Increased neural sensitivity to self‐relevant stimuli in major depressive disorder

Abstract

The current research examined how individuals with depression process emotional, self‐relevant stimuli. Across two studies, individuals with depression and healthy controls read stimuli that varied in self‐relevance while EEG data were recorded. We examined the late positive potential (LPP), an ERP component that captures the dynamic allocation of attention to motivationally salient stimuli. In Study 1, participants read single words in a passive‐viewing task. Participants viewed negative, positive, or neutral words that were either normative or self‐generated. Exploratory analyses indicated that participants with depression exhibited affective modulation of the LPP for self‐generated stimuli only (both positive and negative) and not for normative stimuli; healthy controls exhibited similar affective modulation of the LPP for both self‐relevant and normative stimuli. In Study 2, using a separate sample and a different task, stimuli were provided within the context of sentence stems referring to the self or other people. Participants with depression were more likely to endorse negative self‐referent sentences and reject positive ones compared to healthy controls. Depressed participants also exhibited an increased LPP to negative stimuli compared to positive or neutral stimuli. Together, these two studies suggest that depression is characterized by relatively increased sensitivity to affective self‐relevant stimuli, perhaps in the context of a broader reduction in emotional reactivity to stimuli that are not self‐relevant. Thus, depression may be characterized by a more nuanced pattern based on the degree of stimulus self‐relevance than either a global decrease or increase in reactivity to affective stimuli.

No Self Without Salience: Affective and Self-relevance Ratings of 552 Emotionally Valenced and Neutral Dutch Words

“…The present findings also provide support for existing research (Benau et al, 2019;Bromgard et al, 2006) indicating that self-relevance influences greater levels of felt intensity, that is, within its representative valence. The current outcomes indicate that positively valenced self-relevant words have higher intensity compared to positive non-self-relevant words.…”

Emotion context insensitivity in depression: Toward an integrated and contextualized approach

“…It is plausible that depressed individuals preoccupied with personal stressors, may be less reactive to standardized negative emotional stimuli. Indeed, there is some evidence that depressed individuals show greater neurophysiological reactivity to personally relevant positive and negative stimuli, as indexed by the LPP (Benau et al., 2019). The differences in timescale between laboratory and daily life measures may also play a role, as laboratory measures typically assess changes on the level of seconds or minutes, while daily life measures assess over the course of minutes, hours, or days.…”

Depressive rumination is correlated with brain responses during self-related processing

“…This is in contrast to controls, where positive words induce greater evoked responses (Auerbach et al, 2016, 2015; Shestyuk and Deldin, 2010). In patients, the magnitude of the difference between LPPs induced by positive and negative words appears to increase with symptom severity (Benau et al, 2019), suggesting that people with depression may selectively elaborate upon negative emotional self-related information. Notably, and in contrast to these prior studies, the task used here does not involve an emotional component.…”