Neural Response to Rewards, Stress and Sleep Interact to Prospectively Predict Depressive Symptoms in Adolescent Girls

Multiple risk markers for increases in depression symptoms across two years: Evidence from the reward positivity and the error-related negativity

BACKGROUND

Both a blunted Reward Positivity (RewP) and Error-Related Negativity (ERN) have been associated with depression. Associations between these neural markers and depression have been observed cross-sectionally, but evidence that they can prospectively predict the development of, or increases in, symptoms of depression is more limited.

METHOD

In this study, we collected EEG data from 157 young adults at a baseline visit (T1), using the Doors and Flanker Tasks to elicit the RewP and the ERN respectively. Participants also reported on symptoms of depression at T1, and multiple times across two academic years (T2 - T8).

RESULTS

Using a multilevel model with the RewP and the ERN as predictors, we found that the RewP predicted future symptoms of depression, while controlling for symptoms of depression at T1, such that a blunted RewP at baseline predicted higher depressive symptoms later. In our data, however, the ERN was not a significant predictor of increases in depression symptoms.

CONCLUSIONS

These findings replicate previous work showing the RewP prospectively predicted increases in depression, and further suggest the specificity of this association. Results support the utility of the RewP as a neurophysiological marker that can help clarify the etiology of depression and inform treatment planning.

Adolescent predictors of substance use in young adulthood among individuals with childhood-onset chronic pain: A follow-up study

BACKGROUND

Adolescent chronic pain is a substantial public health problem, and pain symptoms often persist into adulthood. Young adults with chronic pain are at elevated risk for more frequent tobacco, alcohol and cannabis use, and cross-sectional research highlights the importance of psychosocial vulnerability factors. Limited research has examined how adolescent predictors, including mental health symptoms, pain, sleep and family functioning, impact later, young adult substance use.

METHODS

A prospective cohort of 229 young adults (77.3% female; Mage = 21.0, SD = 1.6) with childhood-onset chronic pain completed measurements in adolescence and a follow-up assessment in young adulthood of past 3-month substance use frequency.

RESULTS

Adolescent sleep quality and male sex were associated with more frequent tobacco use; adolescent depression was associated with more frequent alcohol use, and adolescent pain severity was associated with less frequent, and male sex was associated with more frequent cannabis use.

CONCLUSIONS

Adolescent predictors of young adult substance use among youth with childhood-onset chronic pain represent important factors that may inform assessment, prevention and treatment of substance use in this population. Identifying and testing psychological interventions that target these vulnerability factors may reduce overall substance use risk in young adulthood.

SIGNIFICANCE

This prospective observational study of young adults with childhood-onset chronic pain identified adolescent depression and sleep quality as vulnerability factors associated with substance use. Given the increasing risk for substance use during adolescence and young adulthood, these findings highlight the potential importance of early intervention to reduce substance use among young adults with childhood-onset chronic pain.

Reward-Related Brain Activity Mediates the Relationship Between Decision-Making Deficits and Pediatric Depression Symptom Severity

BACKGROUND

The mechanisms that link neural and behavioral indices of reduced reward sensitivity in depression, particularly in children, remain unclear. Reward positivity (RewP), a neural index of reward processing, has been consistently associated with depression. Separately, recent studies using the drift-diffusion model on behavioral data have delineated computational indices of reward sensitivity. Therefore, in the current study, we examined whether RewP is a neural mediator of drift-diffusion model-based indices of reward processing in predicting pediatric depression across varying levels of symptom severity.

METHODS

A community sample of 166 girls, ages 8 to 14 years, completed 2 tasks. The first was a reward guessing task from which RewP was computed using electroencephalography; the second was a probabilistic reward-based decision-making task. On this second task, drift-diffusion model analysis was applied to behavioral data to quantify the efficiency of accumulating reward-related evidence (drift rate) and potential baseline bias (starting point) toward the differently rewarded choices. Depression severity was measured using the self-report Children's Depression Inventory.

RESULTS

RewP was correlated with drift rate, but not starting point bias, toward the more rewarded choice. Furthermore, RewP completely mediated the association between a slower drift rate toward the more rewarded option and higher depression symptom severity.

CONCLUSIONS

Our findings suggest that reduced neural sensitivity to reward feedback may be a neural mechanism that underlies behavioral insensitivity to reward in children and adolescents with higher depression symptom severity, offering novel insights into the relationship between neural and computational indices of reward processing in this context.

Reduced reward responsiveness and depression vulnerability: Consideration of social contexts and implications for intervention

Depression is a prevalent, heterogeneous, and debilitating disorder that often emerges in adolescence, and there is a need to better understand vulnerability processes to inform more targeted intervention efforts. Psychophysiological methods, like event-related potentials (ERPs), can offer unique insights into the cognitive and emotional processes underlying depression vulnerability. I review my and others' research examining ERP measures of reward responsiveness in youth depression and present a conceptual model of the development of low reward responsiveness, its role in depression vulnerability, and potential windows for targeted intervention. There is evidence that a blunted reward positivity (RewP) is observable in children at risk for depression, appears to be shaped in part by early social experiences, and predicts later depressive symptoms in combination with other risk factors like stress exposure. Further, a component consistent with RewP is reliably elicited in response to social acceptance feedback in computerized peer interaction tasks and demonstrates unique associations with social contextual factors and depressive symptoms, supporting the utility of developing psychophysiological tasks that may better capture youths' real-world experiences and social risk processes. In addition, I address the translational implications of clinical psychophysiological research and describe a series of studies showing that a reduced RewP predicts greater reductions in depressive symptoms with treatment but is not modifiable by current treatments like cognitive behavioral therapy. Finally, I describe our preliminary efforts to develop a positive emotion-focused intervention for the offspring of depressed mothers, informed by the RewP literature, and describe future directions for translating psychophysiological research to intervention and prevention.

Childhood anhedonia symptoms and stressful life events predict the development of reward-related brain activity across adolescence

The reward positivity (RewP) is an event-related potential that indexes reinforcement learning and reward system activation. The RewP has been shown to increase across adolescence; however, most studies have examined the RewP across two assessments, and no studies have examined within-person changes across adolescence into young adulthood. Moreover, the RewP has been identified as a neurobiological risk factor for adolescent-onset depression, but it is unclear whether childhood psychosocial risk factors might predict RewP development across adolescence. In a sample of 317 8- to 14-year-old girls (Mage = 12.4, SD = 1.8), the present study examined self-report measures of depression symptoms and stressful life events at baseline and the ΔRewP during the doors guessing task across three timepoints. Growth modeling indicated that, across all participants, the ΔRewP did not demonstrate linear change across adolescence. However, baseline anhedonia symptoms predicted within-person changes in the ΔRewP, such that individuals with low anhedonia symptoms demonstrated a linear increase in the ΔRewP, but individuals with high anhedonia symptoms had no change in the ΔRewP across adolescence. Similar patterns were observed for stressful life events. The present study suggests that childhood risk factors impact the development of reward-related brain activity, which might subsequently increase risk for psychopathology.

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.

Behavioral and psychiatric correlates of brain responses to social feedback

Maladaptive responses to peer acceptance and rejection arise in numerous psychiatric disorders in adolescence; yet, homogeneity and heterogeneity across disorders suggest common and unique mechanisms of impaired social function. We tested the hypothesis that social feedback is processed similarly to other forms of feedback (e.g., monetary) by examining the correspondence between the brain's response to social acceptance and rejection and behavioral performance on a separate reward and loss task. We also examined the relationship between these brain responses and depression and social anxiety severity. The sample consisted of one hundred and thirteen 16-21-year olds who received virtual peer acceptance/rejection feedback in an event-related potential (ERP) task. We used temporospatial principal component analysis and identified a component consistent with the reward positivity (RewP) or feedback negativity (FN). RewP to social acceptance was not significantly related to reward bias or the FN to social rejection related to loss avoidance. The relationship between RewP and depression severity, while nonsignificant, was of a similar magnitude to prior studies. Exploratory analyses yielded a significant relationship between lower socioeconomic status (SES) and blunted RewP and between lower SES and heightened loss avoidance and blunted reward bias. These findings build on prior work to improve our understanding of the function of the brain's response to social feedback, while also suggesting a pathway for further study, whereby poverty leads to depression via social and reward learning mechanisms.

Adolescents' Sexual Orientation and Behavioral and Neural Reactivity to Peer Acceptance and Rejection: The Moderating Role of Family Support

Sexual-minority adolescents frequently endure peer rejection, yet scant research has investigated sexual-orientation differences in behavioral and neural reactions to peer rejection and acceptance. In a community sample of adolescents approximately 15 years old (47.2% female; same-sex attracted: n = 36, exclusively other-sex attracted: n = 310), we examined associations among sexual orientation and behavioral and neural reactivity to peer feedback and the moderating role of family support. Participants completed a social-interaction task while electroencephalogram data were recorded in which they voted to accept/reject peers and, in turn, received peer acceptance/rejection feedback. Compared with heterosexual adolescents, sexual-minority adolescents engaged in more behavioral efforts to ingratiate after peer rejection and demonstrated more blunted neural reactivity to peer acceptance at low, but not medium or high, levels of family support. By using a simulated real-world social-interaction task, these results demonstrate that sexual-minority adolescents display distinct behavioral and neural reactions to peer acceptance and rejection.

Neural response to rewards moderates the within-person association between daily positive events and positive affect during a period of stress exposure

Stress and neural responses to reward can interact to predict psychopathology, but the mechanisms of this interaction are unclear. One possibility is that the strength of neural responses to reward can affect the ability to maintain positive affect during stress. In this study, 105 participants completed a monetary reward task to elicit the reward positivity (RewP), an event-related potential sensitive to rewards. Subsequently, during a stressful period, participants reported on their affect nine times a day and on daily positive and negative events for 10 days. Even during heightened stress, experiencing more positive events was associated with increased positive affect. The RewP significantly moderated this association: Individuals with a larger RewP reported greater increases in positive affect when they experienced more positive events, relative to individuals with a smaller RewP. A blunted RewP might contribute to stress susceptibility by affecting how much individuals engage in positive emotion regulation during stress.

Beyond the RewP: The reward feedback-elicited LPP and its potential associations with perceived stress and internalizing symptoms in late childhood

Internalizing problems increase substantially during late childhood and early adolescence, which are known to be associated with elevated perceived stress as children transition into adolescence. One risk factor that may moderate the stress-symptom association is reward processing. While neurophysiological research in this field has focused on the reward positivity component (RewP) elicited during reward processing, little work has examined the reward feedback-elicited late positive potential (LPP) and its association with internalizing psychopathology. The present study examined the moderating roles of the RewP and feedback-elicited LPP in the relationship between perceived stress and internalizing symptoms in late childhood. A community sample of 115 nine-to-12-year-old children (66 girls, Mean age = 11.00 years, SD = 1.16) completed an EEG version of the reward feedback paradigm, the Doors task, and completed questionnaires on perceived stress and internalizing symptoms. A principal component analysis revealed three temporo-spatial factors that were temporally and spatially analogous to the RewP, anterior LPP, and posterior LPP, respectively. As expected, an enlarged RewP was found towards the win condition compared to the loss condition. We also observed a potentiated LPP towards loss relative to win feedback, which may reflect the evaluation and reappraisal processes following unsuccessful performance (i.e., loss). We did not, however, find significant moderating effects of any ERP components on the stress-symptom association. Our study was first to isolate the feedback-elicited LPP in a reward processing paradigm in children and provide initial evidence on the modulation of the ERP component by task conditions. Future research is warranted to further explore the functional significance of the reward feedback-elicited LPP in association with perceived stress and internalizing psychopathology in youths.

Characterizing positive and negative valence systems function in adolescent depression: An RDoC-informed approach integrating multiple neural measures

Depression is a prevalent, debilitating, and costly disorder that often manifests in adolescence. There is an urgent need to understand core pathophysiological processes for depression to inform more targeted intervention efforts. The Research Domain Criteria (RDoC) Positive Valence Systems (PVS) and Negative Valence Systems (NVS) have both been implicated in depression symptomatology and vulnerability; however, the nature of NVS alterations is unclear across studies, and associations between single neural measures and symptoms are often small in magnitude and inconsistent. The present study advances characterization of depression in adolescence via an innovative data-driven approach to identifying subgroups of PVS and NVS function by integrating multiple neural measures (assessed by electroencephalogram [EEG]) relevant to depression in adolescents oversampled for clinical depression and depression risk based on maternal history (N = 129; 14-17 years old). Results of the k-means cluster analysis supported a two-cluster solution wherein one cluster was characterized by relatively attenuated reward and emotion responsiveness across valences and the other by relatively intact responsiveness. Youth in the attenuated responsiveness cluster reported significantly greater depressive symptoms and were more likely to have major depressive disorder diagnoses than youth in the intact responsiveness cluster. In contrast, associations of individual neural measures with depressive symptoms were non-significant. The present study highlights the importance of innovative neuroscience approaches to characterize emotional processing in depression across domains, which is imperative to advancing the clinical utility of RDoC-informed research.

Reward and Immune Systems in Emotion (RISE) prospective longitudinal study: Protocol overview of an integrative reward-inflammation model of first onset of major depression in adolescence

Background

Depression is associated with a reduced sensitivity to rewards and low reward-related brain function in cortico-striatal circuitry. A separate literature documents elevated peripheral inflammation in depression. Recently, integrated reward-inflammation models of depression have been proposed. These models draw on work indicating that peripheral inflammatory proteins access the brain, where they lower reward responsiveness. This blunted reward responsiveness is proposed to initiate unhealthy behaviors (substance use, poor diet), as well as sleep disruption and stress generation, which further heighten inflammation. Over time, dysregulation in reward responsiveness and immune signaling may synergize in a positive feedback loop, whereby dysregulation in each system exacerbates dysregulation in the other. Project RISE (Reward and Immune Systems in Emotion) provides a first systematic test of reward-immune dysregulation as a synergistic and dynamic vulnerability for first onset of major depressive disorder and increases in depressive symptoms during adolescence.

Methods

This NIMH-funded R01 study is a 3-year prospective, longitudinal investigation of approximately 300 community adolescents from the broader Philadelphia area, United States of America. Eligible participants must be 13-16 years old, fluent in English, and without a prior major depressive disorder. They are being selected along the entire dimension of self-reported reward responsiveness, with oversampling at the low tail of the dimension in order to increase the likelihood of major depression onsets. At Time 1 (T1), T3, and T5, each a year apart, participants complete blood draws to quantify biomarkers of low-grade inflammation, self-report and behavioral measures of reward responsiveness, and fMRI scans of reward neural activity and functional connectivity. At T1-T5 (with T2 and T4 six months between the yearly sessions), participants also complete diagnostic interviews and measures of depressive symptoms, reward-relevant life events, and behaviors that increase inflammation. Adversity history is assessed at T1 only.

Discussion

This study is an innovative integration of research on multi-organ systems involved in reward and inflammatory signaling in understanding first onset of major depression in adolescence. It has the potential to facilitate novel neuroimmune and behavioral interventions to treat, and ideally prevent, depression.

Cumulative lifetime acute stressor exposure interacts with reward responsiveness to predict longitudinal increases in depression severity in adolescence

BACKGROUND

Life stress and blunted reward processing each have been associated with the onset and maintenance of major depressive disorder. However, much of this work has been cross-sectional, conducted in separate lines of inquiry, and focused on recent life stressor exposure, despite the fact that theories of depression posit that stressors can have cumulative effects over the lifespan. To address these limitations, we investigated whether acute and chronic stressors occurring over the lifespan interacted with blunted reward processing to predict increases in depression over time in healthy youth.

METHOD

Participants were 245 adolescent girls aged 8-14 years old (Mage = 12.4, s.d. = 1.8) who were evaluated at baseline and two years later. The reward positivity (RewP), an event-related potential measure of reward responsiveness, was assessed at baseline using the doors task. Cumulative lifetime exposure to acute and chronic stressors was assessed two years later using the Stress and Adversity Inventory for Adolescents (Adolescent STRAIN). Finally, depressive symptoms were assessed at both baseline and follow-up using the Children's Depression Inventory.

RESULTS

As hypothesized, greater lifetime acute stressor exposure predicted increases in depressive symptoms over two years, but only for youth exhibiting a blunted RewP. This interaction, however, was not found for chronic stressors.

CONCLUSIONS

Lifetime acute stressor exposure may be particularly depressogenic for youth exhibiting a blunted RewP. Conversely, a robust RewP may be protective in the presence of greater acute lifetime stressor exposure.

Drinking alcohol by mid-adolescence is related to reduced reward reactivity: Novel evidence of positive valence system alterations in early initiating female youth

Initiation of alcohol use at younger ages is prognostic of later drinking problems. Reward system dysfunction is theorized to contribute to early initiation and escalation of drinking, but existing evidence supports both hyposensitivity and hypersensitivity as risk-markers; research employing effective indices of reward processing is needed for clarification. The reward positivity (RewP) is a well-established neurophysiological index of hedonic "liking," an important aspect of reward processing. Adult research has yielded conflicting findings, with different studies reporting reduced, enhanced, or null associations of RewP with engagement in or risk for harmful alcohol use. No study has examined relations between RewP and multiple indices of drinking in youth. Here, we examined how RewP measured in a gain/loss feedback task related to self-reported drinking initiation and past-month drinking, when accounting for age along with depression and externalizing symptoms, in 250 mid-adolescent females. Analyses showed that (1) compared to not-yet drinkers, adolescents endorsing drinking initiation responded less strongly to monetary gain (RewP) but not loss feedback (FN), and (2) past-month drinking was unrelated to both RewP and FN magnitude. These findings provide evidence for reduced hedonic "liking" as a concomitant of early drinking initiation in adolescent females and warrant further research with mixed-sex adolescent samples exhibiting greater drinking variability.

Prevalence of depressive symptoms and associated factors during the COVID-19 pandemic: A national-based study

BACKGROUND

Previous studies have reported that the prevalence of depression and depressive symptoms was significantly higher than that before the COVID-19 pandemic. This study aimed to explore the prevalence of depressive symptoms and evaluate the importance of influencing factors through Back Propagation Neural Network (BPNN).

METHODS

Data were sourced from the psychology and behavior investigation of Chinese residents (PBICR). A total of 21,916 individuals in China were included in the current study. Multiple logistic regression was applied to preliminarily identify potential risk factors for depressive symptoms. BPNN was used to explore the order of contributing factors of depressive symptoms.

RESULTS

The prevalence of depressive symptoms among the general population during the COVID-19 pandemic was 57.57 %. The top five important variables were determined based on the BPNN rank of importance: subjective sleep quality (100.00 %), loneliness (77.30 %), subjective well-being (67.90 %), stress (65.00 %), problematic internet use (51.20 %).

CONCLUSIONS

The prevalence of depressive symptoms in the general population was high during the COVID-19 pandemic. The BPNN model established has significant preventive and clinical meaning to identify depressive symptoms lay theoretical foundation for individualized and targeted psychological intervention in the future.

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.

The interplay of childhood maltreatment and maternal depression in relation to the reward positivity in youth

Guided by developmental psychopathology and dual-risk frameworks, the present study examined the interplay between childhood maltreatment and maternal major depression history in relation to neural reward responsiveness in youth. The sample consisted of 96 youth (ages 9-16; M = 12.29 years, SD = 2.20; 68.8% female) drawn from a large metropolitan city. Youth were recruited based on whether their mothers had a history of major depressive disorder (MDD) and were categorized into two groups: youth with mothers with a history of MDD (high risk; HR; n = 56) and youth with mothers with no history of psychiatric disorders (low risk; LR; n = 40). The reward positivity (RewP), an event-related potential component, was utilized to measure reward responsiveness and the Childhood Trauma Questionnaire measured childhood maltreatment. We found a significant two-way interaction between childhood maltreatment and risk group in relation to RewP. Simple slope analysis revealed that in the HR group, greater childhood maltreatment was significantly associated with reduced RewP. The relationship between childhood maltreatment and RewP was not significant among the LR youth. The present findings demonstrate that the association between childhood maltreatment and blunted reward responsiveness is dependent on whether offspring have mothers with histories of MDD.

Error-related brain activity in pediatric major depressive disorder: An ERP and time-frequency investigation

BACKGROUND

The error-related negativity (ERN) reflects individual differences in error monitoring. However, findings on the ERN in adult and adolescent depression have been inconsistent. Analyzing electroencephalographic (EEG) data in both the time- and time-frequency domain can be useful to better quantify neural response to errors. The present study aimed at examining electrocortical measures of error monitoring in early adolescents with and without depression.

METHOD

EEG activity was collected during an arrowhead version of the flanker task in 29 (25 females) early adolescents with depression and 34 without MDD (29 females).

RESULTS

The depression group showed reduced ERN amplitude, reduced error-related theta power and increased error-related beta power compared to the control group. When all variables that related to MDD diagnosis were considered simultaneously, both theta and beta power, but not the ERN, were independently related to an increased likelihood of being diagnosed with depression.

CONCLUSIONS

By examining both time-domain and separate time-frequency measures, the present study provided novel evidence on error monitoring alterations in youth depression, suggesting that depression during adolescence may be characterized by reduced error monitoring (i.e., reduced ERN and error-related theta) and post-error inhibition (i.e., greater error-related beta power). These results support that time-frequency measures might be better suited for examining error-related neural activity in MDD relative to time-domain measures.

Advances in stress and depression research

PURPOSE OF REVIEW

Stress plays a central role in the onset and course of depression. However, only a subset of people who encounter stressful life events go on to experience a depressive episode. The current review highlights recent advances in understanding when, why, and for whom the stress-depression link occurs, and we identify avenues for future research.

RECENT FINDINGS

In the last 18 months, researchers have taken a more nuanced perspective on the biopsychosocial mechanisms critical to the stress-depression link. For example, examination of specific facets of emotion regulation, including emotion regulation flexibility and interpersonal emotion regulation, has been critical to understanding its role in depression. Similarly, refined investigations of social support allowed researchers to identify distinct - and occasionally opposite - outcomes depending on the context or manner in which the support was provided. Researchers also documented that the stress-depression link was enhanced by dysregulation of several stress-sensitive biological systems, such as the immune system, microbiome, endocrine system, and neuroanatomical substrates.

SUMMARY

Recent studies highlight the importance of adopting a nuanced understanding of mechanisms and moderators that explain the stress-depression link. We also encourage continued engagement in collaborative, open science that uses multiple methods to study the full breadth of human diversity.

Associations between parental conflict and social and monetary reward responsiveness in adolescents with clinical depression

Increased rates of depression beginning in adolescence are thought to be attributed in part to marked developmental changes in reward systems and interpersonal relationships. Blunted reward response has been observed in depression and this may be shaped in part by social experiences, raising questions about the combined associations of parental conflict, depression, and reward response in both social and monetary domains. The present study used the reward positivity (RewP), an event-related potential that indexes both monetary and social reward processing, to examine the unique and combined associations of parental conflict and depressive symptoms on reward responsiveness in adolescents with clinical depression (N = 70) 14-18 years of age (M = 15.81, SD = 1.46; 65.7% female). Results indicated that depressive symptoms interacted with maternal conflict in characterizing the RewP to social, but not monetary, rewards. Specifically, higher levels of current depressive symptoms and potentiated maternal conflict together were associated with an attenuated RewP to social rewards in this clinical sample. We found no significant effects of paternal conflict. This investigation highlights maternal conflict as an important environmental factor for reward responsiveness and also emphasizes the utility of examining social reward responsiveness in depression in order to better understand the impacts of contextual factors.

Blunted reward responsiveness prospectively predicts emotional distress when exposed to a naturalistic stressor

Both stress and blunted reward responsiveness have been identified as core risk factors of depression. Whether blunted reward responsiveness increases psychological vulnerability to real-life stress from a dynamic perspective (from stress reactivity to recovery) has not been investigated. By utilizing a real-world stressful event (i.e. the final examination), this study aimed to explore the role of reward responsiveness in the stress-emotional distress relationship during stress reactivity and recovery phases. We followed 57 undergraduates with three assessments, from six weeks before examination weeks (T1, baseline), one day before the examinations (T2) to two weeks after the examinations (T3), therefore, covering stress reactivity (T1 to T2) and recovery (T2 to T3) phases. At baseline, reward responsiveness was measured as the Reward Positivity (RewP) in the doors task. Stress and emotional distress (anxiety and depression) were reported at T1, T2 and T3 to capture their dynamic changes. Results showed that self-report stress levels significantly increased from T1 to T2 (stress reactivity phase) and decreased from T2 to T3 (stress recovery phase). Furthermore, blunted reward responsiveness at baseline prospectively predicted emotional distress during the stress reactivity phase but not the recovery phase. Specifically, during the stress reactivity phase, higher perceived stress was associated with greater anxiety and depression only in participants with relatively smaller residual RewP amplitudes but not in participants with relatively larger residual RewP amplitudes. Our study demonstrated that a blunted reward responsiveness is a vulnerable factor of depression, especially when exposed to stress. Our findings provide insights into prevention and intervention for stress-related disturbance.

Greater Cumulative Lifetime Stressor Exposure Predicts Blunted Reward Positivity in Adolescent Girls Followed for 2 Years

BACKGROUND

Although research has found that life stress is associated with reward-related brain activity, few studies have examined how cumulative stressors occurring over the entire lifetime affect reward processing during adolescence.

METHODS

To address this issue, we investigated how lifetime stressor exposure related to reward processing, indexed by the reward positivity, in 240 adolescent girls between ages 8 and 14 years (mean age = 12.4). Participants were followed for 2 years. They completed a reward task at baseline and follow-up and the Stress and Adversity Inventory at follow-up.

RESULTS

As hypothesized, greater lifetime stressor exposure was related to a blunted reward positivity at the follow-up session while controlling for baseline age, baseline reward positivity, and time between assessments. Furthermore, this association was evident for acute but not chronic lifetime stressors.

CONCLUSIONS

These data suggest that the development of adaptive reward processing may be adversely affected by experiencing major life stressors. The results may thus have implications for understanding how stressors increase risk for psychopathology, such as major depressive disorder.

Increases in depression and anxiety symptoms in adolescents and young adults during the COVID-19 pandemic

BACKGROUND

The coronavirus [coronavirus disease 2019 (COVID-19)] pandemic has introduced extraordinary life changes and stress, particularly in adolescents and young adults. Initial reports suggest that depression and anxiety are elevated during COVID-19, but no prior study has explored changes at the within-person level. The current study explored changes in depression and anxiety symptoms from before the pandemic to soon after it first peaked in Spring 2020 in a sample of adolescents and young adults (N = 451) living in Long Island, New York, an early epicenter of COVID-19 in the U.S.

METHODS

Depression (Children's Depression Inventory) and anxiety symptoms (Screen for Child Anxiety Related Symptoms) were assessed between December 2014 and July 2019, and, along with COVID-19 experiences, symptoms were re-assessed between March 27th and May 15th, 2020.

RESULTS

Across participants and independent of age, there were increased generalized anxiety and social anxiety symptoms. In females, there were also increased depression and panic/somatic symptoms. Multivariable linear regression indicated that greater COVID-19 school concerns were uniquely associated with increased depression symptoms. Greater COVID-19 home confinement concerns were uniquely associated with increased generalized anxiety symptoms, and decreased social anxiety symptoms, respectively.

CONCLUSIONS

Adolescents and young adults at an early epicenter of the COVID-19 pandemic in the U.S. experienced increased depression and anxiety symptoms, particularly amongst females. School and home confinement concerns related to the pandemic were independently associated with changes in symptoms. Overall, this report suggests that the COVID-19 pandemic is having multifarious adverse effects on the mental health of youth.

Manipulating Reward Sensitivity Using Reward Circuit-Targeted Transcranial Magnetic Stimulation

BACKGROUND

The reward circuit is important for motivation and learning, and dysregulations of the reward circuit are prominent in anhedonic depression. Noninvasive interventions that can selectively target the reward circuit may hold promise for the treatment of anhedonia.

METHODS

We tested a novel transcranial magnetic stimulation intervention for modulating the reward circuit. A total of 35 healthy individuals participated in a crossover controlled study targeting the reward circuit or a control site with intermittent theta burst stimulation (iTBS), an excitatory form of transcranial magnetic stimulation. Individual reward circuit targets were defined based upon functional magnetic resonance imaging functional connectivity with the ventral striatum, yielding targets in the rostromedial prefrontal cortex (rmPFC). Reward circuit function was assessed at baseline using functional magnetic resonance imaging, and reward circuit modulation was assessed using an event-related potential referred to as the reward positivity, which has been shown to reliably track reward sensitivity, as well as individual differences in depression and risk for depression.

RESULTS

Relative to control iTBS, rmPFC iTBS enhanced the reward positivity. This effect was moderated by reward function, suggesting greater enhancements in individuals with lower reward function. This effect was also moderated by rmPFC-ventral striatum connectivity insofar as iTBS reached the rmPFC, suggesting that efficacy relies jointly on the strength of the rmPFC-ventral striatum pathway and ability of transcranial magnetic stimulation to target the rmPFC.

CONCLUSIONS

These data suggest that the reward circuit can be modulated by rmPFC iTBS, and amenability to such modulations is related to measures of reward circuit function. This provides the first step toward a novel noninvasive treatment of disorders of the reward circuit.

Understanding Trajectories to Anxiety and Depression: Neural Responses to Errors and Rewards as Indices of Susceptibility to Stressful Life Events

Between-individuals variation in neural responses to errors and rewards is associated with the degree of risk for developing depression and anxiety, but not all individuals with perturbations in systems that generate these responses go on to develop symptoms. We propose that exposure to stressful life events may determine when these individual differences in neural responses to errors and rewards result in anxiety or depression. In this article, we review key findings and discuss limitations and questions in research on how stressors interact with reward and error processing to predict the development of symptoms. We conclude by outlining future research directions.

Depressive Symptoms Prospectively Predict Peer Victimization: A Longitudinal Study Among Adolescent Females

Research has consistently demonstrated a relationship between peer victimization, a major issue in early adolescence, and depression. However, longitudinal studies examining the relationship between peer victimization and depressive symptoms have yielded mixed results. Thus, the current study examined how specific aspects of peer victimization and subtypes of depressive symptoms are related over a two-year period. Adolescent females (N = 265) completed a questionnaire battery at baseline and two-year follow-up. Results indicated that baseline depressive symptoms prospectively predict peer overt victimization, relational victimization, and decreased prosocial behaviors at follow-up; baseline peer victimization did not predict depressive symptoms at follow-up. Further, results demonstrate the differential predictive value of specific depressive symptoms for overt vs. relational aggression and decreased prosocial behavior. Taken together, this study provides insight into the impact of depressive symptoms on peer victimization and the importance of addressing peer relations in the context of treatment for adolescent depression.

Abnormal functional connectivity of the anterior cingulate cortex subregions mediates the association between anhedonia and sleep quality in major depressive disorder

BACKGROUND

The anterior cingulate cortex (ACC) is a crucial region in the pathophysiology of major depressive disorder (MDD). However, the relationship between functional alterations of the ACC subregions, anhedonia and sleep quality remains unclear in MDD patients.

METHODS

The resting-state functional connectivity (rsFC) of ACC subregions was measured in 41 first-episode medication-naïve MDD patients and 63 healthy controls who underwent functional magnetic resonance imaging. Between-group differences were examined using two-sample t-test. Furthermore, correlation and mediation analyses were carried out to investigate the relationships between the aberrant rsFC of ACC subregions, anhedonia and sleep quality in the patients and controls.

RESULTS

Compared to healthy controls, the MDD patients exhibited increased rsFC of ACC subregions to areas of the anterior default mode network (DMN) and showed decreased rsFC of the right subgenual ACC to left precuneus (PCUN), which belongs to the posterior DMN. In MDD group, the sleep quality and consummatory anhedonia are correlated with some rsFC, which involves the angular gyrus (ANG) and superior frontal gyrus (SFG). More importantly, the rsFC between the right perigenual ACC and left SPG mediates the association between anhedonia and sleep quality in MDD.

LIMITATIONS

The cross-sectional design and the subjective questionaries for assessment.

CONCLUSION

These findings confirm the functional alterations of the ACC subregions and reveal the mediating role of ACC subregions in sleep and reward dysfunction in MDD.

In the Face of Potential Harm: The Predictive Validity of Neural Correlates of Performance Monitoring for Perceived Risk, Stress, and Internalizing Psychopathology During the COVID-19 Pandemic

Background

The COVID-19 pandemic is a major life stressor posing serious threats not only to physical but also to mental health. To better understand mechanisms of vulnerability and identify individuals at risk for psychopathological symptoms in response to stressors is critical for prevention and intervention. The error-related negativity (ERN) has been discussed as a neural risk marker for psychopathology, and this study examined its predictive validity for perceived risk, stress, and psychopathological symptoms during the COVID-19 pandemic.

Methods

A total of 113 individuals who had participated as healthy control participants in previous electroencephalography studies (2014–2019) completed a follow-up online survey during the first COVID-19 wave in Germany. Associations of pre-pandemic ERN and correct-response negativity (CRN) with perceived risk regarding COVID-19 infection, stress, and internalizing symptoms during the pandemic were examined using mediation models.

Results

Pre-pandemic ERN and CRN were associated with increased perceived risk regarding a COVID-19 infection. Via this perceived risk, the ERN and CRN were associated with increased stress during the pandemic. Furthermore, risk perception and stress mediated indirect effects of ERN and CRN on internalizing psychopathology, including anxiety, depression, and obsessive-compulsive symptoms, while controlling for the effects of pre-pandemic symptom levels.

Conclusions

In summary, heightened pre-pandemic performance monitoring showed indirect associations with increases in psychopathological symptoms during the first COVID-19 wave via effects on perceived COVID-19 risk and stress. These results further strengthen the notion of performance monitoring event-related potentials as transdiagnostic neural risk markers and highlight the relevance of stress as a catalyst for symptom development.

Acute stress reduces reward-related neural activity: Evidence from the reward positivity

Stress and blunted reward processing are risk factors for Major Depressive Disorder (MDD). The experience of acute stress reduces fMRI correlates of reward-related neural activity; however, few studies have examined how acute stress impacts measures of reward derived from event-related potentials (ERPs). The current study examined the impact of an acute stressor on the Reward Positivity (RewP), an ERP that indexes reward sensitivity, in twenty-six college students. Participants completed a monetary reward task while they placed their left hand in cold water set at 13 °C (i.e. acute stress condition) and again while their hand was placed in room temperature water (i.e. control condition). These conditions were separated by one week and performed in a counter-balanced order across participants. The results revealed that the RewP amplitude was blunted in the acute stress condition compared to the control condition. Moreover, there was a trend toward this effect interacting with self-reported depressive symptoms: the RewP was reduced only among individuals who reported low depressive symptoms. The current study suggests that an acute stressor reduces the RewP, and that this effect might be moderated by current depressive symptoms. Future studies might examine the temporal association between reward processing and stress, and how they interact to predict depressive symptoms.LAY SUMMARYThe current study examined the impact of acute stress on the brain's reward system. The results indicated that acute stress reduced activity within the brain's reward system, particularly among individuals with low depressive symptoms.

Maternal suicidality interacts with blunted reward processing to prospectively predict increases in depressive symptoms in 8-to-14-year-old girls

Both a hypoactive reward system and maternal depression are associated with the onset of Major Depressive Disorder (MDD) in youth. Recent research indicates that blunted reward processing and maternal history of depression may interact to predict increases in depressive symptoms, however, the role of specific maternal depressive symptoms has not been examined. The current study investigated whether maternal depressive symptoms, history of MDD, and suicidal thoughts and/or behaviors (STBs) might lead to prospective increases in depressive symptoms one year later in the context of hypoactive reward processing. In a sample (N = 212) of 8 to 14-year-old girls, we assessed depressive symptoms in youth at baseline and follow up, while reward processing was measured using the Reward Positivity (RewP) event-related brain potential. Maternal STBs, current depressive symptoms, and history of maternal MDD were assessed at baseline. The results indicated that only girls with a blunted RewP and maternal STBs exhibited increased depressive symptoms one year later. These results were not evident when maternal depressive symptoms or maternal history of MDD was examined as the moderator. Overall, the current study provides evidence that maternal STBs uniquely impact youth with blunted reward processing.

Neural Response to Rewards in Youths with Insomnia

STUDY OBJECTIVES

Insomnia and depression are common comorbid conditions in youths. Emerging evidence suggests that disrupted reward processing may be implicated in the association between insomnia and the increased risk for depression. Reduced reward positivity (RewP) as measured by event-related potential (ERP) has been linked to depression, but has not been tested in youths with insomnia.

METHODS

Twenty-eight participants with insomnia disorder and without any comorbid psychiatric disorders and 29 healthy sleepers aged between 15-24 completed a monetary reward task, the Cued Door task, whilst electroencephalographic activity was recorded. RewP (reward minus non-reward difference waves) was calculated as the mean amplitudes within 200ms to 300ms time window at FCz. Two analyses of covariance (ANCOVAs) were conducted with age as a covariate on RewP amplitude and latency, respectively.

RESULTS

Participants with insomnia had a significantly lower RewP amplitude regardless of cue types (Gain, Control, and Loss) than healthy sleepers, F (1, 51) = 4.95, p = .031, indicating blunted reward processing. On the behavioural level, healthy sleepers were more prudential (slower reaction time) in decision making towards Loss/Gain cues than their insomnia counterparts. Trial-by-trial behavioural adjustment analyses showed that, compared with healthy sleepers, participants with insomnia were less likely to dynamically change their choices in response to Loss cues.

CONCLUSIONS

Dysfunctional reward processing, coupled with inflexibility of behavioural adjustment in decision-making, is associated with insomnia disorder among youth, independent of mood disorders. Future studies with long-term follow-up are needed to further delineate the developmental trajectory of insomnia-related reward dysfunctions in youth.

The interplay of stress and electrocortical reactivity to reward in the prospective prediction of depression symptoms during COVID-19

Rates of depression have increased during the novel coronavirus disease 2019 (COVID-19) pandemic, potentially due to associated stress exposure. However, it remains unclear which individuals are most susceptible. Electrocortical markers of reward processing, such as the reward positivity (RewP), are implicated in depression risk and may provide insights into who is most vulnerable to stress during the COVID-19 pandemic. The current study examined whether pre-pandemic neural correlates of reward reactivity (i.e., RewP) moderated the impact of social and financial stress on changes in youth and mother depression symptoms pre-to-post pandemic onset. Youth (n = 45) and mothers (n = 45) in the current sample were recruited prior to the COVID-19 pandemic as part of a larger study. RewP was assessed pre-pandemic, and depression symptoms were assessed pre- and post-pandemic onset for both youth and mothers. Additionally, social and financial chronic stress severity was assessed post-pandemic onset using a modified version of the UCLA Life Stress Interview. Financial stress was associated with prospective increases in depression for youth exhibiting blunted RewP at baseline. Similarly, family stress was associated with prospective increases in depression symptoms for mothers exhibiting blunted RewP at baseline. Findings suggest reduced reward responsiveness at the neural level may predispose both youth and mothers to future depression symptoms when exposed to higher levels of stress in the context of a pandemic.

Associations between insomnia and reward learning in clinical depression

BACKGROUND

Depression and insomnia commonly co-occur. Yet, little is known about the mechanisms through which insomnia influences depression. Recent research and theory highlight reward system dysfunction as a potential mediator of the relationship between insomnia and depression. This study is the first to examine the impact of insomnia on reward learning, a key component of reward system functioning, in clinical depression.

METHODS

The sample consisted of 72 veterans with unipolar depression who endorsed sleep disturbance symptoms. Participants completed the Structured Clinical Interview for DSM-IV, self-report measures of insomnia, depression, and reward processing, and a previously validated signal detection task (Pizzagalli et al., 2005, Biological Psychiatry, 57(4), 319-327). Trial-by-trial response bias (RB) estimates calculated for each of the 200 task trials were examined using linear mixed-model analyses to investigate change in reward learning.

RESULTS

Findings demonstrated diminished rate and magnitude of reward learning in the Insomnia group relative to the Hypersomnia/Mixed Symptom group across the task. Within the Insomnia group, participants with more severe insomnia evidenced the lowest rates of reward learning, with increased RB across the task with decreasing insomnia severity.

CONCLUSIONS

Among individuals with depression, insomnia is associated with decreased ability to learn associations between neutral stimuli and rewarding outcomes and/or modify behavior in response to differential receipt of reward. This attenuated reward learning may contribute to clinically meaningful decreases in motivation and increased withdrawal in this comorbid group. Results extend existing theory by highlighting impairments in reward learning specifically as a potential mediator of the association between insomnia and depression.

Great Expectations: A Critical Review of and Suggestions for the Study of Reward Processing as a Cause and Predictor of Depression

Both human and animal studies support the relationship between depression and reward processing abnormalities, giving rise to the expectation that neural signals of these processes may serve as biomarkers or mechanistic treatment targets. Given the great promise of this research line, we scrutinized those findings and the theoretical claims that underlie them. To achieve this, we applied the framework provided by classical work on causality as well as contemporary approaches to prediction. We identified a number of conceptual, practical, and analytical challenges to this line of research and used a preregistered meta-analysis to quantify the longitudinal associations between reward processing abnormalities and depression. We also investigated the impact of measurement error on reported data. We found that reward processing abnormalities do not reach levels that would be useful for clinical prediction, yet the available evidence does not preclude a possible causal role in depression.

A reduced P300 prospectively predicts increased depressive severity in adults with clinical depression

Neurocognitive impairments commonly observed in depressive disorders are thought to be reflected in reduced P300 amplitudes. To date, depression-related P300 amplitude reduction has mostly been demonstrated cross-sectionally, while its clinical implication for the course of depression remains largely unclear. Moreover, the relationship between P300 and specific clinical characteristics of depression is uncertain. To shed light on the functional significance of the P300 in depression, we examined whether initial P300 amplitude prospectively predicted changes in depressive symptoms among a community sample of 58 adults (mean age = 38.86 years old, 81% female) with a current depressive disorder. This sample was assessed at two-time points, separated by approximately nine months (range = 6.6-15.9). At the initial visit, participants completed clinical interviews, self-report measures, and a flanker task, while EEG was recorded to derive P300 amplitude. At the follow-up visit, participants again completed the same clinical interviews and self-report measures. Results indicated that a reduced P300 amplitude at the initial visit was associated with higher total depressive symptoms at follow-up, even after controlling for initial depressive symptoms. These data indicate the potential clinical utility for the P300 as a neural marker of disease course among adults with a current depressive disorder. Future research may target P300 in interventions to determine whether depression-related outcomes can be improved.

Friendship stability in adolescence is associated with ventral striatum responses to vicarious rewards

An important task for adolescents is to form and maintain friendships. In this three-wave biannual study, we used a longitudinal neuroscience perspective to examine the dynamics of friendship stability. Relative to childhood and adulthood, adolescence is marked by elevated ventral striatum activity when gaining self-serving rewards. Using a sample of participants between the ages of eight and twenty-eight, we tested age-related changes in ventral striatum response to gaining for stable (n = 48) versus unstable best friends (n = 75) (and self). In participants with stable friendships, we observed a quadratic developmental trajectory of ventral striatum responses to winning versus losing rewards for friends, whereas participants with unstable best friends showed no age-related changes. Ventral striatum activity in response to winning versus losing for friends further varied with friendship closeness for participants with unstable friendships. We suggest that these findings may reflect changing social motivations related to formation and maintenance of friendships across adolescence.

An Integrated Sleep and Reward Processing Model of Major Depressive Disorder

Major depressive disorder with comorbid sleep disturbance has been associated with negative outcomes, including lower rates of treatment response and a greater likelihood of depressive relapse compared to those without sleep disturbance. However, little, if any, research has been conducted to understand why such negative treatment outcomes occur when sleep disturbance is present. In this conceptual review, we argue that the relationship of sleep disturbance and negative treatment outcomes may be mediated by alterations in neural reward processing in individuals with blunted trait-level reward responsivity. We first briefly characterize sleep disturbance in depression, discuss the nature of reward processing impairments in depression, and summarize the sleep/reward relationship in healthy human subjects. We then introduce a novel Integrated Sleep and Reward model of the course and maintenance of major depressive disorder and present preliminary evidence of sleep and reward interaction in unipolar depression. Finally, we discuss limitations of the model and offer testable hypotheses and directions for future research.