size, we would achieve 80% power.…”

“…Participants view the words on a computer screen and make rapid judgments following the word’s display. In this version, participants viewed 40 negative and 40 positive words (as in Auerbach et al, 2015 1 ) selected from the Affective Norms for English Words (Bradley & Lang, 2010) for a total of 80 trials.…”

“…This suggests that MDD participants selectively attended to negative information (due to the initial P2 amplitude difference from controls) and were engaging in increased cognitive evaluation of negative information (due to the increases in the LPP compared to healthy controls). Similarly, in a sample of depressed and healthy female adolescents, depressed girls were shown to exhibit greater early (P1) amplitudes in response to negative words, and greater later (LPP) amplitudes to negative words (Auerbach, Stanton, Proudfit, & Pizzagalli, 2015). These findings are consistent with the results of prior work, with the MDD group showing early attention to negative words that continues over the time-course of the ERP.…”