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.

Associations between physical activity, sedentary time, and neurocognitive function during adolescence: Evidence from accelerometry and the flanker P300.

Physical activity and sedentary behavior are two lifestyle factors related to overall health during adolescence. Public health efforts emphasize the importance of increasing physical activity to improve physical and mental health outcomes, including neurocognitive functioning. However, the unique effects of sedentary behavior on neurocognitive functioning remain unclear. This study aimed to investigate associations between daily moderate-to-vigorous physical activity (MVPA), sedentary time, and neurocognitive functioning during adolescence. Fifty-seven participants (37% female) between the ages of 13 and 17 years wore an accelerometer on their non-dominant wrist for approximately 1 week to quantify daily MVPA and sedentary time prior to completing a flanker task to elicit P300 amplitude at a laboratory visit. Results indicated that daily MVPA and sedentary time exhibited unique, significant associations with P300 amplitude in opposing directions: increased daily MVPA was correlated with larger P300 amplitudes, while increased daily sedentary time was linked to reduced P300 amplitudes. Notably, these associations remained significant even after adjusting for age, sex, and BMI-for-age percentile. These findings underscore the independent influence of daily MVPA and sedentary time on neurocognitive functioning during adolescence. Future research should explore whether modifying MVPA levels can improve neurocognitive outcomes-including the P300-during adolescence, and determine whether reducing sedentary time results in similar or differential effects.

Examining Blunted Initial Response to Reward and Recent Suicidal Ideation in Children and Adolescents Using Event-Related Potentials: Failure to Conceptually Replicate Across Two Independent Samples.

A recent study by Tsypes and colleagues (2019) found that children with recent suicidal ideation had blunted neural reward processing, as measured by the reward positivity (RewP), compared to matched controls, and that this difference was driven by reduced neural responses to monetary loss, rather than to reward. Here, we aimed to conceptually replicate and extend these findings in two samples (n = 264, 27 with suicidal ideation; and n = 314, 49 with suicidal ideation at baseline) of children and adolescents (11 to 15 years and 8 to 15 years, respectively). Results from both samples showed no evidence that children and adolescents with suicidal ideation have abnormal reward or loss processing, nor that reward processing predicts suicidal ideation two years later. The results highlight the need for greater statistical power, as well as continued research examining the neural underpinnings of suicidal thoughts and behaviors.

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.

Corporal Punishment Is Uniquely Associated With a Greater Neural Response to Errors and Blunted Neural Response to Rewards in Adolescence.

BACKGROUND: Although corporal punishment is a common form of punishment with known negative impacts on health and behavior, how such punishment affects neurocognitive systems is relatively unknown. METHODS: To address this issue, we examined how corporal punishment affected neural measures of error and reward processing in 149 adolescent boys and girls of ages 11 to 14 years (mean age [SD] = 11.02 [1.16]). Corporal punishment experienced over the lifetime was assessed using the Stress and Adversity Inventory. In addition, participants completed a flankers task and a reward task to measure the error-related negativity and reward positivity, respectively, as well as measures of anxiety and depressive symptoms. RESULTS: As hypothesized, participants who experienced lifetime corporal punishment reported more anxiety and depressive symptoms. Experiencing corporal punishment was also related to a larger error-related negativity and blunted reward positivity. Importantly, corporal punishment was independently related to a larger error-related negativity and a more blunted reward positivity beyond the impact of harsh parenting and lifetime stressors. CONCLUSIONS: Corporal punishment appears to potentiate neural response to errors and decrease neural response to rewards, which could increase risk for anxiety and depressive symptoms.

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.

Reduced electrocortical responses to pleasant pictures in depression: A brief report on time-domain and time-frequency delta analyses.

BACKGROUND: The late positive potential (LPP) to pleasant content is an electrocortical indicator of blunted emotional reactivity in depression. A reduced time-frequency delta power has never been investigated in clinical samples. The present study examined time-frequency delta in depression and at investigated whether the combination of time-domain and time-frequency data would explain additional variance in the depression status. METHODS: The study was a secondary analysis of data collected during a passive viewing task of pleasant and neutral pictures in a community-based sample of 75 participants with a current depressive disorder and 42 controls. A time-frequency analysis on event-related changes within delta frequency band was conducted. RESULTS: Cluster-based statistics revealed a centro-parietal increase in delta power to pleasant relative to neutral pictures in the control group but not within the depression group. Moreover, a fronto-centro-parietal reduction in delta power to pleasant pictures emerged in depression relative to controls. Both a smaller LPP and delta power to pleasant pictures were related to depression status. The combination of LPP and delta power explained a greater amount of variance compared to the model where LPP was entered as the only predictor of depression status. CONCLUSIONS: These data suggest that delta power might be a promising electrocortical correlate of the hypoactivation of the approach-related motivational system in depression. Additionally, a blunted delta and LPP might reflect unique processes related to depression. A combination of these measures can be leveraged together to enhance clinical utility and to shed light on the underlying mechanisms associated with depression.

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.

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.

Suicidal thoughts, behaviors, and event-related potentials: A systematic review and meta-analysis.

Suicidal thoughts and behaviors (STBs) are thought to result from, at least in part, abnormalities in various neural systems. Event-related potentials (ERPs) are a useful method for studying neural activity and can be leveraged to study neural deficits related to STBs; however, it is unknown how effective ERPs are at differentiating various STB groups. The present meta-analysis examined how well ERPs can differentiate (a) those with and without suicidal ideation, (b) those with and without suicide attempts, (c) those with different levels of suicide risk, and (d) differences between those with suicide attempts versus those with suicidal ideation only. This meta-analysis included 208 effect sizes from 2,517 participants from 27 studies. We used a random-effects meta-analysis using a restricted maximum likelihood estimator with robust variance estimation. We meta-analyzed ERP-STB combinations that had at least three effect sizes across two or more studies. A qualitative review found that for each ERP and STB combination, the literature is highly mixed. Our meta-analyses largely did not find significant relationships between STBs and ERPs. We also found that the literature is likely severely underpowered, with most studies only being sufficiently powered to detect unrealistically large effect sizes. Our results provided little-to-no support for a reliable relationship between the ERPs assessed and STBs. However, the current literature is severely underpowered, and there are many methodological weaknesses that must be resolved before making this determination. We recommend large-scale collaboration and improvements in measurement practices to combat the issues in this literature.

Doors P300 moderates the relationship between reward positivity and current depression status in adults.

BACKGROUND: Previous research has found deficits in both the reward positivity (RewP) and P300 components of the event-related potential (ERP) in relation to depression. The current study examined whether the P300, elicited from imperative stimuli in a gambling task, relates to depression - and can be utilized in tandem with the RewP to better account for individual differences in depression. METHODS: In the current study, 80 adults with current depression (Mage = 39.65, 79% female) and 43 healthy controls (Mage = 37.02, 81% female) completed clinical interviews, self-report questionnaires, and the doors gambling task while EEG was recorded. RESULTS: Results indicated a reduced P300 to doors stimuli (i.e., doors P300) in depression, especially among depressed individuals reporting heightened anhedonia. Gain and loss feedback P300s did not differ between groups. Moreover, the doors P300 moderated the association between RewP and depression status: individuals with relatively intact reward processing (i.e., larger RewP) were more likely to be currently depressed if they exhibited a reduced P300. LIMITATIONS: The majority of the sample identified as Caucasian which reduces generalizability of current results. Additionally, the current study is cross sectional design which limits insight into how these ERPs coincide with changes in the disorder. CONCLUSIONS: The current study demonstrates that a novel P300 component to the doors stimulus appears to be blunted in currently depressed individuals, and that using the doors P300 in combination with the RewP accounts for significantly more variance in depression.

The impact of a single session of aerobic exercise on positive emotional reactivity in depression: Insight into individual differences from the late positive potential.

Depression has been characterized by a broad disengagement from the environment, as reflected by dampened positive and negative emotional reactivity. Research has shown that acute exercise may enhance positive emotional reactivity in healthy adults. It is unknown whether it can alter positive emotional reactivity in depression. In the present study, positive emotional reactivity was assessed using the late positive potential (LPP) event-related potential before and after 30 min of moderate-intensity aerobic exercise in 43 adults with current or a lifetime history of depression (Mage = 32.74 years; Min/Max = 18/59) and 18 never-depressed healthy adults (Mage = 37.94 years; Min/Max = 21/61). Acute exercise increased the LPP for healthy adults; the LPP did not change among those with current or a lifetime history of depression. A secondary aim was to identify moderators of change in positive emotional reactivity among subgroups of adults with current depression. Compared to adults with impaired mood reactivity, those with intact mood reactivity had a pre-to-post increase in the LPP. The current study provides preliminary support for the LPP as a neural indicator of exercise efficacy and highlights individual differences in response to acute exercise in depression.

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.

Reduced neural response to reward and pleasant pictures independently relate to depression.

BACKGROUND: Multiple studies have found a reduced reward positivity (RewP) among individuals with major depressive disorder (MDD). Event-related potential studies have also reported blunted neural responses to pleasant pictures in MDD as reflected by the late positive potential (LPP). These deficits have been interpreted broadly in terms of anhedonia and decreased emotional engagement characteristic of depression. METHODS: In the current study, a community-based sample of 83 participants with current MDD and 45 healthy individuals performed both a guessing task and a picture viewing paradigm with neutral and pleasant pictures to assess the RewP and the LPP, respectively. RESULTS: We found that both RewP and LPP to pleasant pictures were reduced in the MDD group; moreover, RewP and LPP were both independent predictors of MDD status. Within the MDD group, a smaller RewP predicted impaired mood reactivity in younger but not older participants. Smaller LPP amplitudes were associated with increased anhedonia severity in the MDD group. CONCLUSIONS: These data replicate and merge separate previous lines of research, and suggest that a blunted RewP and LPP reflect independent neural deficits in MDD - which could be used in conjunction to improve the classification of depression.

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

Blunted reward processing both characterizes major depressive disorder and predicts increases in depressive symptoms. However, little is known about the interaction between blunted reward processing and other risk factors in relation to increases in depressive symptoms. Stressful life events and sleep problems are prominent risk factors that contribute to the etiopathogenesis of depression and have been linked to reward dysfunction; these factors may interact with reward dysfunction to predict increased depressive symptoms. In a large sample of 8- to 14-year-old adolescent girls, the current study examined how blunted reward processing, stressful life events, and sleep problems at baseline interacted to predict increases in depressive symptoms 1 year later. Reward processing was indexed by the reward positivity (RewP), an event-related potential elicited during a simple monetary reward paradigm (i.e., Doors task). Two-way interactions confirmed that a blunted RewP predicted increased depressive symptoms at (a) high levels of stress but not average or low levels of stress, and (b) high and average levels of sleep problems but not low levels of sleep problems. Finally, a 3-way interaction confirmed that a blunted RewP predicted increased depressive symptoms at high levels of stress and sleep problems but not average or low levels of stress and sleep problems. Thus, adolescents characterized by low reward response (i.e., blunted RewP) were at an increased risk of developing depressive symptoms if they experienced increased stressful life events or sleep problems; moreover, risk was greatest among adolescents characterized by all 3.

Aberrant attentional bias to sad faces in depression and the role of stressful life events: Evidence from an eye-tracking paradigm.

Attentional biases are thought to be involved in the etiopathogenesis of depressive disorders. Recent studies indicate eye-tracking techniques could overcome methodological issues of traditional reaction time bias measures and be used to reliably quantify biases in attention. In the current study, 50 participants with a current depressive disorder and 31 never-depressed individuals performed a free-viewing eye-tracking paradigm with two counterbalanced blocks; one contained four-by-four arrays of happy and neutral faces, the other arrays of sad and neutral faces. Average dwell-times were analyzed, and internal consistency was examined. Dwell-time measures had good to excellent internal consistency. Both groups were characterized by increased dwell-time to happy compared to neutral faces (i.e., bias toward positive faces). Never-depressed participants showed a bias away from sad stimuli (i.e., increased dwell-time to neutral compared to sad faces), that was not evident in the depressed group. Moreover, depressed individuals dwelled longer on sad stimuli than never-depressed participants. Within depressed participants, bias to sad faces was associated with both childhood trauma and recent negative life events. Results demonstrate that an attentional bias towards sad faces in depression can be reliably assessed using free-viewing eye-tracking technique and its magnitude is exacerbated by the experience of stressful life events.

Gender differences in anxiety: The mediating role of sensitivity to unpredictable threat.

Anxiety disorders and symptoms disproportionately impact women relative to men, but it is unclear what mechanism(s) contribute to this phenomenon. The present study examined sensitivity to unpredictable threat as a potential mechanism of gender differences in panic symptoms. The sample included 67 participants (35 women) who completed the no, predictable, and unpredictable threat (NPU-threat) startle paradigm with electric shocks as the aversive stimulus. Participants also completed the self-report Inventory of Depression and Anxiety Symptoms to assess current panic and depression symptoms. Results indicated that women, relative to men, reported greater panic symptoms and demonstrated increased startle potentiation in anticipation of predictable and unpredictable threat. Furthermore, across all participants increased startle potentiation in anticipation of unpredictable (but not predictable) threat was associated with greater panic symptoms, but there was no relationship with depression symptoms. Finally, the gender difference in panic symptoms was mediated by startle potentiation in anticipation of unpredictable (but not predictable) threat. The present study suggests that a heightened sensitivity to unpredictable threat might be a mechanism that contributes to increased anxiety in women.

Longitudinal increases in reward-related neural activity in early adolescence: Evidence from event-related potentials (ERPs).

Adolescence is frequently described as a developmental period characterized by increased sensitivity to rewards. However, previous research on age-related changes in the neural response to gains and losses have produced mixed results, with only some studies reporting potentiated neural responses during adolescence. The current study examined the ERP responses to gains and losses during a simple monetary reward (i.e., Doors) task in a large and longitudinal sample of 248 adolescent females assessed at two time points, separated by two years. At baseline, when the sample was 8- to 14-years-old, age related to larger (i.e., more positive) ERP responses to both gains and losses; moreover, age-related effects were stronger in relation to gains than losses. Overall, the amplitude of the ERP response to gains, but not losses, significantly increased from baseline to follow-up; however, this effect was moderated by age, such that reward-related ERPs only increased longitudinally among the younger participants. At the follow-up assessment, ERP responses to gains and losses were equally related to age. Collectively, these within- and between-subjects findings suggest a relatively specific developmental increase in reward-related neural activity during late childhood and early adolescence.