Abnormal neural responses to feedback in depressed adolescents

College students with depression symptom are more sensitive to task difficulty in reinforcement learning

BACKGROUND

Depression is usually characterized by impairments in reward function, and shows altered motivation to reward in reinforcement learning. This study further explored whether task difficulty affects reinforcement learning in college students with and without depression symptom.

METHODS

The depression symptom group (20) and the no depression symptom group (26) completed a probabilistic reward learning task with low, medium, and high difficulty levels, in which task the response bias to reward and the discriminability of reward were analyzed. Additionally, electrophysiological responses to reward and loss feedback were recorded and analyzed while they performed a simple gambling task.

RESULTS

The depression symptom group showed more response bias to reward than the no depression symptom group when the task was easy and then exhibited more quickly decrease in response bias to reward as task difficulty increased. The no depression symptom group showed a decrease in response bias only in the high-difficulty condition. Further regression analyses showed that, the Feedback-related negativity (FRN) and theta oscillation could predict response bias change in the low-difficulty condition, the FRN and oscillations of theta and delta could predict response bias change in the medium and high-difficulty conditions.

LIMITATIONS

The electrophysiological responses to loss and reward were not recorded in the same task as the reinforcement learning behaviors.

CONCLUSIONS

College students with depression symptom are more sensitive to task difficulty during reinforcement learning. The FRN, and oscillations of theta and delta could predict reward leaning behavior.

Reduced generalization of reward among individuals with subthreshold depression: Behavioral and EEG evidence

Altered stimulus generalization has been well-documented in anxiety disorders; however, there is a paucity of research investigating this phenomenon in the context of depression. Depression is characterized by impaired reward processing and heightened attention to negative stimuli. It is hypothesized that individuals with depression exhibit reduced generalization of reward stimuli and enhanced generalization of loss stimuli. Nevertheless, no study has examined this process and its underlying neural mechanisms. In the present study, we recruited 25 participants with subthreshold depression (SD group) and 24 age-matched healthy controls (HC group). Participants completed an acquisition task, in which they learned to associate three distinct pure tones (conditioned stimuli, CSs) with a reward, a loss, or no outcome. Subsequently, a generalization session was conducted, during which similar tones (generalization stimuli, GSs) were presented, and participants were required to classify them as a reward tone, a loss tone, or neither. The results revealed that the SD group exhibited reduced generalization errors in the early phase of generalization, suggesting a diminished ability to generalize reward-related stimuli. The event-related potential (ERP) results indicated that the SD group exhibited decreased generalization of positive valence to reward-related GSs and heightened generalization of negative valence to loss-related GSs, as reflected by the N1 and P2 components. However, the late positive potential (LPP) was not modulated by depression in reward generalization or loss generalization. These findings suggested that individuals with subthreshold depression may have a blunted or reduced ability to generalize reward stimuli, shedding light on potential treatment strategies targeting this particular process.

Reciprocal associations between affective decision-making and mental health in adolescence

Poor affective decision-making has been shown to associate cross-sectionally with poor mental health in clinical populations. However, evidence from general population samples is scarce. Moreover, whether decision-making is prospectively linked to mental health in youth in the general population and whether such associations are reciprocal have yet to be examined. The present study examined bidirectional associations between various aspects of affective decision-making and emotional and behavioural problems at ages 11 and 14 years in 13,366 members of the Millennium Cohort Study. Decision-making (delay aversion, deliberation time, quality of decision-making, risk adjustment, risk-taking) and emotional (emotional symptoms, peer problems) and behavioural (conduct problems, hyperactivity/inattention) problems were measured using the Cambridge Gambling Task and the Strengths and Difficulties Questionnaire, respectively. Results of cross-lagged panel models adjusted for confounding revealed a negative reciprocal association between hyperactivity and quality of decision-making but also positive reciprocal associations between conduct problems and delay aversion, and between peer problems and deliberation time. Emotional problems and peer problems predicted a decrease in risk-taking, conduct problems predicted an increase in risk-taking, and hyperactivity predicted an increase in delay aversion and deliberation time. Furthermore, hyperactivity and conduct problems predicted less risk adjustment, and risk adjustment predicted fewer peer problems. The results suggest that behavioural problems are prospectively linked to greater risk-taking and lower risk adjustment in adolescence. Moreover, adolescents with behavioural problems tend to make poorer decisions and be more delay-averse, but also poorer quality of decision-making and increased delay aversion are associated with more behavioural problems over time.

Need for cognition moderates the relief of avoiding cognitive effort

When making decisions, humans aim to maximize rewards while minimizing costs. The exertion of mental or physical effort has been proposed to be one those costs, translating into avoidance of behaviors carrying effort demands. This motivational framework also predicts that people should experience positive affect when anticipating demand that is subsequently avoided (i.e., a "relief effect"), but evidence for this prediction is scarce. Here, we follow up on a previous study [1] that provided some initial evidence that people more positively evaluated outcomes if it meant they could avoid performing an additional demanding task. However, the results from this study did not provide conclusive evidence that this effect was driven by effort avoidance. Here, we report two experiments that are able to do this. Participants performed a gambling task, and if they did not receive reward they would have to perform an orthogonal effort task. Prior to the gamble, a cue indicated whether this effort task would be easy or hard. We probed hedonic responses to the reward-related feedback, as well as after the subsequent effort task feedback. Participants reported lower hedonic responses for no-reward outcomes when high vs. low effort was anticipated (and later exerted). They also reported higher hedonic responses for reward outcomes when high vs. low effort was anticipated (and avoided). Importantly, this relief effect was smaller in participants with high need for cognition. These results suggest that avoidance of high effort tasks is rewarding, but that the size off this effect depends on the individual disposition to engage with and expend cognitive effort. They also raise the important question of whether this disposition alters the cost of effort per se, or rather offset this cost during cost-benefit analyses.

Working memory training for reward processing in university students with subsyndromal depression: The influence of baseline severity of depression

Previous studies have tentatively suggested that working memory training (WMT) has the potential to improve reward processing, but it is not known how long this improvement lasts, whether there is a lag effect, or whether it is reflected in neurophysiological indicators. In this study, 40 university students with subsyndromal depression were randomly assigned to a training group or a control group and completed a 20-day working memory training task and a simple memory task, respectively. All participants completed the Temporal Experience of Pleasure Scale (TEPS) and a doors task with electroencephalogram (EEG) signals recorded simultaneously on a pre- and post-test and a 3-month follow-up. The reward-related positivity (RewP) amplitude, theta power, and their differences between conditions (i.e., ΔRewP and Δtheta power, respectively) in the doors task were the primary outcomes, and the score on TEPS was the secondary outcome. The results indicated no group-related effects were demonstrated in primary and secondary outcomes at post-test and 3-month follow-up. Furthermore, the differences in the pre- and post-test in Δtheta power were moderated by the baseline severity of depression. This was primarily driven by the fact that the change values in the control group increased with the severity of depression, while the change values in the training group had high homogeneity. Our findings did not provide support for the effect of WMT on reward processing across the whole sample, but without intervention, there would be high heterogeneity in the change in the cognitive control ability to loss feedback, which is detrimental to individuals with high depression severity.

Acute stress selectively blunts reward anticipation but not consumption: An ERP study

Stress-induced dysfunction of reward processing is documented to be a critical factor associated with mental illness. Although many studies have attempted to clarify the relationship between stress and reward, few studies have investigated the effect of acute stress on the temporal dynamics of reward processing. The present study applied event-related potentials (ERP) to examine how acute stress differently influences reward anticipation and consumption. In this study, seventy-eight undergraduates completed a two-door reward task following a Trier Social Stress Task (TSST) or a placebo task. The TSST group showed higher cortisol levels, perceived stress, anxiety, and negative affect than the control group. For the control group, a higher magnitude of reward elicited a reduced cue-N2 but increased stimulus-preceding negativity (SPN), suggesting that controls were sensitive to reward magnitude. In contrast, these effects were absent in the stress group, suggesting that acute stress reduces sensitivity to reward magnitude during the anticipatory phase. However, the reward positivity (RewP) and P3 of both groups showed similar patterns, which suggests that acute stress has no impact on reward responsiveness during the consummatory phase. These findings suggest that acute stress selectively blunts sensitivity to reward magnitude during the anticipatory rather than the consummatory phase.

Positive valence system function and anhedonia in middle-aged and older adults at high suicide risk

Positive valence systems are disrupted in late-life depression and in individuals at risk for suicide. The reward positivity (RewP) is an event-related potential measure of positive valence system function that relates to depression and anhedonia in children and young adults. However, it is unclear whether a reliable RewP signal can be elicited in middle-aged and older adults at high risk for suicide and, if so, whether this signal is similarly associated with clinical symptoms. In the current study, a RewP was elicited with a standard gambling task in middle-aged and older adults (N = 31) at discharge from a hospitalization for suicidal thought or behaviors. The resulting electrocortical response differed significantly for monetary wins compared to losses. Internal reliability of the RewP and the feedback negativity (FN) to monetary loss was good to excellent. Internal reliability of difference measures was lower but still largely acceptable, with residualized differences scores demonstrating stronger reliability than subtraction-based scores. A smaller residualized RewP, after accounting for the influence of the FN, was associated with greater severity of lassitude, an index of appetitive anhedonia. These findings set the groundwork for future studies of positive valence system function and depression in middle-aged and older adults at high risk for suicide.

Alpha Event-Related Desynchronization During Reward Processing in Schizophrenia

BACKGROUND

Alterations in the brain's reward system may underlie motivation and pleasure deficits in schizophrenia (SZ). Neuro-oscillatory desynchronization in the alpha band is thought to direct resource allocation away from the internal state, to prioritize processing salient environmental events, including reward feedback. We hypothesized reduced reward-related alpha event-related desynchronization (ERD) in SZ, consistent with less externally focused processing during reward feedback.

METHODS

Electroencephalography was recorded while participants with SZ (n = 54) and healthy control participants (n = 54) played a simple slot machine task. Total alpha band power (8-14 Hz), a measure of neural oscillation magnitude, was extracted via principal component analysis and compared between groups and reward outcomes. The clinical relevance of hypothesized alpha power alterations was examined by testing associations with negative symptoms within the SZ group and with trait rumination, dimensionally, across groups.

RESULTS

A group × reward outcome interaction (p = .018) was explained by healthy control participants showing significant posterior-occipital alpha power suppression to wins versus losses (p < .001), in contrast to participants with SZ (p > .1). Among participants with SZ, this alpha ERD was unrelated to negative symptoms (p > .1). Across all participants, less alpha ERD to reward outcomes covaried with greater trait rumination for both win (p = .005) and loss (p = .002) outcomes, with no group differences in slope.

CONCLUSIONS

These findings demonstrate alpha ERD alterations in SZ during reward outcome processing. Additionally, higher trait rumination was associated with less alpha ERD during reward feedback, suggesting that individual differences in rumination covary with external attention to reward processing, regardless of reward outcome valence or group membership.

The modulation of pain in reward processing is reflected by increased P300 and delta oscillation

Pain elicits the desire for a reward to alleviate the unpleasant sensation. This may be a consequence of facilitated neural activities in the reward circuit. However, the temporal modulation of pain on reward processing remains unclear. We addressed this issue by recording electroencephalogram when participants received win or loss feedback in a simple gambling task. Pain treatment was conducted on 33 participants with topical capsaicin cream and on 33 participants with hand cream as a control. Results showed that pain generally increased the P300 amplitude for both types of feedback but did not affect feedback-related negativity (FRN). A significant interaction effect of treatment (painful, non-painful) and outcome (win, loss) was observed on delta oscillation as pain only enhanced the power of win feedback. In addition, the FRN and theta oscillation responded more to loss feedback, but this effect was unaffected by pain. These findings indicate that pain may enhance secondary value representation and evaluation processes of rewards, but does not influence primary distinction of reward or reward expectation. The temporal unfolding of how pain affects reward-related neural activities highlights the prominent impact of pain on high-level cognitive processes associated with reward.

Differences in cognitive processing between snakes and guns: Evidence from electroencephalography

The aim of the study is to explore differences in cognitive processing of phylogenetic and ontogenetic stimulus using the electroencephalography (EEG) technology. The researcher chose snakes and guns as representatives of phylogenetic stimulus and ontogenetic stimulus, respectively, and used the Oddball paradigm to present the experimental stimuli and explore the cognitive processing differences between them through time-domain analysis and time-frequency analysis. The results of time-domain analysis showed that snakes elicited larger N1, P2, and P3 amplitudes and a shorter P3 latency than guns and neutral stimuli, and that guns elicited greater P2 and P3 amplitudes than neutral stimuli. The findings of time-frequency analysis showed that the beta-band (320 - 420 ms, 25 - 35 Hz) power elicited by snakes was significantly greater than by guns and neutral stimuli, and that the beta-band power elicited by guns was significantly greater than by neutral stimuli. The results indicated that the brain has a cognitive processing advantage for both snakes and guns, which is more obvious for snakes than for guns, and that the brain is more sensitive to snakes.

The modulation of attentional deployment on emotional sensitivity to missed opportunity in depressive individuals: An event-related potential study

BACKGROUND

Depression affects individuals' physical and mental health seriously. It's important to explore the pathological mechanisms underlying depression. However, the emotional sensitivity to missed opportunity in depressive individuals and whether attentional deployment influences it remain unclear. The exploration of these questions could help to find novel approaches for the treatment of depression.

METHODS

Experiment 1 investigated the emotional sensitivity to missed opportunity in depressive participants during a sequential risk-taking task relative to healthy participants. Experiment 2 added attentional deployment manipulation to the task, i.e., inducing participants to focus on the positive or negative part of decision outcome, and investigated the modulation of attentional deployment on depressive participants' emotional sensitivity to missed opportunity and the neural mechanisms underlying this process by using EEG.

RESULTS

Depressive participants showed stronger emotional sensitivity to missed opportunity and LPP was a biomarker of this sensitivity. Moreover, focusing on the positive part of outcome reduced depressive participants' emotional sensitivity to missed opportunity effectively, and alpha power in the parietal area played a key role in this process.

CONCLUSIONS

The current study primarily revealed that depressive individuals were more sensitive to missed opportunity and attentional deployment was an effective way to modulate this sensitivity.

Impact of a mindfulness-based school curriculum on emotion processing in Vietnamese pre-adolescents: An event-related potentials study

The neurocognitive mechanisms associated with mindfulness training in children are not well understood. This randomised controlled study with active and passive control groups examined the impact of an 18-week mindfulness curriculum delivered by schoolteachers on emotion processing in Vietnamese 7- to 11-year-olds. Event-related potential markers indexed emotion processing while children were completing emotional Go/No-Go tasks before and after mindfulness training, and at 6-month follow-up. In an oddball Go/No-Go task with Caucasian faces no changes in P3b and LPP components were detected, but in a Go/No-Go task with Caucasian and Japanese faces changes were observed in P3b latencies and LPP mean amplitudes. Specifically, the P3b in response to angry non-targets for Japanese faces peaked later in the mindfulness training group (TG) at 6-months follow-up in comparison to the non-intervention control group (NCG). The LPP mean amplitudes for averaged Caucasian and Japanese angry non-targets were also attenuated in the TG at 6-month follow-up. In contrast, no changes in the LPP mean amplitudes were observed for the NCG over time. Together, these findings may indicate that mindfulness training in pre-adolescents enhances emotional non-reactivity to negative distractors. A fluctuating pattern of LPP mean amplitude modulations for angry targets was observed in the active control group (ACG) receiving social-emotional learning (SEL) training. Overall, findings from this study suggest that mindfulness training in pre-adolescents enhances emotional non-reactivity to negative distractors and some of the effects are culturally sensitive.

Emotion Context Insensitivity is generalized in individuals with major depressive disorder but not in those with subclinical depression

BACKGROUND

Depressed individuals experience deficits in emotional reactivity. One well-established theory is the Emotion Context Insensitivity (ECI) theory. To better understand impairments in emotional reactivity, we investigated whether the ECI theory is applicable to anticipatory, consummatory, and remembered affect, in both clinical and subclinical depression.

METHODS

Participants were divided into four groups: Major Depressive Disorder Group (MDD, N = 60), Control Group for MDD (Control_MDD, N = 50), Subclinical Depression Group (SD, N = 56), and Control Group for SD (Control_SD, N = 56). The Hamilton Depression Rating Scale and the Beck Depression Inventory were used to assess the severity of depression and anhedonia symptoms. The Monetary Incentive Delay Task evaluated participants' affective responses towards monetary stimuli.

RESULTS

The MDD group was more insensitive to both monetary reward and loss across most types of affect than was the control group. Compared with the controls, the SD group exhibited lower reactivity in anticipatory positive affect but enhanced reactivity in consummatory positive, anticipatory, and remembered negative affect.

LIMITATIONS

Emotional affect was evaluated by subjective ratings, which may lack objectivity. Additionally, laboratory settings and monetary rewards used in this study may cause the results less generalized to daily life and to other types of rewards.

CONCLUSION

The pattern of emotional reactivity in the MDD group was partly consistent with the ECI theory, whereas the SD group showed greater arousal and instability of emotional reactions. These different patterns could facilitate the understanding of emotional reactivity and develop further treatments across the course of depression.

State-independent and -dependent behavioral and neuroelectrophysiological characteristics during dynamic decision-making in patients with current and remitted depression

BACKGROUND

It is unclear whether the altered decision-making (DM) observed in patients with major depressive disorder (MDD) is neurophysiological and whether it improves with remission of depressive symptoms. The aim of this study was to identify developmental patterns of DM behavior, related cognitive characteristics, and electrophysiological abnormalities in patients with MDD across clinical stages.

METHODS

A sample of 48 first-episode MDD patients (FD group), 41 remitted MDD patients (RD group), and 43 healthy controls (HCs) completed psychometric assessments and performed the balloon analogue risk task (BART) while event-related potentials (ERPs) were recorded.

RESULTS

The RD group had lower depressiveness, self-blame, rumination, and catastrophizing tendencies, and higher mental resilience scores than the FD group, but retained significant differences from HCs. MDD patients showed a more conservative DM strategy than HCs, with no significant difference between the FD and RD groups. Compared to the FD group, the RD group had a smaller FRN for negative feedback and a trend toward a smaller P3 for positive feedback. Compared with HCs, the RD group had a smaller P3 during the positive feedback phase. FRN amplitude correlated positively with depression level and negatively with mental resilience.

LIMITATIONS

Because a comparative cross-section design was employed, longitudinal studies are needed to make causal inferences.

CONCLUSION

MDD patients presented a stable risk-avoidance bias in actively depressed and remission periods, consistent with a state-independent impairment pattern. Significantly reduced FRN amplitudes during remission indicated a state-dependent impairment pattern, and FRN amplitudes correlated with depression level. An abnormal feedback P3 component may be a state-independent characteristic that may become more pronounced with MDD progression.

Disentangling performance-monitoring signals encoded in feedback-related EEG dynamics

The feedback-related negativity (FRN) is a well-established electrophysiological correlate of feedback-processing. However, there is still an ongoing debate whether the FRN is driven by negative or positive reward prediction errors (RPE), valence of feedback, or mere surprise. Our study disentangles independent contributions of valence, surprise, and RPE on the feedback-related neuronal signal including the FRN and P3 components using the statistical power of a sample of N = 992 healthy individuals. The participants performed a modified time-estimation task, while EEG from 64 scalp electrodes was recorded. Our results show that valence coding is present during the FRN with larger amplitudes for negative feedback. The FRN is further modulated by surprise in a valence-dependent way being more positive-going for surprising positive outcomes. The P3 was strongly driven by both global and local surprise, with larger amplitudes for unexpected feedback and local deviants. Behavioral adaptations after feedback and FRN just show small associations. Results support the theory of the FRN as a representation of a signed RPE. Additionally, our data indicates that surprising positive feedback enhances the EEG response in the time window of the P3. These results corroborate previous findings linking the P3 to the evaluation of PEs in decision making and learning tasks.

Psychological Dimensions Relevant to Motivation and Pleasure in Schizophrenia

Motivation and pleasure deficits are common in schizophrenia, strongly linked with poorer functioning, and may reflect underlying alterations in brain functions governing reward processing and goal pursuit. While there is extensive research examining cognitive and reward mechanisms related to these deficits in schizophrenia, less attention has been paid to psychological characteristics that contribute to resilience against, or risk for, motivation and pleasure impairment. For example, psychological tendencies involving positive future expectancies (e.g., optimism) and effective affect management (e.g., reappraisal, mindfulness) are associated with aspects of reward anticipation and evaluation that optimally guide goal-directed behavior. Conversely, maladaptive thinking patterns (e.g., defeatist performance beliefs, asocial beliefs) and tendencies that amplify negative cognitions (e.g., rumination), may divert cognitive resources away from goal pursuit or reduce willingness to exert effort. Additionally, aspects of sociality, including the propensity to experience social connection as positive reinforcement may be particularly relevant for pursuing social goals. In the current review, we discuss the roles of several psychological characteristics with respect to motivation and pleasure in schizophrenia. We argue that individual variation in these psychological dimensions is relevant to the study of motivation and reward processing in schizophrenia, including interactions between these psychological dimensions and more well-characterized cognitive and reward processing contributors to motivation. We close by emphasizing the value of considering a broad set of modulating factors when studying motivation and pleasure functions in schizophrenia.

Aberrant social feedback processing and its impact on memory, social evaluation, and decision-making among individuals with depressive symptoms

BACKGROUND

Depression is associated with aberrant social feedback processing. However, little is known about the impact of these deficits on individuals' memory, social evaluation, and social decision-making.

METHODS

We examined event-related potentials (ERPs) during the processing of social feedback with different emotional valences and intensities, among individuals with high and low depressive symptoms. After three days, participants performed a recall test, along with social evaluation and money allocation.

RESULTS

Compared with the control group, participants with depressive symptoms showed larger occipital P1 and parietal P3 amplitudes to negative social feedback, as well as larger frontal feedback-related negativity toward highly positive social feedback; this indicates toward altered attentional allocation, encoding, and anticipation in social feedback processing. After three days of social feedback processing, individuals in the depressive symptom group recalled negative social feedback better and gave less positive evaluations and allocated less money to the senders of highly negative social feedback compared with control group participants. Notably, ERPs predicted subsequent memory, social evaluation, and decision-making, suggesting a significant impact of aberrant social feedback processing on social cognition and behaviors in depression.

LIMITATIONS

Individuals with depressive symptoms rather than patients with depressive disorders were recruited and therefore caution is needed in applying the findings to clinical populations.

CONCLUSIONS

Individuals with depressive symptoms exhibit negative bias in anticipation, attentional allocation, and encoding processes during social feedback processing, which further influences their memory, social evaluation, and social decision-making in the long run. These aberrant biases should be targeted to prevent the development of major depressive disorders.

Amphetamine alters an EEG marker of reward processing in humans and mice

The bench-to-bedside development of pro-cognitive therapeutics for psychiatric disorders has been mired by translational failures. This is, in part, due to the absence of pharmacologically sensitive cognitive biomarkers common to humans and rodents. Here, we describe a cross-species translational marker of reward processing that is sensitive to the aminergic agonist, d-amphetamine. Motivated by human electroencephalographic (EEG) findings, we recently reported that frontal midline delta-band power is an electrophysiological biomarker of reward surprise in humans and in mice. In the current series of experiments, we determined the impact of parametric doses of d-amphetamine on this reward-related EEG response from humans (n = 23) and mice (n = 28) performing a probabilistic learning task. In humans, d-amphetamine (placebo, 10 mg, 20 mg) boosted the Reward Positivity event-related potential (ERP) component as well as the spectral delta-band representations of this signal. In mice, d-amphetamine (placebo, 0.1 mg/kg, 0.3 mg/kg, 1.0 mg/kg) boosted both reward and punishment ERP features, yet there was no modulation of spectral activities. In sum, the present results confirm the role of dopamine in the generation of the Reward Positivity in humans, and pave the way toward a pharmacologically valid biomarker of reward sensitivity across species.

Different depression: motivational anhedonia governs antidepressant efficacy in Huntington's disease

Depression is more common in neurodegenerative diseases such as Huntington's disease than the general population. Antidepressant efficacy is well-established for depression within the general population: a recent meta-analysis showed serotonin norepinephrine reuptake inhibitors, tricyclic antidepressants and mirtazapine outperformed other antidepressants. Despite the severe morbidity, antidepressant choice in Huntington's disease is based on Class IV evidence. We used complementary approaches to determine treatment choice for depression in Huntington's disease: propensity score analyses of antidepressant treatment outcome using the ENROLL-HD data set, and a dissection of the cognitive mechanisms underlying depression in Huntington's disease using a cognitive battery based on the Research Domain Criteria for Depression. Study 1 included ENROLL-HD 5486 gene-positive adult patients started on an antidepressant medication for depression. Our outcome measures were depression (Hospital Anxiety and Depression Scale or Problem Behaviours Assessment 'Depressed Mood' item) at first follow-up (primary outcome) and all follow-ups (secondary outcome). The intervention was antidepressant class. We used Svyglm&Twang in R to perform propensity scoring, using known variables (disease progression, medical comorbidity, psychiatric morbidity, sedatives, number of antidepressants, demographics and antidepressant contraindications) to determine the probability of receiving different antidepressants (propensity score) and then included the propensity score in a model of treatment efficacy. Study 2 recruited 51 gene-positive adult patients and 26 controls from the South Wales Huntington's Disease Management Service. Participants completed a motor assessment, in addition to measures of depression and apathy, followed by tasks measuring consummatory anhedonia, motivational anhedonia, learning from reward and punishment and reaction to negative outcome. We used generalised linear models to determine the association between task performance and depression scores. Study 1 showed selective serotonin reuptake inhibitors outperformed serotonin norepinephrine reuptake inhibitors on the primary outcome (P = 0.048), whilst both selective serotonin reuptake inhibitors (P = 0.00069) and bupropion (P = 0.0045) were superior to serotonin norepinephrine reuptake inhibitors on the secondary outcome. Study 2 demonstrated an association between depression score and effort for reward that was not explained by apathy. No other mechanisms were associated with depression score. We found that selective serotonin reuptake inhibitors and bupropion outperform serotonin norepinephrine reuptake inhibitors at alleviating depression in Huntington's disease. Moreover, motivational anhedonia appears the most significant mechanism underlying depression in Huntington's disease. Bupropion is improves motivational anhedonia and has a synergistic effect with selective serotonin reuptake inhibitors. This work provides the first large-scale, objective evidence to determine treatment choice for depression in Huntington's disease, and provides a model for determining antidepressant efficacy in other neurodegenerative diseases.

Win, lose, or draw: Examining salience, reward memory, and depression with the reward positivity

The reward positivity (RewP) is a putative biomarker of depression. Careful control of stimulus properties and manipulation of both stimulus valence and salience could facilitate interpretation of the RewP. RewP interpretation could further be improved by investigating functional outcomes of a blunted RewP in depression, such as reduced memory for rewarding outcomes. This study sought to advance RewP interpretation first by advancing task design through use of neutral (i.e., draw) control trials and counterbalanced feedback stimuli. Second, we examined the RewP's association with memory and the impact of depression. Undergraduates completed self-report measures of depression and anhedonia prior to a modified doors task in which words were displayed in colored fonts that indicated win, loss, or draw feedback. Memory of the feedback associated with each word (i.e., source memory) was tested. Results showed that RewP response to wins was more positive than to losses, which was more positive than to draws. The RewP was not associated with depression or anhedonia. The low depression group showed a source memory advantage for win words, but the high depression group did not. Source memory showed small relations to the RewP, but these did not survive Bonferroni correction. Results suggest the RewP is sensitive to salience and highlight challenges in detecting an association between the RewP and depression in modified doors tasks. Findings indicate that depression is related to dysfunctional source memory for reward but not loss and that future research should probe the possible associations between the RewP and memory in depression.

Investigation of reward learning and feedback sensitivity in non-clinical participants with a history of early life stress

Early life stress (ELS) is an important risk factor for the development of depression. Impairments in reward learning and feedback sensitivity are suggested to be an intermediate phenotype in depression aetiology therefore we hypothesised that healthy adults with a history of ELS would exhibit reward processing deficits independent of any current depressive symptoms. We recruited 64 adults with high levels of ELS and no diagnosis of a current mental health disorder and 65 controls. Participants completed the probabilistic reversal learning task and probabilistic reward task followed by depression, anhedonia, social status, and stress scales. Participants with high levels of ELS showed decreased positive feedback sensitivity in the probabilistic reversal learning task compared to controls. High ELS participants also trended towards possessing a decreased model-free learning rate. This was coupled with a decreased learning ability in the acquisition phase of block 1 following the practice session. Neither group showed a reward induced response bias in the probabilistic reward task however high ELS participants exhibited decreased stimuli discrimination. Overall, these data suggest that healthy participants without a current mental health diagnosis but with high levels of ELS show deficits in positive feedback sensitivity and reward learning in the probabilistic reversal learning task that are distinct from depressed patients. These deficits may be relevant to increased depression vulnerability.

Hypersensitivity to negative feedback during dynamic risky-decision making in major depressive disorder: An event-related potential study

BACKGROUND

Patients with major depressive disorder (MDD) exhibit a diminished ability to think or concentrate, indecisiveness, and altered sensitivity to reward and punishment. These impairments can influence complex risk-related decision-making in dynamic environments. The neurophysiological mechanisms mediating MDD effects on decision-making behavior are not well understood.

METHODS

Patients with MDD (N=50) and healthy controls (HC, N=40) were enrolled. They completed a series of psychometric tests. Event-related potentials (ERPs) were recorded during the performance of a well-validated modified version of Balloon Analogue Risk Task (BART).

RESULTS

BART behavior data were similar across the two groups except the MDD patients showed more stability of risk aversion. Neurophysiologically, BART losses generated larger P3 amplitudes than wins, and MDD patients had larger feedback-related negativity (FRN) components than HCs in response to negative feedback (losses). Greater FRN amplitudes in response to losses correlated with higher levels of depressiveness, psychological pain, and anhedonia. A longer FRN latency in MDD patients was associated with more severe suicidal ideation.

LIMITATIONS

The findings are based on cross-sectional data, which are not powerful enough to make causal inferences.

CONCLUSION

MDD patients exhibit enhanced FRNs in the frontocentral region after receiving negative feedback in a risky decision-making task. FRN magnitude is associated with depressive symptom severity. Punishment hypersensitivity may contribute to the maintenance of depressive symptoms in MDD patients, and FRN may be a useful index of such hypersensitivity.

The neural habituation to hedonic and eudaimonic rewards: Evidence from reward positivity

Rewards play an important role in people's well-being. However, the mechanisms underlying neural habituation to hedonic rewards (attainment of pleasure) and eudaimonic rewards (attainment of meaning and self-realization) and their implications for longitudinal changes in well-being remain unknown. By operationalizing hedonic rewards as "winning money for oneself" and eudaimonic rewards as "winning money for a charity", 78 participants (41 women, aged from 17 to 24 years) completed a revised monetary gambling task during event-related potential (ERP) recording. Subsequently, the participants' well-being was measured after one year. The results showed that the reward positivity (RewP) effect readily decreased as the hedonic rewards were repeated, whereas the RewP effect in response to eudaimonic rewards was relatively sustained over time. Moreover, the declining RewP effect for repeated eudaimonic rewards was marginally positively associated with longitudinal decreases in well-being. These findings demonstrate at the neural level that sensitivity to repeated hedonic rewards is more prone to decrease than sensitivity to repeated eudaimonic rewards, and sustained eudaimonic reward sensitivity in the short term has greater implications for changes in well-being in the long term.

Depressive rumination is correlated with brain responses during self-related processing

BACKGROUND

Rumination, a tendency to focus on negative self-related thoughts, is a central symptom of depression. Studying the self-related aspect of such symptoms is challenging because of the need to distinguish self effects from the emotional content of task stimuli. This study employed an emotionally neutral self-related paradigm to investigate possible altered self-processing in depression and its link to rumination.

METHODS

People with major depressive disorder (n = 25) and controls (n = 25) underwent task-based electro-encephalogram recording. We studied late event-related potentials, along with low-frequency oscillatory power. We compared electroencephalogram metrics between groups and correlated them with depressive symptoms and reported rumination.

RESULTS

Participants with major depressive disorder displayed a difference in late positive potentials across frontocentral electrodes between self-related and non-self-related conditions. We found no such difference in controls. The magnitude of this difference was positively correlated with depressive symptoms and reported rumination. Participants with major depressive disorder also had elevated theta oscillation power at central electrodes in self-related conditions, a finding that we did not see in controls.

LIMITATIONS

Patients with major depressive disorder were medicated at the time of the study. The group studied was primarily female, so the observed effects may have been sex-specific.

CONCLUSION

Rumination appears to be linked to altered self-related processing in depression, independent of stimuli-related emotional confounds. This connection between self-related processing and depression may point to a self disorder as a core component of depression.

Electrophysiological biomarkers of behavioral dimensions from cross-species paradigms

There has been a fundamental failure to translate preclinically supported research into clinically efficacious treatments for psychiatric disorders. One of the greatest impediments toward improving this species gap has been the difficulty of identifying translatable neurophysiological signals that are related to specific behavioral constructs. Here, we present evidence from three paradigms that were completed by humans and mice using analogous procedures, with each task eliciting candidate a priori defined electrophysiological signals underlying effortful motivation, reinforcement learning, and cognitive control. The effortful motivation was assessed using a progressive ratio breakpoint task, yielding a similar decrease in alpha-band activity over time in both species. Reinforcement learning was assessed via feedback in a probabilistic learning task with delta power significantly modulated by reward surprise in both species. Additionally, cognitive control was assessed in the five-choice continuous performance task, yielding response-locked theta power seen across species, and modulated by difficulty in humans. Together, these successes, and also the teachings from these failures, provide a roadmap towards the use of electrophysiology as a method for translating findings from the preclinical assays to the clinical settings.

Reward mechanism of depressive episodes in bipolar disorder: Enhanced theta power in feedback-related negativity

INTRODUCTION

This study aimed to explore the reward-related neural mechanism in patients with depressive mood in bipolar disorder (BD) using event-related potentials. It remains unknown whether or not different neurobiological markers underlying depression symptoms in BD depression and major depression disorder (MDD).

METHODS

24 patients with BD depression and 20 healthy controls were included. Participants underwent evaluation with the Temporal Experience of Pleasure Scale (TEPS), followed by the classical gambling paradigm, while undergoing 64-channel electroencephalography. The waveform of feedback-related negativity (FRN) was extracted from the 250-350 ms time-window after participants received feedback regarding loss or gain. Event-related potential datasets were obtained using time-frequency analysis.

RESULTS

(1) The TEPS scores of the patients were significantly lower than those of the controls [t₍₄₂₎ = 5.16, p < 0.01]. (2) The event of loss elicited a deeper FRN in patients than that in controls [t₍₄₂₎ = 2.19, p < 0.05], while no difference was observed in the event of gains (t₍₄₂₎ = 1.12, p > 0.05). (3) Theta power rooted in FRN in patients was significantly higher in loss than in gain [F_(1,42) = 30.32, p < 0.01]. (4) Analysis of Variance (ANOVA) illustrated the interaction effect of theta power in gain/loss between two groups [F_(1,42) = 3.59, p = 0.06].

LIMITATION

Our study did not analyze the effect of different drugs which might affect our results.

CONCLUSION

The enhanced reflection of negative feedback was consistent with the negative bias, impulse control impairment, and emotional dysregulation observed in the bipolar disorder spectrum. We suggested that the extreme theta power generated from the anterior cingulate gyrus (ACC) might be the main component of abnormal FRN.

Cannabis users demonstrate enhanced neural reactivity to reward: An event-related potential and time-frequency EEG study

INTRODUCTION

Disruptions in neural measures of reward responsiveness are implicated in risk for and the development of Substance Use Disorders (SUDs) in general, but it is not clear if this is also true for Cannabis Use Disorder (CUD). To date, no studies have examined neural reward responsiveness in cannabis users using EEG.

METHODS

Cannabis users (CU; n = 67) and non-users (n = 60) were drawn from larger studies of individuals with and without internalizing and externalizing psychopathology. Groups were matched on current and lifetime psychopathology. Participants completed a validated monetary reward task during electroencephalogram (EEG). One-way between subject analysis of covariance (ANCOVA) models examined group differences in four EEG indicators of reward responsiveness - the reward positivity (RewP) and feedback negativity (FN) event-related potentials and two time-frequency measures (reward-related delta and loss-related theta).

RESULTS

CU demonstrated an enhanced RewP to the attainment of monetary reward compared to non-users (p = .004), even after controlling for relevant covariates. Secondary analyses found that occasional CU, but not current CUD or remitted CUD, showed enhanced RewP compared to non-users. There were no significant differences in FN, reward-related delta, or loss-related theta time-frequency measures between groups.

CONCLUSIONS

To our knowledge, this is the first study to show preliminary evidence that CU have an enhanced RewP to reward and the extent of disruption may be related to CUD status. Our findings suggest that greater neural reward responsiveness may only be seen among occasional CU, not necessarily among CU with current or remitted CUD.

Emotion context insensitivity in depression: Toward an integrated and contextualized approach

Major depressive disorder (MDD) is characterized by pervasive mood disturbance as well as deficits in emotional processing, reactivity, and regulation. There is accumulating evidence that MDD is characterized by emotional patterns consistent with environmental disengagement, as reflected in attenuated positive and negative emotional reactivity, consistent with Emotion Context Insensitivity (ECI) theory. However, MDD individuals vary considerably in the extent to which they exhibit specific alterations in patterns of emotional responding. Emotions are complex, multicomponent processes that invoke responses across multiple functional domains and levels of analysis, including subjective experience, behavior, autonomic regulation, cognition, and neural processing. In this article, I review the current state of the literature on emotional responding and MDD from the lens of ECI. I focus on the importance of assessing emotional indices from multiple levels of analysis across development and contexts. I also discuss methodological and measurement issues that may contribute to inconsistent findings. In particular, I emphasize how psychophysiological measures can help elucidate emotional processes that underlie the pathophysiology of MDD as part of an integrated and contextualized approach.

Neural Indicators of Anhedonia: Predictors and Mechanisms of Treatment Change in a Randomized Clinical Trial in Early Childhood Depression

BACKGROUND

Early childhood depression is associated with anhedonia and reduced event-related potential (ERP) responses to rewarding or pleasant stimuli. Whether these neural measures are indicators of target engagement or treatment outcome is not yet known.

METHODS

We measured ERP responses to win and loss feedback in a guessing task and to pleasant versus neutral pictures in young (4.0-6.9 years of age) depressed children before and after randomization to either 18 weeks of Parent-Child Interaction Therapy-Emotion Development (PCIT-ED) or waitlist.

RESULTS

Analyses included reward positivity (RewP) data from 118 children randomly assigned to PCIT-ED (n = 60) or waitlist (n = 58) at baseline and late positive potential (LPP) data from 99 children (44 assigned to PCIT-ED vs. 55 assigned to waitlist) at baseline. Children undergoing PCIT-ED showed a greater reduction in anhedonia (F_1,103 = 10.32, p = .002, partial η² = .09). RewP reward responses increased more (F_1,86 = 5.98, p = .02, partial η² = .07) for PCIT-ED, but a greater change in RewP was not significantly associated with a greater reduction in major depressive disorder symptoms (r = -.12, p > .4). Baseline RewP did not predict treatment change. LPPs to positive pictures did not change across treatment, but greater baseline LPPs to positive pictures predicted a higher likelihood of remission from major depressive disorder in children undergoing PCIT-ED (B = 0.14; SE = 0.07; odds ratio = 1.15; p = .03).

CONCLUSIONS

The ERP reward response improved in young children with depression during a treatment designed to enhance emotion development, providing evidence of target engagement of the neural systems associated with reward. Further, greater baseline LPP responses to positive pictures was associated with a greater likelihood of depression remission, suggesting that this ERP measure can predict which children are most likely to respond to treatment.

The ERP, frequency, and time-frequency correlates of feedback processing: Insights from a large sample study

Human learning, at least in part, appears to be dependent on the evaluation of how outcomes of our actions align with our expectations. Over the past 23 years, electroencephalography (EEG) has been used to probe the neural signatures of feedback processing. Seminal work demonstrated a difference in the human event-related potential (ERP) dependent on whether people were processing correct or incorrect feedback. Since then, these feedback evoked ERPs have been associated with reinforcement learning and conflict monitoring, tied to subsequent behavioral adaptations, and shown to be sensitive to a wide range of factors (e.g., Parkinson's disease). Recently, research has turned to frequency decomposition techniques to examine how changes in the EEG power spectra are related to underlying learning mechanisms. Although the literature on the neural correlates of feedback processing is vast, there are still methodological discrepancies and differences in results across studies. Here, we provide reference results and an investigation of methodological considerations for the ERP (reward positivity) and frequency (delta and theta power) correlates of feedback evaluation with a large sample size. Specifically, participants (n = 500) performed a two-armed bandit task while we recorded EEG. Our findings provide key information about the data characteristics and relationships that exist between the neural signatures of feedback evaluation. Additionally, we conclude with selected methodological recommendations for standardization of future research. All data and scripts are freely provided to facilitate open science.

Social Feedback Valence Differentially Modulates the Reward Positivity, P300, and Late Positive Potential

Abnormal social or reward processing is associated with several mental disorders. Although most studies examining reward processing have focused on monetary rewards, recent research also has tested neural reactivity to social rewards (e.g., positive social feedback). However, the majority of these studies only include two feedback valences (e.g., acceptance, rejection). Yet, social evaluation is rarely binary (positive vs. negative) and people often give 'on the fence' or neutral evaluations of others. Processing of this type of social feedback may be ambiguous and impacted by factors such as psychopathology, self-esteem, and prior experiences of rejection. Thus, the present study probed the reward positivity (RewP), P300, and late positive potential (LPP) following acceptance, rejection, and "one the fence" [between acceptance and rejection] feedback in undergraduate students (n = 45). Results indicated that the RewP showed more positive amplitudes following acceptance compared to both rejection and "on the fence" feedback, and the RewP was larger (i.e., more positive) following rejection relative to "on the fence" feedback. In contrast, the P300 did not differ between rejection and "on the fence" feedback, and both were reduced compared to acceptance. The LPP was blunted in response to rejection relative to acceptance and "on the fence" feedback (which did not differ from each other). Exploratory analyses demonstrated that greater self-reported rejection sensitivity was associated with a reduced LPP to acceptance. Taken together, these findings suggest that the neural systems underlying the RewP, P300, and LPP may evaluate "on the fence" social feedback differently, and that individuals high on rejection sensitivity may exhibit reduced attention toward and elaborative processing of social acceptance.

Aiming at ecological validity-Midfrontal theta oscillations in a toy gun shooting task

Laboratory electroencephalography (EEG) studies have already provided important insights into the neuronal mechanisms of performance monitoring. However, to our knowledge no study so far has examined neuronal correlates of performance monitoring using an ecologically valid task outside a typical laboratory setting. Therefore, we examined midfrontal theta and the feedback-related negativity (FRN) using mobile EEG in a physical shooting task within an ecologically valid environment with highly dynamical visual feedback. Participants shot a target using a toy gun while moving and looking around freely. Shots that missed the target evoked stronger midfrontal theta activity than hits and this response was rather phase-unlocked. There was no difference between misses and hits in the FRN. The results raise the question whether the absence of certain ERP components like the FRN could be due to methodological reasons or to the fact that partially different neuronal processes may be activated in the laboratory as compared to more ecologically valid tasks. Overall, our results indicate that crucial neurocognitive processes of performance monitoring can be assessed in highly dynamic and ecologically valid settings by mobile EEG.

Reward-Related Neural Predictors and Mechanisms of Symptom Change in Cognitive Behavioral Therapy for Depressed Adolescent Girls

BACKGROUND

Approximately half of depressed adolescents fail to respond to cognitive behavioral therapy (CBT). Given the variability in response, it is important to identify pretreatment characteristics that predict prognosis. Knowledge of which depressed adolescents are likely to exhibit a positive versus poor outcome to CBT may have important clinical implications (e.g., informing treatment recommendations). Emerging evidence suggests that neural reward responsiveness represents one promising predictor.

METHODS

Adolescents with major depressive disorder (n = 36) received CBT and completed a reward task at 3 time points (pretreatment, midtreatment and posttreatment) while 128-channel electroencephalographic data were acquired. Healthy control participants (n = 29) completed the same task at 3 corresponding time points. Analyses focused on event-related potentials linked to 2 stages of neural processing: initial response to rewards (reward positivity) and later, elaborative processing (late positive potential). Moreover, time-frequency analyses decomposed the reward positivity into 2 constituent components: reward-related delta and loss-related theta activity.

RESULTS

Multilevel modeling revealed that greater pretreatment reward responsiveness, as measured by the late positive potential to rewards, predicted greater depressive symptom change. In addition, a group × condition × time interaction emerged for theta activity to losses, reflecting normalization of theta power in the group with major depressive disorder from baseline to posttreatment.

CONCLUSIONS

An event-related potential measure of sustained (late positive potential)-but not initial (reward positivity)-reward responsiveness predicted symptom improvement, which may help inform which depressed adolescents are most likely to benefit from CBT. In addition to alleviating depression, successful CBT may attenuate underlying neural (theta) hypersensitivity to negative outcomes in depressed youths.

Here's looking at you, kid? Maternal depression and adolescent attention to self- or other-directed emotional faces

BACKGROUND

Maternal depression history represents a significant risk factor for developing psychopathology in children, altered emotional responding may represent a central risk pathway. However, additional research is needed on factors that affect the strength or direction of response alterations in relation to depression-risk in youth. In particular, facial orientation and gaze direction may alter personal relevance, with emotions directed towards an individual heightening motivational salience, compared to emotions directed away.

METHODS

Mother-daughter dyads (N = 56) were recruited based on presence or absence of maternal depression history and absence of youth depression. In line with theoretical perspectives suggesting diminished sensitivity to emotional context in relation to depression risk, we examined three Event-Related Potential (ERP) components in relation to forward versus averted emotional faces in a sample of girls with and without a maternal history of depression: the N200, N400, and Late Positive Potential (LPP).

RESULTS

Results showed a significant maternal depression history by face-orientation effect. Low-risk girls exhibited more negative N200 and N400 amplitudes for straight (M = -3.72, SE = 0.83; M = -3.57, SE = 0.86) versus averted (M = -2.15, SE = 0.76; M = -1.68, SE = 0.81) faces, while girls of mothers with histories of depression showed undifferentiated N200 or N400 responses in relation to face orientation. For LPP amplitudes, low-risk girls exhibited significantly more positive LPP amplitudes than high-risk girls, but only for averted faces (M = 0.69, SE = 0.59 and M = -2.63, SE = 0.74, respectively).

LIMITATIONS

Cross-sectional design and limited sample.

CONCLUSIONS

Results indicate that familial depression risk is associated with altered responsivity to face-orientation, these were interpreted as representing differential sensitivity to the personal-relevance of emotional stimuli.

Self-affirmation enhances the processing of uncertainty: An event-related potential study

We proposed that self-affirmation can endow people with more cognitive resource to cope with uncertainty. We tested this possibility with an event-related potential (ERP) study by examining how self-affirmation influences ambiguous feedback processing in a simple gambling task, which was used to investigate risk decision-making. We assigned 48 participants randomly to the affirmation and non-affirmation (i.e., control) groups. All participants accepted the manipulation first and then completed the gambling task with an electroencephalogram (EEG) recording, in which participants might receive a positive (winning), negative (losing), or ambiguous (unknown valence) outcome after they made a choice. We considered both the feedback-related negativity (FRN) and P3 components elicited by the outcome feedback, which reflected the amount of cognitive resources being invested in the early and late stages of the outcome feedback processing, respectively. ERP results showed that ambiguous feedback elicited a larger FRN among affirmed participants than unaffirmed participants but exerted no influence on the P3. This finding suggests that self-affirmation may help coping with uncertainty by enhancing the early processing of uncertainty.

Reward Responsiveness in Suicide Attempters: An Electroencephalography/Event-Related Potential Study

BACKGROUND

The present study aimed to objectively examine the Research Domain Criteria (RDoC) subconstructs of reward anticipation and initial response to reward in adult suicide attempters, compared with nonattempters, using electroencephalography (EEG) and event-related potentials (ERPs) within the context of the RDoC-recommended experimental paradigms for these subconstructs.

METHODS

Participants had either a history of at least 1 suicide attempt (n = 30) or no history of attempting suicide (n = 30). They completed diagnostic interviews, self-report questionnaires, and 2 computer-based tasks-the monetary incentive delay task and the doors task-during which continuous EEG was recorded. Temporospatial principal component analysis was used to isolate each of the ERP components of interest from other temporally or spatially overlapping components. Exploratory time-frequency analyses were also conducted to supplement the ERP analyses.

RESULTS

Suicide attempters, compared with nonattempters, exhibited specific deficits in reward anticipation (i.e., blunted cue-P3 ERP during the monetary incentive delay task) and in initial response to reward (i.e., reduced feedback-related delta power in the gain condition of the doors task). These results were at least partially independent of current symptoms or diagnoses of depression and anxiety.

CONCLUSIONS

These findings constitute an important step in obtaining a more fine-grained understanding of the specific reward-related abnormalities that might contribute to suicide risk.

Emotional Contexts Modulate Anticipatory Late Positive Component and Reward Feedback Negativity in Adolescents With Major Depressive Disorder

BACKGROUND

Neuroimaging research has determined deficits in the dopaminergic circuit of major depressive disorder (MDD) during adolescence. This study investigated how emotional contexts modulate the temporal dynamics of reward anticipation and feedback in adolescents.

METHODS

EEG data from 35 MDD and 37 healthy adolescents were recorded when they conducted a gambling task after being presented with emotional pictures.

RESULTS

The results demonstrated that both MDD and healthy adolescents exhibited the largest late positive component (LPC) in positive contexts at the frontal sites and the largest LPC in negative contexts at the central sites; however, MDD adolescents exhibited anticipatory LPC hypoactivation than healthy adolescents. However, MDD adolescents exhibited smaller gain feedback negativity (FN) than healthy adolescents independent of emotional contexts, positively correlating with the trait anhedonia according to the consummatory aspect of the Temporal Experience of Pleasure Scale. In contrast, MDD adolescents exhibited greater FN loss in positive and neutral contexts than healthy adolescents while no difference in FN loss was found between the two groups in negative contexts. Moreover, the FN loss amplitudes negatively correlated with hedonic tone according to the Snaith-Hamilton Pleasure Scale over the past week.

CONCLUSIONS

These findings suggest that MDD adolescents exhibited dissociable deficits in reward anticipation and gain or loss feedback that are distinctly modulated by emotional contexts, and they deepen our understanding of the modulation of emotional contexts on the temporal dynamic reorganization of the reward circuit in MDD adolescents.

Preschool-Onset Major Depressive Disorder is Characterized by Electrocortical Deficits in Processing Pleasant Emotional Pictures

Reductions in positive affect are a salient feature of preschool-onset major depressive disorder. Yet, little is known about the psychophysiological correlates of this blunted positive affect and whether reduced physiological responding to pleasant stimuli may differentiate depressed and healthy young children. 120 four-to-seven year old children with current depression and 63 psychiatrically healthy 4-to-7 year old children completed a simple picture-viewing task of pleasant and neutral pictures while event-related potentials (ERPs) were recorded. The early-childhood version of the Kiddie Schedule for Affective Disorders and Depression was used to establish psychiatric diagnoses. A one-way ANCOVA was used to test for group differences in response to pleasant and neutral pictures. Young children with depression showed a reduced response to pleasant vs. neutral pictures (LPP), after controlling for children's age (F(1,180) = 4.15, p = 0.04, η2 = 0.02). The LPP for the children with preschool-onset depression (M = 0.99, SE = 0.65) was significantly smaller than the LPP in the healthy group of young children (M = 3.27, SE = 0.90). This difference did not vary as a function of depression or anhedonia severity within the group with depression or the healthy children. Similar to older children and adolescents with depression, young children with depression display reductions in responsivity to pleasant stimuli as indexed by the LPP. These findings extend prior findings indicating a blunted response to pleasant stimuli in preschool- onset depression. Given the greater neuroplasticity of emotional response and regulation, these findings suggest clinical attention to emotional response to pleasure is an important target in preschool-onset depression. Clinical trial registration information: A Randomized Control Trial of PCIT-ED for Preschool Depression; http://clinicaltrials.gov/;NCT02076425.

Time-Frequency Delta Activity to Social Feedback Demonstrates Differential Associations With Depression and Social Anxiety Symptoms

Social feedback is highly salient and particularly relevant when investigating the pathophysiology of depression and social anxiety. A bourgeoning body of research has demonstrated an association between reward-related delta activity and psychopathology. However, a critical limitation is that these findings are derived from neural responses to monetary feedback, and time-frequency representation of social feedback remains unexplored. In addition, no study has isolated the differential/unique associations of positive valence and the intrinsic rewarding experience of being correct with reward-related neural activity. In the present study, 204 participants underwent electroencephalography (EEG) while they completed a novel paradigm comprised of monetary and social feedback tasks that were matched in trial structure, timing, and feedback stimuli. For each task, participants were instructed to correctly identify one of two doors that would provide positive feedback (monetary win behind the door) or one of two peers who would provide positive feedback (social like); or to correctly identify the door or peer that would provide negative feedback (money loss behind the door/social dislike). A principal component analysis (PCA) was conducted on the time-frequency data and revealed two factors in the delta and one factor in the theta frequency ranges. Results indicated that the lower-frequency delta factor (delta-low) was greater to correct vs. incorrect feedback, more so for social vs. monetary tasks, while the higher-frequency delta factor (delta-high) was greater to correct vs. incorrect feedback for social like, social dislike, and monetary win tasks, but not the monetary loss task. In contrast, the theta factor was greater to incorrect relative to correct feedback in negative valence (lose money/social dislike) but not positive valence (win money/social like) tasks. Furthermore, greater delta-high activity for social feedback was associated with greater social anxiety symptoms, whereas lesser delta-high activity for social feedback was associated with greater depressive symptoms. Finally, greater theta activity to monetary feedback was associated with greater depressive symptoms. The present study provides novel evidence demonstrating unique social vs. monetary feedback-related delta and theta activity, and differential associations between delta activity with depression and social anxiety symptoms. These findings highlight the importance of investigating feedback-related neural responses in the social domain.

Neurophysiological activity following rewards and losses among female adolescents and young adults with borderline personality disorder

Borderline personality disorder (BPD) is a complex and debilitating psychiatric illness. Prior research in adults has shown that neurophysiological deficits in feedback processing and learning from rewards may be central to the development of BPD; however, little research has examined these markers in adolescents and young adults with BPD. The present study used event-related potentials and time-frequency decomposition analysis to probe neural responses to wins and losses in a guessing task among 68 females (13 to 23 years old) either with BPD (n = 35) or no history of mental disorders (healthy control [HC]; n = 33). Participants completed a guessing task wherein they won and lost money at equal frequencies while electroencephalogram (EEG) data were acquired. Adolescents and young adults with BPD showed a smaller differentiation between wins and losses in the reward positivity (RewP) relative to HCs. Using time-frequency decomposition, we isolated distinct frequency bands sensitive to wins (delta = < 3Hz) and losses (theta = 4 Hz to 7 Hz). Compared with BPD participants, HCs showed significantly larger delta power to wins, specifically. The groups did not differ in delta power to losses, nor theta power to wins or losses. Collectively, findings implicate altered reward processing in the pathophysiology of BPD and may inform early identification and targeted intervention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neural Response to Pleasant Pictures Moderates Prospective Relationship Between Stress and Depressive Symptoms in Adolescent Girls

Adolescent girls are at increased risk for depression, which is thought to result from the interaction of biological vulnerabilities and life stressors common to adolescent girls. A blunted late positive potential (LPP) to emotional stimuli (i.e., pleasant and unpleasant) has been associated with depressive symptoms and risk. The current study of adolescent girls examines the moderating effects of the LPP, a candidate biomarker of depression, of the link between life stress and increases in depressive symptoms over 1 year. We measured LPP to pleasant and unpleasant pictures from the International Affective Picture Set among 143 predominantly Caucasian adolescent girls ages 8 to 14, who also reported on the frequency of common life stressors. Self-reported depressive symptoms were assessed both at baseline and 1 year after the initial lab visit. The LPP to pleasant pictures moderated the relationship between baseline life stressors and the change in depressive symptoms. Specifically, life stress was associated with increases in depressive symptoms when the LPP to pleasant pictures was blunted, whereas life stress was associated with decreases in depressive symptoms when the LPP to pleasant pictures was potentiated. These effects showed some specificity to family and school-related stressors and to anhedonic and efficacy-related depressive symptoms. A similar pattern, though not statistically significant, was found for the LPP to unpleasant pictures. Together, these findings suggest that the LPP to pleasant pictures may represent a useful biomarker in identifying individuals at greatest risk of experiencing depressive symptoms following stress.

Cognitive versus behavioral skills in CBT for depressed adolescents: Disaggregating within-patient versus between-patient effects on symptom change

OBJECTIVE

Despite a growing body of research supporting the efficacy of cognitive-behavioral therapy (CBT) for depressed adolescents, few studies have investigated the role of the acquisition and use of CBT skills in accounting for symptom improvement. The present study examined the role of cognitive versus behavioral skills in predicting symptom improvement in depressed youth. Analyses considered different raters of patient skills (patient vs. therapist) as well as disaggregated between-patient versus within-patient effects.

METHOD

Data were derived from a 12-week clinical trial of CBT for depressed adolescent females (N = 33; ages 13-18 years; 69.7% White). Both therapist-report and patient-report measures of CBT skills (skills of cognitive therapy) were acquired at 5 time points throughout therapy: Sessions 1, 3, 6, 9, and 12. Depressive symptoms (Beck Depression Inventory-II) were assessed at every session.

RESULTS

Therapist and patient ratings of CBT skills showed small to moderate associations (rs = .20-.38). Intraclass correlation coefficients indicated that the majority of the variance in skills scores (61-90%) was attributable to within-patient variance from session to session, rather than due to between-patient differences. When disaggregating within-patient and between-patient effects, and consistent with a causal relationship, within-patient variability in both patient-rated (b = -2.55; p = .025) and therapist-rated (b = -2.41; p = .033) behavioral skills predicted subsequent symptom change.

CONCLUSIONS

Analyses highlight the importance of the acquisition and use of behavioral skills in CBT for depressed adolescents. Findings also underscore the importance of disentangling within-patient from between-patient effects in future studies, an approach infrequently used in process-outcome research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neural Indicators of Anhedonia: Predictors and Mechanisms of Treatment Change in a Randomized Clinical Trial in Early Childhood Depression

BACKGROUND

Early childhood depression is associated with anhedonia and reduced event-related potential (ERP) responses to rewarding or pleasant stimuli. Whether these neural measures are indicators of target engagement or treatment outcome is not yet known.

METHODS

We measured ERP responses to win and loss feedback in a guessing task and to pleasant versus neutral pictures in young (4.0-6.9 years of age) depressed children before and after randomization to either 18 weeks of Parent-Child Interaction Therapy-Emotion Development (PCIT-ED) treatment or waitlist (WL) control condition.

RESULTS

Analyses included reward positivity (RewP) data from 118 children randomized to PCIT-ED treatment (n = 60) or WL control condition (n = 58) at baseline and late positive potential (LPP) data from 99 children (44 PCIT-ED treatment vs. 55 WL control condition) at baseline. Children in the PCIT-ED group showed a greater reduction in anhedonia (F1,103 = 10.32, p = .002, partial η2 = .09). RewP reward responses increased more (F1,87 = 5.45, p = .02, partial η2 = .06) for PCIT-ED and a greater change in RewP was associated with a greater reduction in major depressive disorder symptoms (r = -.24, p = .05). Baseline RewP did not predict treatment change. LPPs to positive pictures did not change across treatment, but greater baseline LPPs to positive pictures predicted a higher likelihood of remission from major depressive disorder in the PCIT-ED group (B = 0.14; SE = 0.07; odds ratio = 1.15; p = .03).

CONCLUSIONS

The ERP reward response improved in young children with depression during a treatment designed to enhance emotion development, providing evidence of target engagement of the neural systems associated with reward. Further, greater baseline LPP responses to positive pictures were associated with a greater reduction in depression, suggesting that this ERP measure can predict which children are most likely to respond to treatment.

Reward processing and future life stress: Stress generation pathway to depression

Blunted reward sensitivity and life stress are each depressogenic. Additionally, individuals with clinical and psychosocial vulnerabilities are prone to experience or evoke dependent life stressors (e.g., interpersonal conflict) that, in turn, increase depression risk. However, no previous study has investigated the role of neural vulnerability factors in generating life stress. Therefore, the current study investigated whether a neural measure of reward sensitivity prospectively predicts the generation of life stress, which in turn mediates effects of these neural processes on subsequent depression. Participants were 467 never-depressed adolescent girls. Using event-related potentials, neural sensitivity to the difference between monetary reward and loss (the Reward Positivity [RewP]) was assessed at baseline. Negative life events were assessed twice via interview over the ensuing 18 months, yielding an index of total life stress over the follow-up period. A self-report dimensional measure of depression symptoms was administered at baseline and follow-up. After accounting for baseline age, depression, and race, a blunted RewP predicted greater dependent, but not independent, life stress over the follow-up. Mediation analyses revealed a significant indirect effect of the RewP on follow-up depression through dependent, but not independent, life stress. Our results suggest that neural processing reward and loss plays a crucial role in depressogenic stress generation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Reward Processing in Adolescent Depression Across Neuroimaging Modalities

Depressive symptoms have long been associated with abnormalities in neural processing of reward. However, no review has yet consolidated evidence of such deficits in adolescent depression, integrating findings across neuroimaging modalities, such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). The current review found consistent evidence of reduced striatal responses in anticipation and upon receipt of rewards, and blunted feedback-related negativity (FRN) potentials associated with depression in adolescence, consistent with the adult literature. Furthermore, while these occurred in currently depressed adolescents, they were also found to be predictive of the onset of depressive symptoms in longitudinal studies with community-based adolescent samples. This paper makes recommendations for future work to continue to elucidate this relationship, a greater understanding of which may lead to more targeted and efficacious treatments for depression in adolescence.

Altered reward processing following an acute social stressor in adolescents

Altered reward processing is a transdiagnostic factor implicated in a wide range of psychiatric disorders. While prior animal and adult research has shown that stress contributes to reward dysfunction, less is known about how stress impacts reward processing in youth. Towards addressing this gap, the present study probed neural activation associated with reward processing following an acute stressor. Healthy adolescents (n = 40) completed a clinical assessment, and fMRI data were acquired while participants completed a monetary guessing task under a no-stress condition and then under a stress condition. Based on prior literature, analyses focused on a priori defined regions-of-interest, specifically the striatum (win trials) and dorsal anterior cingulate cortex [dACC] and insula (loss trials). Two main findings emerged. First, reward-related neural activation (i.e., striatum) was blunted in the stress relative to the no-stress condition. Second, the stress condition also contributed to blunted neural response following reward in loss-related regions (i.e., dACC, anterior insula); however, there were no changes in loss sensitivity. These results highlight the importance of conceptualizing neural vulnerability within the presence of stress, as this may clarify risk for mental disorders during a critical period of development.