Stress and reward: A multimodal assessment of childhood sexual abuse

Abstract

Background: Childhood adversity has been found to impact stress and brain reward systems but it is unclear whether interactions between these systems might explain resilient vs. non-resilient trajectories following childhood sexual abuse (CSA). To address this gap, we adopted a multimodal approach in which cortisol reactivity to an acute stressor was assessed in conjunction with behavioral and neural measures of reward responsiveness in females with major depressive disorder (MDD) or no psychiatric disorders (i.e., resilient) who experienced CSA compared to females with and without MDD who did not experience abuse.

Methods: Latent Class Mixed Modelling (LCMM) identified classes of adults (n = 62; M_Age = 26.48, SD = 5.68) characterized by distinct cortisol trajectories in response to a combined social evaluative cold pressor task. Classes were examined for their history of CSA and resilience as well as behavioral and neural measures of reward responsiveness using 128-channel electroencephalography (event-related potentials and source localization analysis).

Results: LCMM analysis identified two distinct classes of individuals with increased (Responders) or blunted (Non-Responders) cortisol reactivity to an acute stressor. Unlike Responders, Non-Responders did not modulate reward responses throughout the stress manipulation. No differences emerged between Responders and Non-Responders in terms of CSA or resilience. However, exploratory results showed that blunted cortisol response and non-modulation of reward responses emerged for those who experienced CSA at a younger age.

Conclusions: Co-occurring blunted stress and reward reactivity emerged irrespective of adults' experience of CSA or resilience. However, preliminary findings showed that CSA ending during peripubertal development was associated with blunted cortisol and reward responsiveness. Future research needs to replicate findings in larger samples and could investigate if increasing reward responsiveness during critical times of neurodevelopment could normalize stress reactivity to future stressors and thus promote resilience.

Keywords: Childhood sexual abuse; Cortisol; Major depression disorder; Resilience; Reward; Stress.

Fig. 1

Schematic diagram illustrating the timeline and design of the session. Participants provided written consent before completing the baseline saliva sample and baseline affect measures followed by the pre-stress Probabilistic Reward Task (PRT 1) and additional pre-stress affect measures. Then, the MAST (stress manipulation) was administered followed by stress onset saliva sampling, affect measures and the acute stress probabilistic reward task (PRT2 Block 1). Another acute stress saliva sample and affect measures were collected before transitioning to PRT2 Block 2 and the final acute saliva sample after completion of PRT Block 2. To prolong the acute stress effect, participants were initially told that their performance was ‘not good enough’ and that the MAST had to be repeated after the remaining tasks. Relief (i.e., being told not needing to repeat procedure) occurred after the last PRT block and the acute saliva sample. This was followed by PostRelief affect measures and finally a PostRelief saliva sample. 128-channel EEG data were collected during the PRT tasks, from which ERPs (Reward Positivity) and source-localization (standardized Low Resolution Electromagentic Tomography; sLORETA) data were computed.

Fig. 2

Trajectories of cortisol responses and self-reported affect during stress manipulation. (A) Applying LCMM to cortisol data revealed that the model with the best fit included two latent classes, labeled based on their distinct trajectories of cortisol response to stress as Non-Responders (n = 44) and Responders (n = 18). Note that Non-Responders did not vary in their cortisol responses to the stressor over time and entered the study with significantly higher levels of cortisol compared to Responders. **p < .01. (B–D) Self-reported affect during the session with Visual Analog Manual Scale (VAMS) ratings by class. Lower VAMS scores reflect greater negative affect.

Fig. 3

Changes in positive and negative affect and reward responsiveness during stress manipulation. Changes in (A–B) positive and negative affect measured using the Positive and Negative Affect Schedule (PANAS) and (C) state anxiety measured using Spielberger State Anxiety Inventory (STAI-S) across Responders and Non-Responders classes. (D) Response bias by class in the Probabilistic Reward Task (n = 62) before and during stress manipulation (Non-Responders = 44; Responders = 18). Significant differences in response bias emerged between Non-Responders and Responders at pre-stress but not at post-stress. Critically, only Responders increased their response bias from pre- to post-stress, with no significant change for Non-Responders. Error bars represent standard errors. *p < .05, ^*p = .05.