Early Adversity and Mental Health Outcomes: Linking Extremely Low Birth Weight, Neuroendocrine Dysregulation, and Internalizing Behaviours

Abstract

<p>Salivary cortisol and electrocardiogram data was collected at baseline and after a stress-anticipation task in extremely low birth weight (ELBW; < 1000 grams) survivors and normal birth weight (NBW) controls, in order to examine the moderating influence of emotion regulation on the relationship between being born at ELBW and internalizing problems in adulthood. The stress manipulation was an adapted Trier Social Stress Task. The participants were told they would have three minutes to create a speech on one of three predetermined topics (i.e., gun control, same sex marriage, or abortion). After three minutes passed, the particpants were told that there would be no speech. All participants showed a decrease in salivary cortisol levels throughout the day, and an increase in heart rate during the stress anticipation task. When a median split was used to create high and low stress reactive cortisol and heart rate groups, an interaction was found between birth status (ELBW vs. NBW) and group (High vs. Low Stress Reactive Cortisol) on self-reported internalizing problems (anxiety, depression, withdrawal). Those born at ELBW who had high stress reactive cortisol self-reported significantly higher levels of internalizing problems compared to ELBWs with low stress reactive cortisol. Those born at NBW did not differ on self-reported internalizing problems based on their stress reactive cortisol levels. When the moderating effect was probed with a linear regression analysis, the ELBW group was driving the relation between stress reactive cortisol levels and internalizing problems. Taken together, the results suggest that emotion regulation, as indexed by the neuroendocrine system, is moderating the relation between being born at ELBW and internalizing problems in adulthood. This is indicative of a differential susceptibility of risk and resilency in ELBW survivors depending on their ability to regulate their emotions, specifically during periods of stress.</p>