Reward Processing and Risk for Depression Across Development

Subanesthetic S-ketamine does not acutely alter striatal dopamine transporter binding in healthy Sprague Dawley female rats

Major depressive disorder is one of the most prevalent mental health disorders, posing a global socioeconomic burden. Conventional antidepressant treatments have a slow onset of action, and 30% of patients show no clinically significant treatment response. The recently approved fast-acting antidepressant S-ketamine, an N-methyl-D-aspartate receptor antagonist, provides a new approach for treatment-resistant patients. However, knowledge of S-ketamine's mechanism of action is still being established. Depressed human subjects have lower striatal dopamine transporter (DAT) availability compared to healthy controls. Rodent studies report increased striatal dopamine concentration in response to acute ketamine administration. In vivo [18F]FE-PE2I ([18F]-(E)-N-(3-iodoprop-2-enyl)-2β-carbofluoroethoxy-3β-(4'-methyl-phenyl) nortropane) positron emission tomography (PET) imaging of the DAT has not previously been applied to assess the effect of acute subanesthetic S-ketamine administration on DAT availability. We applied translational in vivo [18F]FE-PE2I PET imaging of the DAT in healthy female rats to evaluate whether an acute subanesthetic intraperitoneal dose of 15 mg/kg S-ketamine alters DAT availability. We also performed [3H]GBR-12935 autoradiography on postmortem brain sections. We found no effect of acute S-ketamine administration on striatal DAT binding using [18F]FE-PE2I PET or [3H]GBR-12935 autoradiography. This negative result does not support the hypothesis that DAT changes are associated with S-ketamine's rapid antidepressant effects, but additional studies are warranted.

Everyday emotion, naturalistic life stress, and the prospective prediction of adolescent depression

BACKGROUND AND OBJECTIVES

Increasing research underscores low positive emotion (PE) as a vital component of depression risk in adolescence. Theory also suggests that PE contributes to adaptive coping. However, it is unclear whether naturalistic experiences of emotions contribute to long-term depression risk, or whether daily PE levels equip adolescents to cope with later naturalistic stressors, reducing risk for depression. The current study examines whether PE (and negative emotion [NE]) assessed via ecological momentary assessment (EMA) (a) predict prospective increases in depression, and (b) moderate the association between later life stressors and depression.

DESIGN

Longitudinal study of community-recruited adolescents, with EMA at baseline.

METHOD

Adolescents (n = 232) completed contextual threat life stress interviews, interview and self-report measures of depression at baseline and 1.5 year follow-up. At baseline, they completed a seven-day EMA of emotion.

RESULTS

Preregistered analyses showed that daily NE, but not PE, predicted increased depression over time and moderated the association between interpersonal episodic stress and self-reported depression.

CONCLUSIONS

Results did not support daily PE as a buffer against depressogenic effects of life stress, but point to daily NE as a marker of depression risk.

Reward-Related Brain Activity Mediates the relationship between Decision-Making Deficits and Pediatric Depression Symptom Severity

BACKGROUND

The mechanisms linking 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 (DDM) on behavioral data have delineated computational indices of reward sensitivity. Therefore, the present study examined whether RewP is a neural mediator of DDM-based indices of reward processing in predicting pediatric depression across varying levels of symptom severity.

METHODS

A community sample of 166 girls, aged 8 to 14 years, completed two 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, DDM analysis was applied to behavioral data to quantify the efficiency of accumulating reward-related evidence (drift rate) and potential baseline bias (starting point) towards the differently rewarded choices. Depression severity was measured using the self-report Children's Depression Inventory (CDI).

RESULTS

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

CONCLUSION

Our findings suggest that reduced neural sensitivity to reward feedback might be a neural mechanism underscoring 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.

Task-Rest Reconfiguration Efficiency of the Reward Network Across Adolescence and Its Association With Early Life Stress and Depressive Symptoms

OBJECTIVE

Adolescents face significant changes in many domains of their daily lives that require them to flexibly adapt to changing environmental demands. To shift efficiently among various goals, adolescents must reconfigure their brains, disengaging from previous tasks and engaging in new activities.

METHOD

To examine this reconfiguration, we obtained resting-state and task-based functional magnetic resonance imaging (fMRI) scans in a community sample of 164 youths. We assessed the similarity of functional connectivity (FC) of the reward network between resting state and a reward-processing state, indexing the degree of reward network reconfiguration required to meet task demands. Given research documenting relations among reward network function, early life stress (ELS), and adolescent depression, we examined the association of reconfiguration efficiency with age across adolescence, the moderating effect of ELS on this association, and the relation between reconfiguration efficiency and depressive symptoms.

RESULTS

We found that older adolescents showed greater reconfiguration efficiency than younger adolescents and, furthermore, that this age-related association was moderated by the experience of ELS.

CONCLUSION

These findings suggest that reconfiguration efficiency of the reward network increases over adolescence, a developmental pattern that is attenuated in adolescents exposed to severe ELS. In addition, even after controlling for the effects of age and exposure to ELS, adolescents with higher levels of depressive symptoms exhibited greater reconfiguration efficiency, suggesting that they have brain states at rest that are more strongly optimized for reward processing than do asymptomatic youth.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science.

The relationship between mental health and risky decision-making in children and adolescents: a scoping review

BACKGROUND

Evidence from studies on adult participants and clinical samples of children suggest an association between risky decision-making and mental health problems. However, the extent and nature of this association in the general youth population remains unknown. Therefore, this scoping review explores the current evidence on the relationship between mental health (internalising and externalising symptoms) and risky decision-making in the general youth population.

METHODS

A three-step search strategy was followed and applied to four databases. Selection criteria included participants < 18 years representative of the general population, and information on both risky decision-making (assessed using gambling tasks) and internalising /externalising symptoms. Data were extracted and synthesised for study and participant characteristics, aspects and measures for the main variables, and key findings.

RESULTS

Following screening, twenty-one studies were retrieved. Non-significant associations were more frequent than significant associations for both internalising and externalising symptoms, particularly for social difficulties and broad externalising symptoms. Among the significant associations, hyperactivity/inattention and conduct problems appeared to be positively associated with risk-taking and negatively associated with quality of decision-making. However, patterns were less clear for links between risky decision-making and internalising symptoms, especially between risk-taking and anxiety symptoms.

CONCLUSIONS

The present review suggests predominantly a lack of relationship between risky decision-making and mental health problems, and outlines several possible reasons for it. However, when specificity is considered carefully there seems to be a link between risk-taking and specific externalising problems. Future research should employ study designs aimed at disentangling the direction of this relationship and identifying specific aspects of mental health and risky decision-making that could be eventually addressed by tailored interventions.

Familial risk for depression moderates neural circuitry in healthy preadolescents to predict adolescent depression symptoms in the Adolescent Brain Cognitive Development (ABCD) Study

BACKGROUND

There is an imminent need to identify neural markers during preadolescence that are linked to developing depression during adolescence, especially among youth at elevated familial risk. However, longitudinal studies remain scarce and exhibit mixed findings. Here we aimed to elucidate functional connectivity (FC) patterns among preadolescents that interact with familial depression risk to predict depression two years later.

METHODS

9-10 year-olds in the Adolescent Brain Cognitive Development (ABCD) Study were classified as healthy (i.e., no lifetime psychiatric diagnoses) at high familial risk for depression (HR; n=559) or at low familial risk for psychopathology (LR; n=1203). Whole-brain seed-to-voxel resting-state FC patterns with the amygdala, putamen, nucleus accumbens, and caudate were calculated. Multi-level, mixed-effects regression analyses were conducted to test whether FC at ages 9-10 interacted with familial risk to predict depression symptoms at ages 11-12.

RESULTS

HR youth demonstrated stronger associations between preadolescent FC and adolescent depression symptoms (ps<0.001) as compared to LR youth (ps>0.001), primarily among amygdala/striatal FC with visual and sensory/somatomotor networks.

CONCLUSIONS

Preadolescent amygdala and striatal FC may be useful biomarkers of adolescent-onset depression, particularly for youth with family histories of depression. This research may point to neurobiologically-informed approaches to prevention and intervention for depression in adolescents.

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.

A distinctive subcortical functional connectivity pattern linking negative affect and treatment outcome in major depressive disorder

Major depressive disorder (MDD) is associated with functional disturbances in subcortical regions. In this naturalistic prospective study (NCT03294525), we aimed to investigate relationships among subcortical functional connectivity (FC), mood symptom profiles and treatment outcome in MDD using multivariate methods. Medication-free participants with MDD (n = 135) underwent a functional magnetic resonance imaging scan at baseline and completed posttreatment clinical assessment after 8 weeks of antidepressant monotherapy. We used partial least squares (PLS) correlation analysis to explore the association between subcortical FC and mood symptom profiles. FC score, reflecting the weighted representation of each individual in this association, was computed. Replication analysis was undertaken in an independent sample (n = 74). We also investigated the relationship between FC score and treatment outcome in the main sample. A distinctive subcortical connectivity pattern was found to be associated with negative affect. In general, higher FC between the caudate, putamen and thalamus was associated with greater negative affect. This association was partly replicated in the independent sample (similarity between the two samples: r = 0.66 for subcortical connectivity, r = 0.75 for mood symptom profile). Lower FC score predicted both remission and response to treatment after 8 weeks of antidepressant monotherapy. The emphasis here on the role of dorsal striatum and thalamus consolidates prior work of subcortical connectivity in MDD. The findings provide insight into the pathogenesis of MDD, linking subcortical FC with negative affect. However, while the FC score significantly predicted treatment outcome, the low odds ratio suggests that finding predictive biomarkers for depression remains an aspiration.

Aberrant reward learning, but not negative reinforcement learning, is related to depressive symptoms: an attentional perspective

BACKGROUND

Aberrant reward functioning is implicated in depression. While attention precedes behavior and guides higher-order cognitive processes, reward learning from an attentional perspective - the effects of prior reward-learning on subsequent attention allocation - has been mainly overlooked.

METHODS

The present study explored the effects of reward-based attentional learning in depression using two separate, yet complimentary, studies. In study 1, participants with high (HD) and low (LD) levels of depression symptoms were trained to divert their gaze toward one type of stimuli over another using a novel gaze-contingent music reward paradigm - music played when fixating the desired stimulus type and stopped when gazing the alternate one. Attention allocation was assessed before, during, and following training. In study 2, using negative reinforcement, the same attention allocation pattern was trained while substituting the appetitive music reward for gazing the desired stimulus type with the removal of an aversive sound (i.e. white noise).

RESULTS

In study 1 both groups showed the intended shift in attention allocation during training (online reward learning), while generalization of learning at post-training was only evident among LD participants. Conversely, in study 2 both groups showed post-training generalization. Results were maintained when introducing anxiety as a covariate, and when using a more powerful sensitivity analysis. Finally, HD participants showed higher learning speed than LD participants during initial online learning, but only when using negative, not positive, reinforcement.

CONCLUSIONS

Deficient generalization of learning characterizes the attentional system of HD individuals, but only when using reward-based positive reinforcement, not negative reinforcement.

Neural Circuit Markers of Familial Risk for Depression Among Healthy Youths in the Adolescent Brain Cognitive Development Study

BACKGROUND

Family history of depression is a robust predictor of early-onset depression, which may confer risk through alterations in neural circuits that have been implicated in reward and emotional processing. These alterations may be evident in youths who are at familial risk for depression but who do not currently have depression. However, the identification of robust and replicable findings has been hindered by few studies and small sample sizes. In the current study, we sought to identify functional connectivity (FC) patterns associated with familial risk for depression.

METHODS

Participants included healthy (i.e., no lifetime psychiatric diagnoses) youths at high familial risk for depression (HR) (n = 754; at least one parent with a history of depression) and healthy youths at low familial risk for psychiatric problems (LR) (n = 1745; no parental history of psychopathology) who were 9 to 10 years of age and from the Adolescent Brain Cognitive Development (ABCD) Study sample. We conducted whole-brain seed-to-voxel analyses to examine group differences in resting-state FC with the amygdala, caudate, nucleus accumbens, and putamen. We hypothesized that HR youths would exhibit global amygdala hyperconnectivity and striatal hypoconnectivity patterns primarily driven by maternal risk.

RESULTS

HR youths exhibited weaker caudate-angular gyrus FC than LR youths (α = 0.04, Cohen's d = 0.17). HR youths with a history of maternal depression specifically exhibited weaker caudate-angular gyrus FC (α = 0.03, Cohen's d = 0.19) as well as weaker caudate-dorsolateral prefrontal cortex FC (α = 0.04, Cohen's d = 0.21) than LR youths.

CONCLUSIONS

Weaker striatal connectivity may be related to heightened familial risk for depression, primarily driven by maternal history. Identifying brain-based markers of depression risk in youths can inform approaches to improving early detection, diagnosis, and treatment.

Sex-Specific Vulnerability to Externalizing Problems: Sensitivity to Early Stress and Nucleus Accumbens Activation Over Adolescence

BACKGROUND

Exposure and sensitivity to early-life stress (ELS) are related to increased risk for psychopathology in adolescence. While cross-sectional studies have reported blunted nucleus accumbens (NAcc) activation in the context of these associations, researchers have not yet assessed the effects of ELS on developmental trajectories of activation. We examined whether trajectories are affected by stress and the moderating role of biological sex in predicting vulnerability to symptoms of psychopathology.

METHODS

Adolescents (n = 173) completed 3 assessments at 2-year intervals across puberty (ages 9-18 years). At baseline, we assessed objective ELS and stress sensitivity using the Traumatic Events Screening Inventory for Children. At all time points, we assessed NAcc activation using the Monetary Incentive Delay task and externalizing, internalizing, and total problems using the Youth Self-Report. We examined correlations between NAcc trajectories (extracted using linear mixed-effects models) with ELS and stress sensitivity and conducted multivariate regression analysis to examine the interaction of NAcc trajectories and biological sex in predicting symptoms of psychopathology.

RESULTS

Symptoms increased over adolescence. Stress sensitivity, but not objective ELS, was associated with decreasing trajectories of NAcc activation. Biological sex interacted with NAcc trajectories to predict psychopathology; boys, but not girls, with decreasing NAcc activation had more severe externalizing problems in adolescence. These findings were replicated in the putamen and caudate but not in the medial prefrontal cortex or control brain regions.

CONCLUSIONS

NAcc activation may be a sex-specific marker of externalizing problems in adolescence. Efforts to reduce stress sensitivity may help to decrease symptoms of psychopathology in adolescent boys.

Uncertainty as a driver of the youth mental health crisis

Mental health problems in young people have been on the rise for over a decade, with that trend accelerating during the pandemic. This review proposes that the catalyst effect of the pandemic offers insights into a key driver of increases in youth depression and anxiety: greater uncertainty. Uncertainty about many aspects of everyday life, including social connections, education, job security and health, increased during the pandemic, and this coincided with increasing rates of depression and anxiety. Lab-based developmental cognitive and clinical neuroscience research on tolerance of uncertainty and adolescent mental health shows that when adolescents fail to show age-typical tolerance of uncertainty, they are at greater risk of mental health problems. Avenues for future research to understand and promote tolerance of uncertainty in adolescents are proposed.

Neural association between cognitive function and anhedonia in adolescents with melancholic major depressive disorder: A fNIRS study

BACKGROUND

Cognitive dysfunction is common among adolescent patients with major depressive disorder (MDD). However, the pattern and magnitude of cognition impairment in patients during melancholic episodes remains unclear. The purpose of this study was to compare the neurocognitive performance and the underlying cerebral blood flow activation of adolescent patients with melancholic and non-melancholic features.

METHODS

Fifty-seven and 44 adolescent patients with MDD with or without melancholic feature (MDD-MEL/nMEL) and 58 healthy controls (HCs) were recruited. We used the repeatable battery for the assessment of neuropsychological status (RBANS) measuring neurocognitive function, and used functional near infrared spectroscopy (fNIRS) monitoring cerebral hemodynamic changes, described by β value. The non-parametric test and post-hoc analysis were conducted in RBANS scores and β values among three groups. Spearman correlation and mediating analysis was performed for RBANS scores, β values, and clinical symptoms in the MDD-MEL group.

RESULTS

There were no significant difference in RBANS scores between MDD-MEL and MDD-nMEL group. Compared with patients in MDD-nMEL, patients in MDD-MEL have lower β values in eight channels (ch10, ch16, ch20, ch25, ch27, ch37, ch41, ch45). The cognitive function is significantly correlated with anhedonia, and the β values play a partial mediating role between anhedonia and cognitive function.

LIMITATION

It's a cross-sectional study and monitoring longitudinal effects are needed to further elucidate the mechanism.

CONCLUSION

The cognitive function in adolescents with MDD-MEL may not significantly differ from those with MDD-nMEL. However, the anhedonia may influenced the cognitive function by altering the function of medial frontal cortex.

Stress to inflammation and anhedonia: Mechanistic insights from preclinical and clinical models

Anhedonia, as evidenced by impaired pleasurable response to reward, reduced reward motivation, and/or deficits in reward-related learning, is a common feature of depression. Such deficits in reward processing are also an important clinical target as a risk factor for depression onset. Unfortunately, reward-related deficits remain difficult to treat. To address this gap and inform the development of effective prevention and treatment strategies, it is critical to understand the mechanisms that drive impairments in reward function. Stress-induced inflammation is a plausible mechanism of reward deficits. The purpose of this paper is to review evidence for two components of this psychobiological pathway: 1) the effects of stress on reward function; and 2) the effects of inflammation on reward function. Within these two areas, we draw upon preclinical and clinical models, distinguish between acute and chronic effects of stress and inflammation, and address specific domains of reward dysregulation. By addressing these contextual factors, the review reveals a nuanced literature which might be targeted for additional scientific inquiry to inform the development of precise interventions.

Automatic Positive and Negative Emotion Regulation in Adolescents with Major Depressive Disorder

INTRODUCTION

Adolescents with major depressive disorder (MDD) exhibit hypoactivity to positive stimuli and hyperactivity to negative stimuli in terms of neural responses. Automatic emotion regulation (AER) activates triple networks (i.e., the central control network, default mode network, and salience network). Based on previous studies, we hypothesized that adolescents with MDD exhibit dissociable spatiotemporal deficits during positive and negative AER.

METHODS

We first collected EEG data from 32 adolescents with MDD and 35 healthy adolescents while they performed an implicit emotional Go/NoGo task. Then, we characterized the spatiotemporal dynamics of cortical activity during AER.

RESULTS

In Go trials, MDD adolescents exhibited reduced N2 amplitudes, enhanced theta power for positive pictures, and stronger bottom-up information flow from the left orbitofrontal cortex (OFC) to the right superior frontal gyrus compared to top-down information flow than the controls. In contrast, in NoGo trials, MDD adolescents exhibited elevated P3 amplitudes, enhanced theta power, and stronger top-down information flows from the right middle frontal gyrus to the right OFC and the left insula than the controls.

CONCLUSION

Overall, adolescents with MDD exhibited impaired automatic attention to positive emotions and impaired automatic response inhibition. These findings have potential implications for the clinical treatment of adolescents with MDD.

Longitudinal Associations Between Reward Responsiveness and Depression Across Adolescence

OBJECTIVE

Lower neural response to reward predicts subsequent depression during adolescence. Both pubertal development and biological sex have important effects on reward system development and depression during this period. However, relations among these variables across the transition from childhood to adolescence are not well characterized.

METHOD

Depressive symptoms, pubertal status, and the reward positivity (RewP) event-related potential component, a neural indicator of reward responsivity, were assessed in 609 community-recruited youth at 9, 12, and 15 years of age. Structural equation modeling was used to examine concurrent and prospective relations within and between depression and reward responsiveness as well as the influence of pubertal status and biological sex on these variables across assessments.

RESULTS

Stability paths for depression, the RewP, and pubertal status were significant across assessments. Compared with male participants, female participants reported more advanced pubertal status at all assessments, a smaller RewP at age 9, and higher levels of depression at age 15. More advanced pubertal status was associated with a larger RewP at age 15. Most importantly, there were bidirectional prospective effects between the RewP and depression from ages 12 to 15; a lower RewP at age 12 predicted increases in depression at age 15, whereas increased depression at age 12 predicted a lower RewP at age 15.

CONCLUSION

These findings indicate that there are bidirectional prospective effects between reward responsiveness and depression that emerge between ages 12 and 15. This may be a crucial time for studying bidirectional reward responsiveness-depression associations across time.

Neural activation to peer acceptance and rejection in relation to concurrent and prospective depression risk in adolescent and pre-adolescent girls

Neurobiological sensitivity to peer interactions is a proposed marker of risk for adolescent depression. We investigated neural response to peer rejection and acceptance in relation to concurrent and prospective depression risk in adolescent and pre-adolescent girls. Participants were 76 girls (Mage=13, 45% racial/ethnic minorities) varying in depression risk: 22 with current major depressive disorder (MDD), 30 at High Risk for MDD based on parental history, and 24 at Low Risk with no psychiatric history. Girls participated in the Chatroom-Interact task-involving rejection and acceptance feedback from fictitious peers-while undergoing functional magnetic resonance neuroimaging. Activation in response to peer rejection and acceptance was extracted from regions of interest. Depressive symptoms were assessed at 6- and 12-month follow-up. Girls with MDD showed blunted left subgenual anterior cingulate response to acceptance versus girls in High and Low Risk groups. Girls in the High Risk group showed greater right temporo-parietal junction (rTPJ) and right anterior insula (AI) activation to both acceptance and rejection versus girls in the MDD (rTPJ) and Low Risk (rTPJ, AI) groups. Greater rTPJ response to rejection was associated with fewer depressive symptoms at 12-months and mediated the association between High Risk group status and 12-month depressive symptoms; greater rTPJ response to acceptance mediated the association between High Risk and increased 12-month depressive symptoms. Our finding of associations between altered neural response to peer interactions and concurrent and prospective depression risk/resilience highlights the importance of neural underpinnings of social cognition as risk and compensatory adaptations along the pathway to depression.

Sex differences in externalizing and internalizing traits and ventral striatal responses to monetary loss

Ventral striatum (VS) processes rewarding and punishing stimuli. Women and men vary in externalizing and internalizing traits, which may influence neural responses to reward and punishment. To investigate sex differences in how individual traits influence VS responses to reward and punishment, we curated the data of the Human Connectome Project and identified 981 (473 men) subjects evaluated by the Achenbach Adult Self-Report Syndrome Scales. We processed the imaging data with published routines and extracted VS response (β) to win and to loss vs. baseline in a gambling task for correlation with externalizing and internalizing symptom severity. Men vs. women showed more severe externalizing symptoms and higher VS response to monetary losses (VS-loss β) but not to wins. Men but not women showed a significant, positive correlation between VS-loss β and externalizing traits, and the sex difference was confirmed by a slope test. The correlations of VS-loss vs. externalizing and of VS-win vs. externalizing and those of VS-loss vs. externalizing and of VS-loss vs. internalizing traits both differed significantly in slope, confirming its specificity, in men. Further, the sex-specific relationship between VS-loss β and externalizing trait did not extend to activities during exposure to negative emotion in the face matching task. To conclude, VS responses to loss but not to win and their correlation with externalizing rather than internalizing symptom severity showed sex differences in young adults. The findings highlight the relationship of externalizing traits and VS response to monetary loss and may have implications for psychological models of externalizing behaviors in men.

Splitting the reward: Differences in inflammatory marker associations with neural connectivity between reward anticipation and reward outcome in adolescents at high risk for depression

BACKGROUND

Adolescent depression is associated with both dysfunction in neural reward processing and peripheral inflammatory markers (PIMs), such as interleukin-6 (IL-6), C-reactive-protein (CRP), and tumor-necrosis factor alpha (TNFα). Few adolescent studies have examined neural-inflammatory marker associations and associated behavioral correlates, which would contribute to a better understanding of developmental processes linked to depression.

METHODS

36 adolescents at high risk of depression completed an fMRI reward task (during anticipation and outcome), blood draw for PIMs (IL-6, CRP, and TNFα), and a behavioral task assessing motivation to expend effort. Analyses examined associations of task-dependent functional connectivity (FC; ventral striatum to frontal and default mode network brain regions), and if the interaction of PIMs and task-dependent FC predicted motivation to expend effort.

RESULTS

For anticipation contrast, TNFα was associated with increased task-dependent FC between the LVS and PCC/vmPFC. In moderation analyses, for anticipation contrasts, the combination of higher IL-6 and stronger FC (LVS-precuneus/PCC) was associated with lower motivation to expend effort, while for outcome contrasts, the combination of higher IL-6 and stronger FC (VS-precuneus/PCC) was associated with greater motivation to expend effort.

CONCLUSIONS

Our findings in adolescents during an important developmental time period suggest that PIMs are directly linked to greater FC between the VS and DMN brain regions during win anticipation, consistent with prior studies. Effects of PIMs on motivation to expend effort may vary the strength/type of neural reward processing (anticipation or outcome), which could guide better understanding how inflammatory markers and neural reward substrates contribute to development of depression in high-risk adolescents.

Reward processing in adolescents with social phobia and depression

OBJECTIVE

Impaired reward processing has been found in individuals with anxiety, but also major depressive disorder (MDD). Here, we studied neural correlates of reward anticipation and processing in a sample of youth with severe social phobia and comorbid depression (SP/MDD) and investigated the specific contribution of SP and MDD symptoms.

METHODS

15 affected, unmedicated and 25 typically developing (TD) youth completed a monetary gambling task, which included a positive, negative and ambiguous reward condition. Event-related potentials representing cue processing (cue P300), reward anticipation (stimulus preceding negativity, SPN), reward sensitivity (feedback related negativity, FRN) and reward processing (reward P300) were analysed.

RESULTS

Reduced amplitudes of the right hemispheric (r)SPN and reward P300 were observed in SP/MDD compared to TD. Within the SP/MDD group SP symptoms correlated with larger rSPN, and FRN amplitudes. MDD symptoms correlated with smaller rSPN and smaller FRN positive-negative difference wave.

CONCLUSIONS

Reward anticipation and feedback processing are reduced in SP/MDD. Higher SP symptoms are associated with stronger neural activation during reward anticipation and reward sensitivity. Depressive symptoms are associated with decreased reward anticipation and sensitivity. Findings are in line with the theory of heightened vigilance in anxiety and blunted reward processing due to anhedonia in MDD.

SIGNIFICANCE

The study results can inform behavioural interventions for SP and MDD.

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.

Gray matter alterations in adolescent major depressive disorder and adolescent bipolar disorder

BACKGROUND

Gray matter volume (GMV) alterations in several emotion-related brain areas are implicated in mood disorders, but findings have been inconsistent in adolescents with major depressive disorder (MDD) or bipolar disorder (BD).

METHODS

We conducted a comprehensive meta-analysis of 35 region-of-interest (ROI) and 18 whole-brain voxel-based morphometry (VBM) MRI studies in adolescent MDD and adolescent BD, and indirectly compared the results in the two groups. The effects of age, sex, and other demographic and clinical scale scores were explored using meta-regression analysis.

RESULTS

In the ROI meta-analysis, right putamen volume was decreased in adolescents with MDD, while bilateral amygdala volume was decreased in adolescents with BD compared to healthy controls (HC). In the whole-brain VBM meta-analysis, GMV was increased in right middle frontal gyrus and decreased in left caudate in adolescents with MDD compared to HC, while in adolescents with BD, GMV was increased in left superior frontal gyrus and decreased in limbic regions compared with HC. MDD vs BD comparison revealed volume alteration in the prefrontal-limbic system.

LIMITATION

Different clinical features limit the comparability of the samples, and small sample size and insufficient clinical details precluded subgroup analysis or meta-regression analyses of these variables.

CONCLUSIONS

Distinct patterns of GMV alterations in adolescent MDD and adolescent BD could help to differentiate these two populations and provide potential diagnostic biomarkers.

Sensitive caregiving and reward responsivity: A novel mechanism linking parenting and executive functions development in early childhood

Sensitive caregiving is an essential aspect of positive parenting that influences executive functions development, but the mechanisms underlying this association are less clear. Using data from the Family Life Project, a large prospective longitudinal sample of 1292 families residing in rural, predominately low-income communities, the current study examined whether sensitive caregiving impacts executive functions development by shaping behavioral reward processing systems in early postnatal life. Results indicated that higher levels of sensitive caregiving during infancy were associated with heightened reward responsivity at age 4, which in turn predicted superior executive functions ability at age 5. Notably, children's reward responsivity partially mediated the relationship between sensitive caregiving in infancy and executive functions ability at school entry. These findings add to prior work on early experience and children's executive functions and highlight caregiver scaffolding of developing reward processing systems as a potential foundational mechanism for supporting adaptive behavior and self-regulation across the lifespan.

Word usage in spontaneous speech as a predictor of depressive symptoms among youth at high risk for mood disorders

BACKGROUND

We examined whether digital phenotyping of spontaneous speech, such as the use of specific word categories during speech samples, was associated with depressive symptoms in youth who were at familial and clinical risk for mood disorders.

METHODS

Participants (ages 13-19) had active mood symptoms, mood instability, and at least one parent with bipolar or major depressive disorder. During a randomized trial of family-focused therapy, participants were instructed to make weekly calls to a central voice server and leave speech samples in response to automated prompts. We coded youths' speech samples with the Linguistic Inquiry and Word Count system and used machine learning to identify the combination of speech features that were most closely associated with the course of depressive symptoms over 18 weeks.

RESULTS

A total of 253 speech samples were collected from 44 adolescents (mean age = 15.8 years; SD = 1.6) over 18 weeks. Speech containing affective processes, social processes, drives toward risk or reward, nonfluencies, and time orientation words were correlated with depressive symptoms at concurrent time periods (ps < 0.01). Machine learning analyses revealed that affective processes, nonfluencies, drives and risk words combined to most strongly predict changes in depressive symptoms over 18 weeks of treatment.

LIMITATIONS

Study results were limited by the small sample and the exclusion of paralinguistic or contextual variables in analyzing speech samples.

CONCLUSIONS

In youth at high risk for mood disorders, knowledge of speech patterns may inform prognoses during outpatient psychosocial treatment.

Reward enhances resilience to chronic social defeat stress in mice: Neural ECs and mGluR5 mechanism via neuroprotection in VTA and DRN

INTRODUCTION

Stress often leads to emotional disorders such as depression. The reward might render this effect through the enhancement of stress resilience. However, the effect of reward on stress resilience under different intensities of stress needs more evidence, and its potential neural mechanism has been poorly revealed. It has been reported that the endogenous cannabinoid system (ECs) and downstream metabolic glutamate receptor 5 (mGluR5) are closely related to stress and reward, which might be the potential cerebral mechanism between reward and stress resilience, but there is a lack of direct evidence. This study aims to observe the effect of reward on stress resilience under different intensities of stress and further explore potential cerebral mechanisms underlying this effect.

METHODS

Using the chronic social defeat stress model, we applied reward (accompanied by a female mouse) under different intensities of stress in mice during the modeling process. The impact of reward on stress resilience and the potential cerebral mechanism were observed after modeling through behavioral tests and biomolecules.

RESULTS

The results showed that stronger stress led to higher degrees of depression-like behavior. Reward reduced depression-like behavior and enhanced stress resilience (all p-value <0.05) (more social interaction in the social test, less immobility time in the forced swimming test, etc.), with a stronger effect under the large stress. Furthermore, the mRNA expression levels of CB1 and mGluR5, the protein expression level of mGluR5, and the expression level of 2-AG (2-arachidonoylglycerol) in both ventral tegmental area (VTA) and dorsal raphe nucleus (DRN) were significantly upregulated by reward after modeling (all p-value <0.05). However, the protein expression of CB1 in VTA and DRN and the expression of AEA (anandamide) in VTA did not differ significantly between groups. Intraperitoneal injection of a CB1 agonist (URB-597) during social defeat stress significantly reduced depression-like behavior compared with a CB1 inhibitor (AM251) (all p-value <0.05). Interestingly, in DRN, the expression of AEA in the stress group was lower than that of the control group, with or without reward (all p-value <0.05).

DISCUSSION

These findings demonstrate that combined social and sexual reward has a positive effect on stress resilience during chronic social defeat stress, potentially by influencing the ECs and mGluR5 in VTA and DRN.

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.

Striatal Activity to Reward Anticipation as a Moderator of the Association Between Early Behavioral Inhibition and Changes in Anxiety and Depressive Symptoms From Adolescence to Adulthood

Importance

The early childhood temperament of behavioral inhibition (BI), characterized by inhibited and fearful behaviors, has been associated with heightened risk for anxiety and depression across the lifespan. Although several neurocognitive correlates underlying vulnerability to the development of anxiety among inhibited children have been identified, little is known about the neurocognitive correlates underlying vulnerability to the development of depression.

Objective

To examine whether blunted striatal activation to reward anticipation, a well-documented neurocognitive vulnerability marker of depression, moderates the association between early BI and the developmental changes in depression and anxiety from adolescence to adulthood.

Design, Setting, and Participants

Participants in this prospective longitudinal study were recruited at age 4 months between 1989 and 1993 in the US. Follow-up assessments extended into 2018 (age 26 years). Data were analyzed between September 2021 to March 2022.

Main Outcomes and Measures

BI was measured through an observation paradigm in infancy (ages 14 and 24 months). Neural activity to anticipated rewards during a monetary incentive delay task was measured using functional magnetic resonance imaging in adolescence (between ages 15-18 years; 83 individuals had usable data). Anxiety and depressive symptoms were self-reported across adolescence to young adulthood (ages 15 and 26 years; n = 108). A latent change score model, accounting for the interdependence between anxiety and depression, tested the moderating role of striatal activity to reward anticipation in the association between early BI and changes in anxiety and depressive symptoms. A region of interest approach limited statistical tests to regions within the striatum (ie, nucleus accumbens, caudate head, caudate body, putamen).

Results

Of 165 participants, 84 (50.1%) were female and 162 (98%) were White. Preliminary analyses revealed significant increases in anxiety and depressive symptoms across ages 15 to 26 years, as well as individual variation in the magnitude of changes. Main analyses showed that reduced activity in the nucleus accumbens to reward anticipation moderated the association between early BI and increases in depressive (β = -0.32; b = -4.23; 95% CI, -7.70 to -0.76; P = .02), and more depressive symptoms at age 26 years (β = -0.47; b = -5.09; 95% CI, -7.74 to -2.43; P < .001). However, there were no significant interactions associated with latent changes in anxiety across age nor anxiety at age 26 years. Activity in the caudate and putamen did not moderate these associations.

Conclusions and Relevance

Blunted reward sensitivity in the ventral striatum may be a developmental risk factor connecting an inhibited childhood temperament and depression over the transition to adulthood. Future studies should examine the efficacy of prevention programs, which target maladaptive reward processing and motivational deficits among anxious youths, in reducing risks for later depression.

Multi-level predictors of depression symptoms in the Adolescent Brain Cognitive Development (ABCD) study

BACKGROUND

While identifying risk factors for adolescent depression is critical for early prevention and intervention, most studies have sought to understand the role of isolated factors rather than across a broad set of factors. Here, we sought to examine multi-level factors that maximize the prediction of depression symptoms in US children participating in the Adolescent Brain and Cognitive Development (ABCD) study.

METHODS

A total of 7,995 participants from ABCD (version 3.0 release) provided complete data at baseline and 1-year follow-up data. Depression symptoms were measured with the Child Behavior Checklist. Predictive features included child demographic, environmental, and structural and resting-state fMRI variables, parental depression history and demographic characteristics. We used linear (elastic net regression, EN) and non-linear (gradient-boosted trees, GBT) predictive models to identify which set of features maximized prediction of depression symptoms at baseline and, separately, at 1-year follow-up.

RESULTS

Both linear and non-linear models achieved comparable results for predicting baseline (EN: MAE = 3.757; R2  = 0.156; GBT: MAE = 3.761; R2  = 0.147) and 1-year follow-up (EN: MAE = 4.255; R2  = 0.103; GBT: MAE = 4.262; R2  = 0.089) depression. Parental history of depression, greater family conflict, and shorter child sleep duration were among the top predictors of concurrent and future child depression symptoms across both models. Although resting-state fMRI features were relatively weaker predictors, functional connectivity of the caudate was consistently the strongest neural feature associated with depression symptoms at both timepoints.

CONCLUSIONS

Consistent with prior research, parental mental health, family environment, and child sleep quality are important risk factors for youth depression. Functional connectivity of the caudate is a relatively weaker predictor of depression symptoms but may represent a biomarker for depression risk.

Reward sensitivity and internalizing symptoms during the transition to puberty: An examination of 9-and 10-year-olds in the ABCD Study

Early pubertal timing has been linked to increased risk for internalizing psychopathology in adolescents. Work in older adolescents and adults suggests that heightened reward sensitivity may buffer risk for internalizing symptoms. However, few studies have investigated these associations during the early transition to puberty, a window of vulnerability to mental health risk. In this preregistered study, we investigated the associations among pubertal timing, internalizing symptoms, and reward sensitivity in a large, population-based sample of 11,224 9-10 year-olds from the ABCD Study®. Using split-half analysis, we tested for within-sample replications of hypothesized effects across two age- and sex-matched subsets of the sample. Early pubertal timing was associated with higher internalizing symptoms in female and male participants across samples, with 9-10 year-olds in the mid-pubertal stage at the highest risk for internalizing symptoms. Additionally, early pubertal timing was robustly associated with greater self-reported reward sensitivity in both female and male participants. We observed inconsistent evidence for a moderating role of reward sensitivity across measurement domains (self-report, behavioral, and fMRI data), several of which differed by sex, but none of these interactions replicated across samples. Together, these findings provide unique insights into early indicators of risk for internalizing psychopathology during the transition to puberty in a large, population-based, demographically diverse sample of youth.

Family History of Depression and Neural Reward Sensitivity: Findings From the Adolescent Brain Cognitive Development Study

BACKGROUND

Previous studies have found that offspring of depressed parents exhibit reduced striatal reward response to anticipating and receiving rewards, suggesting that this may constitute a neurobiological risk marker for depression. The present study aimed to assess whether maternal and paternal depression history have independent effects on offspring reward processing and whether greater family history density of depression is associated with increased blunting of striatal reward responses.

METHODS

Data from the baseline visit of the ABCD (Adolescent Brain Cognitive Development) Study were used. After exclusion criteria, 7233 9- and 10-year-old children (49% female) were included in analyses. Neural responses to reward anticipation and receipt in the monetary incentive delay task were examined in 6 striatal regions of interest. Using mixed-effects models, we evaluated the effect of maternal or paternal depression history on striatal reward response. We also evaluated the effect of family history density on reward response.

RESULTS

Across all 6 striatal regions of interest, neither maternal nor paternal depression significantly predicted blunted response to reward anticipation or feedback. Contrary to hypotheses, paternal depression history was associated with increased response in the left caudate during anticipation, and maternal depression history was associated with increased response in the left putamen during feedback. Family history density was not associated with striatal reward response.

CONCLUSIONS

Our findings suggest that family history of depression is not strongly associated with blunted striatal reward response in 9- and 10-year-old children. Factors contributing to heterogeneity across studies need to be examined in future research to reconcile these results with past findings.

The thrill of victory: Savoring positive affect, psychophysiological reward processing, and symptoms of depression

Depression is characterized by a pattern of maladaptive emotion regulation. Recently, researchers have begun to focus on associations between depression and two positive affect regulation strategies: savoring and dampening. Savoring, or upregulation of positive affect, is positively associated with well-being and negatively associated with depression, whereas dampening, or downregulation of positive affect, is positively associated with depression, anhedonia, and negative affect. To date, no research has examined whether savoring or dampening can affect neurophysiological reactivity to reward, which previous research has shown is associated with symptoms of depression. Here, we examined associations between psychophysiological reward processing-primarily captured by the Reward Positivity (RewP), an event-related potential (ERP) deflection elicited by feedback indicating reward (vs. nonreward)-positive affect regulation strategies, and symptoms of depression. One hundred undergraduates completed questionnaires assessing affect, emotion regulation, and depressive symptoms and completed a computerized guessing task, once before and again after being randomly assigned to emotion-regulation strategy conditions. Results indicate that (a) the relationship between RewP amplitude and depressive symptoms may, in part, depend upon positive affect regulation strategies and (b) the RewP elicited by reward appears sensitive to a savoring intervention. These findings suggest that mitigating depressive symptoms in emerging adults may depend on both top-down (i.e., savoring) and bottom-up (i.e., RewP) forms of positive affect regulation and have important implications for clinical prevention and intervention efforts for depressive symptoms and disorder. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Intrinsic Connectivity and Family Dynamics: Striatolimbic Markers of Risk and Resilience in Youth at Familial Risk for Mood Disorders

BACKGROUND

Few studies to date have characterized functional connectivity (FC) within emotion and reward networks in relation to family dynamics in youth at high familial risk for bipolar disorder (HR-BD) and major depressive disorder (HR-MDD) relative to low-risk youth (LR). Such characterization may advance our understanding of the neural underpinnings of mood disorders and lead to more effective interventions.

METHODS

A total of 139 youth (43 HR-BD, 46 HR-MDD, and 50 LR) aged 12.9 ± 2.7 years were longitudinally followed for 4.5 ± 2.4 years. We characterized differences in striatolimbic FC that distinguished between HR-BD, HR-MDD, and LR and between resilience and conversion to psychopathology. We then examined whether risk status moderated FC-family dynamic associations. Finally, we examined whether baseline between-group FC differences predicted resilence versus conversion to psychopathology.

RESULTS

HR-BD had greater amygdala-middle frontal gyrus and dorsal striatum-middle frontal gyrus FC relative to HR-MDD and LR, and HR-MDD had lower amygdala-fusiform gyrus and dorsal striatum-precentral gyrus FC relative to HR-BD and LR (voxel-level p < .001, cluster-level false discovery rate-corrected p < .05). Resilient youth had greater amygdala-orbitofrontal cortex and ventral striatum-dorsal anterior cingulate cortex FC relative to youth with conversion to psychopathology (voxel-level p < .001, cluster-level false discovery rate-corrected p < .05). Greater family rigidity was inversely associated with amygdala-fusiform gyrus FC across all groups (false discovery rate-corrected p = .017), with a moderating effect of bipolar risk status (HR-BD vs. HR-MDD p < .001; HR-BD vs. LR p = .005). Baseline FC differences did not predict resilence versus conversion to psychopathology.

CONCLUSIONS

Findings represent neural signatures of risk and resilience in emotion and reward processing networks in youth at familial risk for mood disorders that may be targets for novel interventions tailored to the family context.

Age differences in neural response to reward and loss in children

The goal of this study was to examine age-related differences in children's reward processing. Focusing on reward outcome processing, we used event-related potentials to examine substages of neural response to gain versus loss feedback in a sample of 7-11-year-old children (M = 9.67, SD = 1.40) recruited from the community (N = 234; 47.6% girls, 66.2% non-Hispanic European American). Using principal components analysis (PCA), we focused on temporospatial combinations that closely resembled the RewP, fb-P3, and fb-LPP in temporal and spatial distributions. Two of these, the PCA factors reflecting the RewP and fb-LPP, demonstrated age-related differences in response to gains versus losses. Age-related changes in the RewP were specific to gain feedback, with RewP amplitudes to gain, but not loss, increasing from middle to late childhood. In contrast, age-related changes in fb-LPP were specific to loss feedback, with fb-LPP amplitudes to losses, but not gains, decreasing from middle to late childhood. Follow-up analyses revealed that children younger than age 8 exhibited larger fb-LPP responses to loss than gain, whereas children older than age 10 exhibited larger RewP responses to gain than loss. Similar results were obtained using mean amplitude-based ERP indices and the results do not appear to have been due to age-related differences in the latency or location of the ERPs themselves. These results highlight the importance of examining distinct substages of reward outcome processing and suggest that robust neural responses to loss feedback may emerge earlier in childhood than responses to gains.

Neural and peripheral markers of reward during positive social evaluation are associated with less clinician-rated depression symptom severity in adolescence

Although blunted sensitivity to reward is thought to play a key role in promoting risk for depression, most research on this topic has utilized monetary reward paradigms and focused on currently depressed adults. To address this issue, we analyzed neural reward and β-endorphin data from the Psychobiology of Stress and Adolescent Depression (PSY SAD) Study, which recruited a well-characterized sample of adolescent girls at high vs. low risk for major depressive disorder (MDD) (N = 52, M_age = 14.90, SD = 1.35) based on their mothers’ lifetime history of MDD. As hypothesized, greater striatal activity while receiving positive (vs. neutral) social evaluation was associated with lower depression symptom severity as independently assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS). This association was present for girls at high but not low risk for MDD, suggesting that this neural response may represent a pre-clinical marker of risk for depression. Consistent with these results, higher post-social evaluation levels of a peripheral marker of reward sensitivity, β-endorphin, were related to lower clinician-rated depression symptom severity. Together, these results indicate that neural and peripheral markers of responsivity to social reward are both related to depression severity, which may have implications for understanding the pathophysiology of depression.

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The neurobiological reward processes underlying adolescent depression risk are unclear.

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To address this issue, we recruited adolescent girls at high vs. low risk for MDD.

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We assessed their striatal activity, β-endorphin levels, & depression symptom severity.

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Striatal activity & β-endorphin levels during social evaluation predicted depression severity.

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These effects differed for high-vs. low-risk youth, suggesting pre-clinical risk biomarkers.

Drift-Diffusion Model Reveals Impaired Reward-Based Perceptual Decision-Making Processes Associated with Depression in Late Childhood and Early Adolescent Girls

Adolescent girls are a high-risk stratum for the emergence of depression. Previous research has established that depression is associated with blunted responses to rewards. Research using Drift Diffusion Model (DDM) has found that deficits in accumulating reward-based evidence characterize adult depression. However, little is known about how reduced reward sensitivity is reflected in the computational processes involved in reward-based decision-making in late childhood and early adolescent depression.One hundred and sixty-six 8- to 14-year-old girls completed a probabilistic reward-based decision-making task. Participants were instructed to identify which one of two similar visual stimuli were presented, and correct responses were rewarded with unequal probabilities. Analysis using hierarchical DDM quantified rate of evidence accumulation (i.e., drift rate) and starting point. Depression severity was measured using the Children's Depression Inventory.Across all participants, there was a higher drift rate, indicating faster evidence accumulation, for the more frequently rewarded than the less frequently rewarded decision. In addition, the starting point of the evidence accumulation was closer to the more frequently rewarded decision, indicating a starting point bias. Higher depression severity was associated with a slower drift rate for both types of decisions. Higher depression severity was associated with a smaller starting point bias towards the more frequently rewarded decision.The current study uses computational modeling to reveal that late childhood and early adolescent girls with greater depression demonstrate impairments in the reward-related evidence accumulation process.

EEG time-frequency analysis reveals blunted tendency to approach and increased processing of unpleasant stimuli in dysphoria

To date, affective and cognitive processing of emotional information in individuals with depressive symptoms have been examined through peripheral psychophysiological measures, event-related potentials, and time–frequency analysis of oscillatory activity. However, electrocortical correlates of emotional and cognitive processing of affective content in depression have not been fully understood. Time–frequency analysis of electroencephalographic activity allows disentangling the brain's parallel processing of information. The present study employed a time–frequency approach to simultaneously examine affective disposition and cognitive processing during the viewing of emotional stimuli in dysphoria. Time–frequency event-related changes were examined during the viewing of pleasant, neutral and unpleasant pictures in 24 individuals with dysphoria and 24 controls. Affective disposition was indexed by delta and alpha power, while theta power was employed as a correlate of cognitive elaboration of the stimuli. Cluster-based statistics revealed a centro-parietal reduction in delta power for pleasant stimuli in individuals with dysphoria relative to controls. Also, dysphoria was characterized by an early fronto-central increase in theta power for unpleasant stimuli relative to neutral and pleasant ones. Comparatively, controls were characterized by a late fronto-central and occipital reduction in theta power for unpleasant stimuli relative to neutral and pleasant. The present study granted novel insights on the interrelated facets of affective elaboration in dysphoria, mainly characterized by a hypoactivation of the approach-related motivational system and a sustained facilitated cognitive processing of unpleasant stimuli.

Reward- and threat-related neural function associated with risk and presence of depression in adolescents: a study using a composite risk score in Brazil

BACKGROUND

Neuroimaging studies on adolescents at risk for depression have relied on a single risk factor and focused on adolescents in high-income countries. Using a composite risk score, this study aims to examine neural activity and connectivity associated with risk and presence of depression in adolescents in Brazil.

METHODS

Depression risk was defined with the Identifying Depression Early in Adolescence Risk Score (IDEA-RS), calculated using a prognostic model that included 11 socio-demographic risk factors. Adolescents recruited from schools in Porto Alegre were classified into a low-risk (i.e., low IDEA-RS and no lifetime depression), high-risk (i.e., high IDEA-RS and no lifetime depression), or clinically depressed group (i.e., high IDEA-RS and depression diagnosis). One hundred fifty adolescents underwent a functional MRI scan while completing a reward-related gambling and a threat-related face-matching task. We compared group differences in activity and connectivity of the ventral striatum (VS) and amygdala during the gambling and face-matching tasks, respectively, and group differences in whole-brain neural activity.

RESULTS

Although there was no group difference in reward-related VS or threat-related amygdala activity, the depressed group showed elevated VS activity to punishment relative to high-risk adolescents. The whole-brain analysis found reduced reward-related activity in the lateral prefrontal cortex of patients and high-risk adolescents compared with low-risk adolescents. Compared with low-risk adolescents, high-risk and depressed adolescents showed reduced threat-related left amygdala connectivity with thalamus, superior temporal gyrus, inferior parietal gyrus, precentral gyrus, and supplementary motor area.

CONCLUSIONS

We identified neural correlates associated with risk and presence of depression in a well-characterized sample of adolescents. These findings enhance knowledge of the neurobiological underpinnings of risk and presence of depression in Brazil. Future longitudinal studies are needed to examine whether the observed neural patterns of high-risk adolescents predict the development of depression.

Neural correlates of reward processing distinguish healthy youth at familial risk for bipolar disorder from youth at familial risk for major depressive disorder

Youth at familial risk for bipolar disorder (BD-risk) and major depressive disorder (MDD-risk) have aberrant reward processing, a core feature of these mood disorders. Whether BD risk differentiates from MDD risk in reward processing merits further study. We compared neural activation and connectivity during anticipation and outcome of monetary gain and loss during fMRI using the Monetary Incentive Delay (MID) Task among BD-risk (n = 40), MDD-risk (n = 41), and healthy comparison youth (HC) (n = 45), in the absence of any lifetime or current history of psychopathology [mean age 13.09 ± 2.58, 56.3% female]. Participants completed the MID task at baseline and were followed for behavioral and clinical outcomes over 4.37 ± 2.29 years. Region-of-interest (ROI) analyses conducted using anatomically defined thalamus, ventrolateral prefrontal cortex, nucleus accumbens, and putamen seeds showed that relative to MDD-risk and HC, BD-risk had decreased activation of the thalamus during anticipation of monetary gain [F(2,118) = 4.64, p = 0.01 (FDR-corrected p = 0.04)]. Psychophysiological interaction analyses revealed that BD-risk had less connectivity between the thalamus and left middle frontal gyrus (Z > 3.1, p < 0.001) and left-superior temporal gyrus (Z > 3.1, p < 0.05) compared with MDD-risk. Voxelwise, BD-risk had decreased activation in the cerebellum during anticipation and outcome of monetary gain relative to MDD-risk and HC (Z > 3.1, p < 0.001; Z > 3.1, p < 0.01). In BD-risk, decreased thalamic connectivity was associated with increased impulsivity at baseline and reduced prosocial behavior at follow-up. Reduced thalamic activation and connectivity during reward processing may distinguish familial risk for BD from familial risk for MDD and represent early markers of vulnerability that may herald social dysfunction later in adolescence.

Functional connectivity between the parahippocampal gyrus and the middle temporal gyrus moderates the relationship between problematic mobile phone use and depressive symptoms: Evidence from a longitudinal study

BACKGROUND AND AIM

Problematic mobile phone use (PMPU) is prevalent and increases the risk for a variety of health problems. However, few studies have explored the neural mechanisms that might render adolescents more or less vulnerable. Here, we aimed to identify whether PMPU is associated with depressive symptoms and whether this relationship is moderated by intrinsic functional connectivity (iFC) which is associated with PMPU.

METHODS

In this longitudinal study, we included 238 students (mean age = 19.05, SD = 0.81) that came from a university in Hefei, China. They all finished MRI scans at baseline and completed questionnaires both at baseline and 1 year later. A self-rating questionnaire for adolescent problematic mobile phone use and depression anxiety stress scale-21 were used to assess PMPU and depressive symptoms. We first assessed the relationship between PMPU and depressive symptoms using an autoregressive cross-lagged model. Then, we detected the brain regions that were associated with PMPU. Moreover, the neuroimaging results were extracted to explore whether the iFC of these brain regions moderated the relationship between PMPU and depression.

RESULTS

Consistent with our hypotheses, PMPU was positively associated with depressive symptoms, and the relationship between PMPU and depressive symptoms was moderated by iFC of the left parahippocampal gyrus-right middle temporal gyrus both at baseline and after 1 year (β = 0.554, P = 0.003; β = 0.463, P = 0.016, respectively).

CONCLUSIONS

These results advance the understanding of PMPU and suggest that iFC of the left parahippocampal gyrus-right middle temporal gyrus may be a neurobiological contributor to its relationship with depressive symptoms.

Psychometric properties of the Dimensional Anhedonia Rating Scale in Chinese typical, subthreshold, and clinically depressed adolescents

The Dimensional Anhedonia Rating Scale measures state anhedonia in multiple domains, such as hobbies, food and drink, social activities, and sensory experience, and it has good reliability and validity in adult samples. However, no study has examined the psychometrical properties of this scale in adolescents. The present study examined its reliability and validity in adolescents with and without depression. In Study 1, 988 high-school students completed the Dimensional Anhedonia Rating Scale; 915 completed the second-round survey 3 months later. Confirmatory factor analysis was used to determine the factor structure. Additionally, internal consistency and test-retest reliability, and concurrent, convergent, and divergent validity were assessed in typical adolescents. In Study 2, the Dimensional Anhedonia Rating Scale was administrated to 108 patients with major depressive disorder, 108 adolescents with subthreshold depression, and 108 healthy controls. Factor structure and convergent validity were assessed in the clinical and subclinical groups. Finally, a one-way analysis of variance (ANOVA) was applied to examine the effect of depression severity on the scale scores. The results of Study 1 indicated that a four-factor model (i.e., hobbies, food and drink, social activities, and sensory experience) best fit the data. Meanwhile, the scale also yielded good concurrent, convergent, and divergent validity, as well as high internal consistency and test-retest reliability, in typical adolescents. In Study 2, goodness-of-fit statistics also suggested a good fit for the four-factor model in the two depressed groups. The one-way ANOVA revealed significant group differences in the total and factor scores, whereby the major depressive disorder group had lower scores than the subthreshold depression group, whose scores were lower than the healthy controls, indicating excellent eligibility of the scale in depressed adolescents. The Chinese version of the Dimensional Anhedonia Rating Scale is a reliable and valid instrument to comprehensively measure state anhedonia in Chinese typical and depressed adolescents.

Relationships Among Sleep Disturbance, Reward System Functioning, Anhedonia, and Depressive Symptoms

Recent models propose reward system dysfunction as a key mediator of the relationship between sleep and depression and anhedonia. This study explored interrelationships among sleep disturbance, depressive symptoms, anhedonia, and reward responsiveness. Two-hundred and sixty undergraduate students completed questionnaires and a daily diary paradigm assessing sleep, reward responsiveness, depression, anhedonia, and positive affect over 1 week. Baseline sleep disturbance was associated with depressive symptoms, anhedonia, and reward responsiveness. Daily diary sleep parameters showed differential associations with anticipatory versus consummatory reward responsiveness and positive affect. Poorer sleep quality, shorter sleep duration, and longer awakening after sleep onset predicted blunted anticipatory and consummatory reward responsiveness, while increased sleep onset latency and lower sleep efficiency predicted only decreased consummatory reward responsiveness. All sleep indices, except sleep onset latency, were associated with positive affect. Findings demonstrate unique associations between disparate sleep disturbance and reward responsiveness elements, highlighting new treatment mechanisms for anhedonia and depression.

Proteomic Insights Into Susceptibility and Resistance to Chronic-Stress-Induced Depression or Anxiety in the Rat Striatum

Chronic stress is a key factor for the onset of anxiety and depression disorders. However, the stress-induced common and unique molecular basis of the two psychiatric disorders is not fully known and still needs to be explored. Previously, we employed a chronic mild stress (CMS) procedure to induce a rat model including depression-susceptible (Dep-Sus), anxiety-susceptible (Anx-Sus), and insusceptible (Insus) cohorts. In this work, we continuously analyze the striatal proteomes of the three stressed cohorts by the use of comparative proteomics and bioinformatics approaches. Through isobaric tags for relative and absolute quantitation (iTRAQ)-based analysis, 386 abnormally expressed proteins in total were identified. These deregulated proteins are involved in various biological functions and significant pathways that are potentially connected with resistance and susceptibility to CMS-caused anxious- or depressive-like behaviors and, hence, could act as suggestive protein targets. A further parallel reaction monitoring-based independent investigation shows that alterations in Pak5, Dgkg, Scn4b, Rb1cc1, and Acin1; Ggps1, Fntb, Nudt19, Ufd1, and Ndufab1; and Dnajb12, Hbb2, Ap2s1, Ip6k1, and Stk4 were specifically connected with Dep-Sus, Anx-Sus, or Insus groups, respectively, potentially indicating that identical CMS treatment results in the different changes in the striatal protein regulations. Overall, our current proteomics study of the striatum provides an important molecular foundation and comprehensive insights into common and specific deregulations correlated with pathophysiological mechanisms that underlie resistance and susceptibility to chronic stress-induced anxiety or depression.

Polygenic risk for neuroticism moderates response to gains and losses in amygdala and caudate: Evidence from a clinical cohort

BACKGROUND

Neuroticism is a heritable trait that contributes to the vulnerability to depression. We used polygenic risk scores (PRS) to examine genetic vulnerability to neuroticism and its associations with reward/punishment processing in a clinical sample with mood, anxiety, and substance use disorders. It was hypothesized that higher PRS for neuroticism is associated with attenuated neural responses to reward/punishment.

METHOD

Four hundred sixty-nine participants were genotyped and their PRSs for neuroticism were computed. Associations between PRS for neuroticism and anticipatory processing of monetary incentives were examined using functional magnetic resonance imaging.

RESULTS

Individuals with higher PRS for neuroticism showed less anticipatory activation in the left amygdala and caudate region to incentives regardless of incentive valence. Further, these individuals exhibited altered sensitivity to gain/loss processing in the right anterior insula. Higher PRSs for neuroticism were also associated with reduced processing of gains in the precuneus.

LIMITATIONS

The study population consisted of a transdiagnostic sample with dysfunctions in positive and negative valence processing. PRS for neuroticism may be correlated with current clinical symptoms due to the vulnerability to psychiatric disorders.

CONCLUSIONS

Greater genetic loading for neuroticism was associated with attenuated anticipatory responsiveness in reward/punishment processing with altered sensitivity to valences. Thus, a higher genetic risk for neuroticism may limit the degree to which positive and/or negative outcomes influence the current mood state, which may contribute to the development of positive and negative affective dysfunctions in individuals with mood, anxiety, and addictive disorders.

An informatics approach to examine decision-making impairments in the daily life of individuals with depression

Mental health informatics studies methods that collect, model, and interpret a wide variety of data to generate useful information with theoretical or clinical relevance to improve mental health and mental health care. This article presents a mental health informatics approach that is based on the decision-making theory of depression, whereby daily life data from a natural sequential decision-making task are collected and modeled using a reinforcement learning method. The model parameters are then estimated to uncover specific aspects of decision-making impairment in individuals with depression. Empirical results from a pilot study conducted to examine decision-making impairments in the daily lives of university students with depression are presented to illustrate this approach. Future research can apply and expand on this approach to investigate a variety of daily life situations and psychiatric conditions and to facilitate new informatics applications. Using this approach in mental health research may generate useful information with both theoretical and clinical relevance and high ecological validity.

Maladaptive Avoidance Learning in the Orbitofrontal Cortex in Adolescents With Major Depression

BACKGROUND

Understanding the mechanisms in the brain's incentive network that give rise to symptoms of major depressive disorder (MDD) during adolescence provides new perspectives to address MDD in early stages of development. This functional magnetic resonance imaging study determines whether instrumental vigor and brain responses to appetitive and aversive monetary incentives are altered in adolescent MDD and associated with symptom severity.

METHODS

Adolescents with moderate to severe MDD (n = 30, mean age [SD] = 16.1 [1.4] years) and healthy control subjects (n = 33, mean age = 16.2 [1.9] years) matched for age, sex, and IQ performed a monetary incentive delay task. During outcome presentation, prediction error signals were used to study the response and coupling of the incentive network during learning of cue-outcome associations. A computational reinforcement model was used to assess adaptation of response vigor. Brain responses and effective connectivity to model-derived prediction errors were assessed and related to depression severity and anhedonia levels.

RESULTS

Participants with MDD behaved according to a more simplistic learning model and exhibited slower learning. Effective connectivity analysis of functional magnetic resonance imaging data revealed that impaired loss error processing in the orbitofrontal cortex was associated with aberrant gain control. Anhedonia scores correlated with loss-related error signals in the posterior insula and habenula.

CONCLUSIONS

Adolescent MDD is selectively related to impaired processing of error signals during loss, but not reward, in the orbitofrontal cortex. Aberrant evaluation of loss outcomes might reflect an early mechanism of how negative bias and helplessness manifest in the brain. This approach sheds light on pathomechanisms in MDD and may improve early diagnosis and treatment selection.

Transdiagnostic neuroimaging of reward system phenotypes in ADHD and comorbid disorders

ADHD is a disorder characterized by changes in the reward system and which is highly comorbid with other mental disorders, suggesting common neurobiological pathways. Transdiagnostic neuroimaging findings could help to understand whether a dysregulated reward pathway might be the actual link between ADHD and its comorbidities. We here synthesize ADHD neuroimaging findings on the reward system with findings in obesity, depression, and substance use disorder including their comorbid appearance regarding neuroanatomical features (structural MRI) and activation patterns (resting-state and functional MRI). We focus on findings from monetary-incentive-delay (MID) and delay-discounting (DD) tasks and then review data on striatal connectivity and volumetry. Next, for better understanding of comorbidity in adult ADHD, we discuss these neuroimaging features in ADHD, obesity, depression and substance use disorder and ask whether ADHD heterogeneity and comorbidity are reflected by a common dysregulation in the reward system. Finally, we highlight conceptual issues related to heterogeneous paradigms, different phenotyping, longitudinal prediction and highlight some promising future directions for using striatal reward functioning as a clinical biomarker.

Ketamine Rapidly Enhances Glutamate-Evoked Dendritic Spinogenesis in Medial Prefrontal Cortex Through Dopaminergic Mechanisms

BACKGROUND

Ketamine elicits rapid onset antidepressant effects in patients with clinical depression through mechanisms hypothesized to involve the genesis of neocortical dendritic spines and synapses. Yet, the observed changes in dendritic spine morphology usually emerge well after ketamine clearance, raising questions about the link between rapid behavioral effects of ketamine and plasticity.

METHODS

Here, we used two-photon glutamate uncaging/imaging to focally induce spinogenesis in the medial prefrontal cortex, directly interrogating baseline and ketamine-associated plasticity of deep layer pyramidal neurons in C57BL/6 mice. We combined pharmacological, genetic, optogenetic, and chemogenetic manipulations to interrogate dopaminergic mechanisms underlying ketamine-induced rapid enhancement in evoked plasticity and associated behavioral changes.

RESULTS

We found that ketamine rapidly enhances glutamate-evoked spinogenesis in the medial prefrontal cortex, with timing that matches the onset of its behavioral efficacy and precedes changes in dendritic spine density. Ketamine increases evoked cortical spinogenesis through dopamine Drd1 receptor (Drd1) activation that requires dopamine release, compensating blunted plasticity in a learned helplessness paradigm. The enhancement in evoked spinogenesis after Drd1 activation or ketamine treatment depends on postsynaptic protein kinase A activity. Furthermore, ketamine's behavioral effects are blocked by chemogenetic inhibition of dopamine release and mimicked by activating presynaptic dopaminergic terminals or postsynaptic Gα_s-coupled cascades in the medial prefrontal cortex.

CONCLUSIONS

Our findings highlight dopaminergic mediation of rapid enhancement in activity-dependent dendritic spinogenesis and behavioral effects induced by ketamine.

The functional neural architecture of dysfunctional reward processing in autism

Functional imaging studies have found differential neural activation patterns during reward-paradigms in patients with autism spectrum disorder (ASD) compared to neurotypical controls. However, publications report conflicting results on the directionality and location of these aberrant activations. We here quantitatively summarized relevant fMRI papers in the field using the anatomical likelihood estimation (ALE) algorithm. Patients with ASD consistently showed hypoactivations in the striatum across studies, mainly in the right putamen and accumbens. These regions are functionally involved in the processing of rewards and are enrolled in extensive neural networks involving limbic, cortical, thalamic and mesencephalic regions. The striatal hypo-activations found in our ALE meta-analysis, which pooled over contrasts derived from the included studies on reward-processing in ASD, highlight the role of the striatum as a key neural correlate of impaired reward processing in autism. These changes were present for studies using social and non-social stimuli alike. The involvement of these regions in extensive networks associated with the processing of both positive and negative emotion alike might hint at broader impairments of emotion processing in the disorder.