Past-year relational victimization is associated with a blunted neural response to rewards in emerging adults

Relations Between Neighborhood Disadvantage and Electrocortical Reward Processing in Youth at High and Low Risk for Depression

Neighborhood-level disadvantage during childhood is a determinant of health that is hypothesized to confer risk for psychopathology via alterations in neuro-affective processing, including reward responsiveness. However, little research has examined the impact of socioeconomic disadvantage assessed at the community-level on reward processing, which may have important implications for targeted dissemination efforts. Furthermore, not all youth exposed to neighborhood disadvantage may exhibit alterations in reward reactivity, highlighting the need to consider factors that may exacerbate risk for blunted reward reactivity. The current study examined associations between geocoded indices of neighborhood disadvantage and electrocortical reward responsivity in youth and tested whether findings were moderated by maternal history of depression. The sample included 137 youth recruited for studies on the intergenerational transmission of depression. Neighborhood disadvantage was assessed using the Area Deprivation Index (ADI) while the reward positivity (RewP), an event-related potential, indexed reward response. Results revealed a significant interaction between ADI and maternal history of depression on youth RewP, such that greater neighborhood disadvantage was significantly associated with lower reward responsiveness, but only for youth with a maternal history of depression. Results were maintained controlling for youth internalizing symptoms and individual-level socioeconomic factors. Findings suggest that neighborhood disadvantage may impact youth neural reward processing, at least partially independently of individual risk factors, for youth with a maternal history of depression. If replicated, results suggest intervention efforts may be implemented at the community level to enhance reward responsiveness, specifically for youth living in low-resourced neighborhoods with a maternal history of depression.

The effects of stress on reward responsiveness: a systematic review and preliminary meta-analysis of the event-related potential literature

Exposure to stressful events is associated with a range of negative physical and mental health outcomes, including depression. It is critical to understand the mechanisms through which stress impacts mental health to identify promising targets for prevention and intervention efforts. Low-reward responsiveness is thought to be a mechanism of effects of stress on negative health outcomes and can be reliably measured at the neurophysiological level by using event-related potentials (ERPs), such as the reward positivity (RewP) component. The goal of this systematic review and preliminary meta-analysis was to examine evidence of associations between stress and alterations in reward responsiveness measured using ERPs. Through a systematic review of the literature, 23 studies examining the effects of laboratory-induced stressors and naturalistic stressors or perceived stress on reward responsiveness met study criteria, 13 of which were included in the meta-analysis. Most studies were conducted in undergraduate and community samples, with three selected for specific conditions, and primarily in adults. The systematic review supported evidence of associations between laboratory-induced stressors and blunted reward responsiveness as measured by the RewP but there were more mixed results when considering direct associations between naturalistic stressors/perceived stress and reward-related ERPs. Given that all studies examined the RewP, the meta-analysis focused on this component and indicated that there was a weak, nonsignificant negative association between stress and RewP. Results emphasize the complex nature of relations between stress and reward-related ERPs and the need to consider alternative models in future research. We also provide reporting recommendations for ERP researchers to facilitate future meta-analyses.

Effects of the COVID-19 Pandemic on Neural Responses to Reward: A Quasi-experiment

BACKGROUND

The COVID-19 pandemic has been a prolonged period of stress due to social isolation, illness, death, and other major life disruptions. Neural reward sensitivity, essential for healthy functioning, may become reduced under major naturalistic stressors, though few studies have examined this. The present study sought to test whether neural responses to rewards were significantly blunted by the stress of the pandemic.

METHODS

We compared 2 groups of young adult participants, who completed a monetary reward task while an electroencephalogram was recorded, at 2 time points, 1 to 3 years apart. Our measure of reward sensitivity was the reward positivity (RewP), a neural marker enhanced to gain relative to loss feedback. The magnitude of the RewP is sensitive to stress exposure and can prospectively predict depression. The pre-pandemic group (n = 41) completed both time points before the pandemic, while the pandemic group (n = 39) completed the baseline visit before the pandemic and the follow-up visit during its second year.

RESULTS

The pandemic group reported having experienced significant stressors over the course of the pandemic. We did not observe a significant decrease in the RewP from baseline to follow-up in the pre-pandemic group. In contrast, in the pandemic group, the RewP was significantly blunted at the follow-up visit to the extent that it no longer distinguished gain from loss feedback.

CONCLUSIONS

These results suggest that prolonged naturalistic stressors can result in adaptations in neural responses to rewards. Our findings also highlight a possible mechanism linking stress to the development of depression.

Risk factors for the intergenerational transmission of depression in women and girls: Understanding neural correlates of major depressive disorder and the role of early-onset maternal depression

Deficits in neural reward processing have been implicated in the etiology of depression and have been observed in high-risk individuals. However, depression is a heterogeneous disorder, and not all depressed individuals exhibit blunted neural reward response, suggesting the need to examine more specific depression phenotypes. Early-onset depression, a well-defined phenotype, has been associated with greater intergenerational transmission of depression and appears more closely linked to neural reward processing deficits. The present study examined whether a maternal history of early-onset depression was associated with neural reward response among mothers and their daughters. Mothers with and without a history of depression, as well as their biological, adolescent daughters (N = 109 dyads), completed a monetary reward guessing task while electroencephalogram was collected. Analyses focused on the Reward Positivity (RewP), an event-related potential following reward receipt. Adjusting for current depressive symptoms, maternal early-onset depression was associated with a blunted RewP in the mothers and a numerically smaller RewP in their never-depressed, adolescent daughters. Maternal adult-onset depression was not statistically associated with a blunted RewP in mothers or daughters. Thus, a blunted RewP appears to be a trait-like vulnerability marker for depression that emerges before depression onset and relates to more specific depression phenotypes (e.g., early-onset depression). These findings have implications for early identification of individuals at risk of depression and for developing more targeted interventions.

Neural response to social but not monetary reward predicts increases in depressive symptoms during the COVID-19 pandemic

The prevalence of depressive symptoms has increased during the COVID-19 pandemic, especially among those with greater pandemic-related stress exposure; however, not all individuals exposed to pandemic stress will develop depression. Determining which individuals are vulnerable to depressive symptoms as a result of this stress could lead to an improved understanding of the etiology of depression. This study sought to determine whether neural sensitivity to monetary and/or social reward prospectively predicts depressive symptoms during periods of high stress. 121 participants attended pre-pandemic laboratory visits where they completed monetary and social reward tasks while electroencephalogram was recorded. Subsequently, from March to August 2020, we sent eight questionnaires probing depressive symptoms and exposure to pandemic-related stressors. Using repeated-measures multilevel models, we evaluated whether neural response to social or monetary reward predicted increases in depressive symptoms across the early course of the pandemic. Furthermore, we examined whether neural response to social or monetary reward moderated the association between pandemic-related episodic stressors and depressive symptoms. Pandemic-related stress exposure was strongly associated with depressive symptoms. Additionally, we found that blunted neural response to social but not monetary reward predicted increased depressive symptoms during the pandemic. However, neither neural response to social nor monetary reward moderated the association between episodic stress exposure and depressive symptoms. Our findings indicate that neural response to social reward may be a useful predictor of depressive symptomatology under times of chronic stress, particularly stress with a social dimension.

Rethinking the risk for depression using the RDoC: A psychophysiological perspective

Considering that the classical categorical approach to mental disorders does not allow a clear identification of at-risk conditions, the dimensional approach provided by the Research Domain Criteria (RDoC) is useful in the exploration of vulnerability to psychopathology. In the RDoC era, psychophysiological models have an important role in the reconceptualization of mental disorders. Indeed, progress in the study of depression vulnerability has increasingly been informed by psychophysiological models. By adopting an RDoC lens, this narrative review focuses on how psychophysiological models can be used to advance our knowledge of the pathophysiological mechanisms underlying depression vulnerability. Findings from psychophysiological research that explored multiple RDoC domains in populations at-risk for depression are reviewed and discussed. Future directions for the application of psychophysiological research in reaching a more complete understanding of depression vulnerability and, ultimately, improving clinical utility, are presented.

Brain network changes in adult victims of violence

Introduction

Stressful experiences such as violence can affect mental health severely. The effects are associated with changes in structural and functional brain networks. The current study aimed to investigate brain network changes in four large-scale brain networks, the default mode network, the salience network, the fronto-parietal network, and the dorsal attention network in self-identified victims of violence and controls who did not identify themselves as victims.

Materials and methods

The control group (n = 32) was matched to the victim group (n = 32) by age, gender, and primary psychiatric disorder. Sparse inverse covariance maps were derived from functional resting-state measurements and from T1 weighted structural data for both groups.

Results

Our data underlined that mostly the salience network was affected in the sample of self-identified victims. In self-identified victims with a current psychiatric diagnosis, the dorsal attention network was mostly affected underlining the potential role of psychopathological alterations on attention-related processes.

Conclusion

The results showed that individuals who identify themselves as victim demonstrated significant differences in all considered networks, both within- and between-network.

Pathways to depression: Dynamic associations between neural responses to appetitive cues in the environment, stress, and the development of illness

This review focuses on research my colleagues and I have conducted on etiological pathways to depression. Much of this work has focused on the measurement of neural responses to appetitive cues, using two event-related brain potential (ERP) components, the Late Positive Potential (LPP) and the Reward Positivity (RewP). Reductions in each of these components have been associated with current symptoms of depression, and in some cases have been shown to differentiate anxious from depressive phenotypes. In this review, I will describe three broad and related approaches we have taken in our research to address a series of interdependent issuess. The first attempts to understand different sources of variation in the LPP and RewP, and how these sources interact with one another. The second tries to identify whether variation in the processes measured by these ERP components might reflect a latent vulnerability to depression and its symptoms, that is evident prior to illness onset. And the third examines the possibility that the processes reflected in the LPP and RewP might play a mechanistic role in the development of depression.

The association between peer-victimisation and structural and functional brain outcomes: A systematic review

Background

Peer adversity and aggression are common experiences in childhood and adolescence which lead to poor mental health outcomes. To date, there has been no review conducted on the neurobiological changes associated with relational peer-victimisation, bullying and cyberbullying.

Methods

This systematic review assessed structural and functional brain changes associated with peer-victimisation, bullying, and cyberbullying from 1 January 2000 to April 2021. A systematic search of Psychoinfo, Pubmed, and Scopus was performed independently by two reviewers using predefined criteria. Twenty-six studies met the selection criteria and were considered for review.

Results

The data collected shows altered brain activation of regions implicated in processing reward, social pain, and affect; and heightened sensitivity and more widespread activation of brain regions during acute social exclusion, most notably in the amygdala, left parahippocampal gyrus, and fusiform gyrus, associated with victimisation exposure. In addition, victimised youths also demonstrated greater risk-taking behaviours following acute social exclusion showing greater ventral striatum-inferior frontal gyrus coupling, activation in the bilateral amygdala, orbital frontal cortex (OFC), medial prefrontal cortex (MPFC), temporoparietal junction (TPJ), medial posterior parietal cortex (MPPC) and dorsomedial prefrontal cortex (dmPFC), suggesting greater social monitoring, seeking of inclusion, and more effortful cognitive control. The studies included participants from a very broad developmental age range, mostly using cross-sectional measure of peer-victimisation exposure, at varying developmental stages.

Conclusions

This review highlights the need for more neuroimaging studies in cyberbullying, as well as longitudinal studies across more diverse samples for investigating gender, age, and developmental interactions with peer-victimising. This also brings to attention the importance of addressing bullying victimisation particularly in adolescence, given the evidence for social stress in heightening developmentally sensitive processes which are associated with depression, anxiety, and externalising symptoms.

Environmental Contributions to Anhedonia

Anhedonia is a core feature of psychopathological conditions that have recent exposure to stress and trauma as central to their etiology. Indeed, evolutionary accounts of depression suggest that decreased motivation to pursue reward may be an adaptive strategy in the face of social stress, in particular, as it may serve to defuse interpersonal conflict. Through a review of rodent models and research with humans, we show that exposure to stress, particularly when it is chronic, repeated, and/or involves themes of social rejection or defeat, is consistently associated with reduced hedonic capacity ("liking"), motivation to pursue reward ("wanting"), and ability to learn from reward ("reward learning"). Further, across rodent and human research, there is evidence that females show greater stress-induced blunting of reward processing than males. In humans, this sex difference emerges most strongly when examining individual differences in the stress response rather than group differences in stress exposure. We discuss the implications of these findings for understanding the etiology of, and sex differences in, stress-related psychopathology, including depression and addiction.

Neurobiological correlates of the social and emotional impact of peer victimization: A review

Peer victimization is very common during late childhood and adolescence. Despite the relatively reduced number of studies, the neurobiological underpinnings of the negative impact of peer victimization experiences have received increasing attention in recent years. The present selective review summarizes the most recent available evidence and provides a general overview of the impact of peer victimization experiences on social processing and decision-making at the neurobiological level, highlighting the most pressing areas requiring further research. Three key cognitive areas show a clear negative impact of peer victimization and bullying experiences: social valuation processing, reward and reinforcement learning and self-regulation processes. Victims show enhanced activation in key regions of the limbic system including the amygdala, rostral and dorsal anterior cingulate cortices, suggestive of enhanced sensitivity to social stimuli. They also show enhanced recruitment of lateral prefrontal regions crucially involved in cognitive and emotional regulation processes, and abnormal reward-related striatal function. The presence of psychopathology is a complex factor, increased as a consequence of peer victimization, but that also constitutes vulnerability to such experiences.

Developmental trajectories to reduced activation of positive valence systems: A review of biological and environmental contributions

Reduced activation of positive valence systems (PVS), including blunted neural and physiological responses to pleasant stimuli and rewards, has been shown to prospectively predict the development of psychopathology. Yet, little is known about how reduced PVS activation emerges across development or what implications it has for prevention. We review genetic, temperament, parenting, and naturalistic and laboratory stress research on neural measures of PVS and outline developmentally-informed models of trajectories of PVS activation. PVS function is partly heritable and appears to reflect individual differences in early-emerging temperament traits. Although lab-induced stressors blunt PVS activation, effects of parenting and naturalistic stress on PVS are mixed and depend on the type of stressor, developmental timing, and interactions amongst risk factors. We propose that there may be multiple, dynamic developmental trajectories to reduced PVS activation in which combinations of genes, temperament, and exposure to severe, prolonged, or uncontrollable stress may exert direct and interactive effects on PVS function. Critically, these risk factors may alter PVS developmental trajectories and/or PVS sensitivity to proximal stressors. Distinct factors may converge such that PVS activation proceeds along a typical, accelerated, chronically low, or stress-reactive trajectory. Finally, we present directions for future research with translational implications.

Peer Victimization and Dysfunctional Reward Processing: ERP and Behavioral Responses to Social and Monetary Rewards

Peer victimization (or bullying) is a known risk factor for depression, especially among youth. However, the mechanisms connecting victimization experience to depression symptoms remains unknown. As depression is known to be associated with neural blunting to monetary rewards, aberrant responsiveness to social rewards may be a key deficit connecting socially stressful experiences with later depression. We, therefore, sought to determine whether adolescents’ experiences with social stress would be related to their current response to social rewards over less socially relevant monetary rewards. Neural responses to monetary and social rewards were measured using event-related potentials (ERPs) to peer acceptance and rejection feedback (Island Getaway task) and to monetary reward and loss feedback (Doors task) in a sample of 56 late adolescents/emerging young adults followed longitudinally since preschool. In the Island Getaway task, participants voted whether to “keep” or “kick out” each co-player, providing an index of prosocial behavior, and then received feedback about how each player voted for the participant. Analyses tested whether early and recent peer victimization was related to response to rewards (peer acceptance or monetary gains), residualized for response to losses (peer rejection or monetary losses) using the reward positivity (RewP) component. Findings indicated that both experiencing greater early and greater recent peer victimization were significantly associated with participants casting fewer votes to keep other adolescents (“Keep” votes) and that greater early peer victimization was associated with reduced neural response to peer acceptance. Early and recent peer victimization were significantly more associated with neural response to social than monetary rewards. Together, these findings suggest that socially injurious experiences such as peer victimization, especially those occurring early in childhood, relate to two distinct but important findings: that early victimization is associated with later reduced response to peer acceptance, and is associated with later tendency to reject peers. Findings also suggest that there is evidence of specificity to reward processing of different types; thus, future research should expand studies of reward processing beyond monetary rewards to account for the possibility that individual differences may be related to other, more relevant, reward types.