Human resilience to stress: role of brain functions

Author: Nils Kohn
Affiliation(s): Radboud university medical centre
Research question(s): 

• How do emotion regulation and reward related brain circuits and their interaction connect childhood adversity with resilience in humans?
• Can childhood adversity impact resilience to recent life stress in adulthood? Can emotion and reward functions connect the pathway from childhood adversity to adulthood resilience when facing recent life stress?
• How do the results from performance and stress-based resilience scores differentially and jointly explain striatal and amygdala-hippocampus functional topography?

Link: AsPredicted Preregistration

Abstract:
Stress exposure is a main predictor of mental health problems. However, there is a large individual difference in how people react to stress. Stressful experiences in early development might impact brain functioning, such as the functional connectivity in emotion and reward circuits (Herzberg & Gunnar, 2020). Furthermore, resilient individuals showed consistent brain patterns in specific regions like the amygdala and ventral striatum (Eaton et al., 2022). Here, we propose that altered emotion and reward functions at the neural level may connect stress with resilience and act as protective roles underlying the resilient brain. 
Based on the definition of positive adaptation under stress (Tabibnia, 2020), we operationalize outcome-oriented resilience as the residual score from the regression of stress levels to predict mental health. We divide our proposal into two aims. Objective 1 explores how brain functions and/or their interactions link childhood adversity to subsequent mental health. We hypothesize that resilience in relation to childhood stress would be associated with the connection topography in the striatum (reward processing) and the amygdala-hippocampus complex (emotion regulation).
According to the stress sensitization model, individuals show increased stress sensitivity across time (Stroud et al., 2020). Therefore, distal adversities exposure in childhood may result in resilience or vulnerability to proximal stress even in adulthood. Objective 2 aims to investigate the pathway from adversity exposure in childhood to stress resilience in adulthood. We estimate that emotion regulation and reward related brain functions moderate this relationship. 
Identifying the roles of brain functions in the connection from stress to resilience may provide insights into the prevention and intervention of stress-related disorders. We aim to merge the results of the two objectives to determine a stress-based and function-based resilience score and explore the potential differential relation to reward or emotion regulation related brain circuits.