Reward Processing in Depression: A Conceptual and Meta-Analytic Review Across fMRI and EEG Studies

Association of anhedonia with brain-derived neurotrophic factor and interleukin-10 in major depressive disorder

BACKGROUND

Anhedonia, a core symptom of major depressive disorder (MDD), manifests in two forms: anticipatory and consummatory, reflecting a diminished capacity to anticipate or enjoy pleasurable activities. Prior studies suggest that brain-derived neurotrophic factor (BDNF) and interleukin-10 (IL-10) may play key roles in the emergence of anhedonia in MDD. The specific relationships between these biomarkers and the two forms of anhedonia remain unclear. This study investigated the potential links between BDNF, IL-10, and both forms of anhedonia in MDD patients.

METHODS

This study included 43 participants diagnosed with MDD and 58 healthy controls. It involved detailed assessments of depression and anxiety levels, anticipatory and consummatory pleasure, cognitive functions, and a broad spectrum of plasma biomarkers, such as C-reactive protein, various interleukins, and BDNF. Using partial correlation, variables related to pleasant experiences were identified. Stepwise multiple linear regression analysis was applied to pinpoint the independent predictors of anhedonia in the MDD group.

RESULTS

Demographically, both groups were comparable in terms of age, sex, body mass index, educational year, and marital status. Individuals with MDD displayed markedly reduced levels of anticipatory and consummatory pleasure, higher anxiety, and depression scores compared to healthy controls. Additionally, cognitive performance was notably poorer in the MDD group. These patients also had lower plasma diamine oxidase levels. Analysis linked anhedonia to impaired delayed memory. Regression results identified IL-10 and BDNF as independent predictors of anticipatory and consummatory anhedonia, respectively.

CONCLUSION

These findings demonstrate that anticipatory and consummatory anhedonia are influenced by independent factors, thereby providing critical insights into the distinct neuroimmunological mechanisms that underlie various forms of anhedonia. Clinicl Trial Registration Number: NCT03790085.

Cross-species analysis uncovers the mitochondrial stress response in the hippocampus as a shared mechanism in mouse early life stress and human depression

Depression, or major depressive disorder, poses a significant burden for both individuals and society, affecting approximately 10.8% of the general population. This psychiatric disorder leads to approximately 800,000 deaths per year. A combination of genetic and environmental factors such as early life stress (ELS) increase the risk for development of depression in humans, and a clear role for the hippocampus in the pathophysiology of depression has been shown. Nevertheless, the underlying mechanisms of depression remain poorly understood, resulting in a lack of effective treatments. To better understand the core mechanisms underlying the development of depression, we used a cross-species design to investigate shared hippocampal pathophysiological mechanisms in mouse ELS and human depression. Mice were subjected to ELS by a maternal separation paradigm, followed by RNA sequencing analysis of the adult hippocampal tissue. This identified persistent transcriptional changes linked to mitochondrial stress response pathways, with oxidative phosphorylation and protein folding emerging as the main mechanisms affected by maternal separation. Remarkably, there was a significant overlap between the pathways involved in mitochondrial stress response we observed and publicly available RNAseq data from hippocampal tissue of depressive patients. This cross-species conservation of changes in gene expression of mitochondria-related genes suggests that mitochondrial stress may play a pivotal role in the development of depression. Our findings highlight the potential significance of the hippocampal mitochondrial stress response as a core mechanism underlying the development of depression. Further experimental investigations are required to expand our understanding of these mechanisms.

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

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

The computational structure of consummatory anhedonia

Anhedonia is a reduction in enjoyment, motivation, or interest. It is common across mental health disorders and a harbinger of poor treatment outcomes. The enjoyment aspect, termed 'consummatory anhedonia', in particular poses fundamental questions about how the brain constructs rewards: what processes determine how intensely a reward is experienced? Here, we outline limitations of existing computational conceptualisations of consummatory anhedonia. We then suggest a richer reinforcement learning (RL) account of consummatory anhedonia with a reconceptualisation of subjective hedonic experience in terms of goal progress. This accounts qualitatively for the impact of stress, dysfunctional cognitions, and maladaptive beliefs on hedonic experience. The model also offers new views on the treatments for anhedonia.

Pathways to adolescent social anxiety: Testing interactions between neural social reward function and perceived social threat in daily life

Recent theories suggest that for youth highly sensitive to incentives, perceiving more social threat may contribute to social anxiety (SA) symptoms. In 129 girls (ages 11-13) oversampled for shy/fearful temperament, we thus examined how interactions between neural responses to social reward (vs. neutral) cues (measured during anticipation of peer feedback) and perceived social threat in daily peer interactions (measured using ecological momentary assessment) predict SA symptoms two years later. No significant interactions emerged when neural reward function was modeled as a latent factor. Secondary analyses showed that higher perceived social threat was associated with more severe SA symptoms two years later only for girls with higher basolateral amygdala (BLA) activation to social reward cues at baseline. Interaction effects were specific to BLA activation to social reward (not threat) cues, though a main effect of BLA activation to social threat (vs. neutral) cues on SA emerged. Unexpectedly, interactions between social threat and BLA activation to social reward cues also predicted generalized anxiety and depression symptoms two years later, suggesting possible transdiagnostic risk pathways. Perceiving high social threat may be particularly detrimental for youth highly sensitive to reward incentives, potentially due to mediating reward learning processes, though this remains to be tested.

Common neural deficits across reward functions in major depression: a meta-analysis of fMRI studies

Major depressive disorder (MDD) is characterized by deficient reward functions in the brain. However, existing findings on functional alterations during reward anticipation, reward processing, and learning among MDD patients are inconsistent, and it was unclear whether a common reward system implicated in multiple reward functions is altered in MDD. Here we meta-analyzed 18 past studies that compared brain reward functions between adult MDD patients (N = 477, mean age = 26.50 years, female = 59.40%) and healthy controls (N = 506, mean age = 28.11 years, females = 55.58%), and particularly examined group differences across multiple reward functions. Jack-knife sensitivity and subgroup meta-analyses were conducted to test robustness of findings across patient comorbidity, task paradigm, and reward nature. Meta-regression analyses assessed the moderating effect of patient symptom severity and anhedonia scores. We found during reward anticipation, MDD patients showed lower activities in the lateral prefrontal-thalamus circuitry. During reward processing, patients displayed reduced activities in the right striatum and prefrontal cortex, but increased activities in the left temporal cortex. During reward learning, patients showed reduced activity in the lateral prefrontal-thalamic-striatal circuitry and the right parahippocampal-occipital circuitry but higher activities in bilateral cerebellum and the left visual cortex. MDD patients showed decreased activity in the right thalamus during both reward anticipation and learning, and in the right caudate during both reward processing and learning. Larger functional changes in MDD were observed among patients with more severe symptoms and higher anhedonia levels. The thalamic-striatal circuitry functional alterations could be the key neural mechanism underlying MDD patients overarching reward function deficiencies.

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

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

The Predictive Potential of Heart Rate Variability for Depression

Heart rate variability (HRV),a measure of the fluctuations in the intervals between consecutive heartbeats, is an indicator of changes in the autonomic nervous system. A chronic reduction in HRV has been repeatedly linked to clinical depression. However, the chronological and mechanistic aspects of this relationship, between the neural, physiological, and psychopathological levels, remain unclear. In this review we present evidence by which changes in HRV might precede the onset of depression. We describe several pathways that can facilitate this relationship. First, we examine a theoretical model of the impact of autonomic imbalance on HRV and its role in contributing to mood dysregulation and depression. We then highlight brain regions that are regulating both HRV and emotion, suggesting these neural regions, and the Insula in particular, as potential mediators of this relationship. We also present additional possible mediating mechanisms involving the immune system and inflammation processes. Lastly, we support this model by showing evidence that modification of HRV with biofeedback leads to an improvement in some symptoms of depression. The possibility that changes in HRV precede the onset of depression is critical to put to the test, not only because it could provide insights into the mechanisms of the illness but also because it may offer a predictive anddiagnosticphysiological marker for depression. Importantly, it could also help to develop new effective clinical interventions for treating depression.

Attention modulates facial expression processing in subsyndromal depression: A behavioral and ERP study

Impaired facial expression perception is a core element in depression, but the underlying mechanism remains controversial. This event-related potential study investigated how attention modulates facial expression perception in depression using a nonclinical sample. A group of healthy controls (HC, N = 39) and a group of individuals with subsyndromal depression (SD, N = 39) categorized faces based on either facial expression (happy vs. sad) or gender (male vs. female). Behaviorally, the SD group was less sensitive to the emotional valence of facial expression than the HC group when their attention was directed to facial expression, as revealed by comparable subjective ratings and accuracy rates in response to facial expressions. When attention was directed towards facial gender, the SD group versus the HC group showed a negative bias, as revealed by a faster N170 for sad faces than happy faces. Together, our findings suggest that attention plays a role in understanding the relationship between depression and facial expression perception.

The Impact of Problematic Smartphone Use on Sleep Quality Among Chinese Young Adults: Investigating Anxiety and Depression as Mediators in a Three-Wave Longitudinal Study

Background

Sleep disorders are a significant health issue that urgently needs to be addressed among undergraduate students, and one of the potential underlying problems could be problematic smartphone use (PSU). This study aimed to clarify the relationship between PSU and poor sleep quality by investigating the independent and serial mediating roles of anxiety and depressive symptoms in a population of university students in Tibet, China.

Methods

A total of 2993 Tibetan college students completed three waves of data surveys, with all participants completing questionnaires on PSU, anxiety, depressive symptoms, and sleep quality (Time 1 (T1) -Time 3 (T3)). Bootstrapped mediation analysis was used to explore the mediating role of anxiety and depressive symptoms in the longitudinal relationship between PSU and sleep quality.

Results

Both direct and indirect effects of PSU on poor sleep quality were found. PSU (T1) can had not only a direct negative influence on poor sleep quality (T3) among young adults (direct effect = 0.021, 95% CI = 0.010-0.033) but also an indirect negative impact via three pathways: the independent mediating effect of anxiety symptoms (T2) (indirect effect 1 = 0.003, 95% CI = 0.001-0.006), the independent mediating effect of depressive symptoms (T2) (indirect effect 2 = 0.004, 95% CI = 0.002-0.006), and the serial mediating effects of anxiety (T2) and depressive symptoms (T2) (indirect effect 3 = 0.008, 95% CI=0.005-0.011).

Conclusion

These findings highlight the role of anxiety and depression symptoms as joint mediating factors in the relationship between PSU and sleep disturbances. Interventions focused on improving sleep that incorporate behavioural measures could benefit from treatment approaches targeting mental disorders.

Annual Research Review: Neuroimmune network model of depression: a developmental perspective

Depression is a serious public health problem, and adolescence is an 'age of risk' for the onset of Major Depressive Disorder. Recently, we and others have proposed neuroimmune network models that highlight bidirectional communication between the brain and the immune system in both mental and physical health, including depression. These models draw on research indicating that the cellular actors (particularly monocytes) and signaling molecules (particularly cytokines) that orchestrate inflammation in the periphery can directly modulate the structure and function of the brain. In the brain, inflammatory activity heightens sensitivity to threats in the cortico-amygdala circuit, lowers sensitivity to rewards in the cortico-striatal circuit, and alters executive control and emotion regulation in the prefrontal cortex. When dysregulated, and particularly under conditions of chronic stress, inflammation can generate feelings of dysphoria, distress, and anhedonia. This is proposed to initiate unhealthy, self-medicating behaviors (e.g. substance use, poor diet) to manage the dysphoria, which further heighten inflammation. Over time, dysregulation in these brain circuits and the inflammatory response may compound each other to form a positive feedback loop, whereby dysregulation in one organ system exacerbates the other. We and others suggest that this neuroimmune dysregulation is a dynamic joint vulnerability for depression, particularly during adolescence. We have three goals for the present paper. First, we extend neuroimmune network models of mental and physical health to generate a developmental framework of risk for the onset of depression during adolescence. Second, we examine how a neuroimmune network perspective can help explain the high rates of comorbidity between depression and other psychiatric disorders across development, and multimorbidity between depression and stress-related medical illnesses. Finally, we consider how identifying neuroimmune pathways to depression can facilitate a 'next generation' of behavioral and biological interventions that target neuroimmune signaling to treat, and ideally prevent, depression in youth and adolescents.

Annual Research Review: Puberty and the development of anhedonia - considering childhood adversity and inflammation

Anhedonia, or diminished pleasure and motivation, is a symptom of severe mental illness (e.g., depressive disorder, bipolar disorder, schizophrenia) that emerges during adolescence. Anhedonia is a pernicious symptom that is related to social impairments, treatment resistance, and suicide. As the mechanisms of anhedonia are postulated to include the frontostriatal circuitry and the dopamine neuromodulatory system, the development and plasticity of these systems during the vulnerable period of adolescence, as well as their sensitivity to pubertal hormones, suggest that pubertal maturation could play a role in the development of anhedonia. This review takes a developmental perspective, considering the possibility that anhedonia emerges in the context of pubertal maturation and adolescent development, with childhood adversity and chronic inflammation influencing neural reward systems to accelerate anhedonia's progression. Here, we review the relevant extant literature on the components of this model and suggest directions for future research.

How are irritability and anhedonia symptoms linked? A network approach

BACKGROUND

Anhedonia and irritability are two prevalent symptoms of major depressive disorder (MDD) that predict greater depression severity and poor outcomes, including suicidality. Although both symptoms have been proposed to result from paradoxical reward processing dysfunctions, the interactions between these symptoms remain unclear. Anhedonia is a multifaceted symptom reflecting impairments in multiple dimensions of reward processing (e.g., pleasure, desire, motivation, and effort) across distinct reward types (e.g., food, sensory experiences, social activities, hobbies) that may differentially interact with irritability. This study investigated the complex associations between anhedonia and irritability using network analysis.

METHOD

Participants (N = 448, Mage = 33.29, SD = 14.58) reported their symptoms of irritability on the Brief Irritability Test (Holtzman et al., 2015) and anhedonia (i.e., pleasure, desire, motivation, and effort dimensions across four reward types) on the Dimensional Anhedonia Rating Scale (Rizvi et al., 2015). A regularized Gaussian Graphical Model was built to estimate the network structure between items.

RESULTS

Irritability was negatively related to willingness to expand effort to obtain food/drinks (estimate = -0.18), social activities (-0.13), and hobbies (-0.12) rewards. Irritability was positively associated with a desire for food/drinks (0.12).

LIMITATIONS

Only a small proportion (5.8%) of our sample was clinical and the study design was cross-sectional.

CONCLUSION

A specific link between irritability and the effort dimension of the hedonic response across three reward types was identified. Investigating effort expenditure deficits with experimental paradigms may help us understand the mechanisms underlying the comorbidity between irritability and anhedonia in the context of MDD.

Characterizing major depressive disorder and substance use disorder using heatmaps and variable interactions: The utility of operant behavior and brain structure relationships

BACKGROUND

Rates of depression and addiction have risen drastically over the past decade, but the lack of integrative techniques remains a barrier to accurate diagnoses of these mental illnesses. Changes in reward/aversion behavior and corresponding brain structures have been identified in those with major depressive disorder (MDD) and cocaine-dependence polysubstance abuse disorder (CD). Assessment of statistical interactions between computational behavior and brain structure may quantitatively segregate MDD and CD.

METHODS

Here, 111 participants [40 controls (CTRL), 25 MDD, 46 CD] underwent structural brain MRI and completed an operant keypress task to produce computational judgment metrics. Three analyses were performed: (1) linear regression to evaluate groupwise (CTRL v. MDD v. CD) differences in structure-behavior associations, (2) qualitative and quantitative heatmap assessment of structure-behavior association patterns, and (3) the k-nearest neighbor machine learning approach using brain structure and keypress variable inputs to discriminate groups.

RESULTS

This study yielded three primary findings. First, CTRL, MDD, and CD participants had distinct structure-behavior linear relationships, with only 7.8% of associations overlapping between any two groups. Second, the three groups had statistically distinct slopes and qualitatively distinct association patterns. Third, a machine learning approach could discriminate between CTRL and CD, but not MDD participants.

CONCLUSIONS

These findings demonstrate that variable interactions between computational behavior and brain structure, and the patterns of these interactions, segregate MDD and CD. This work raises the hypothesis that analysis of interactions between operant tasks and structural neuroimaging might aide in the objective classification of MDD, CD and other mental health conditions.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Amplification of Positivity Treatment for Anxiety and Depression: A Randomized Experimental Therapeutics Trial Targeting Social Reward Sensitivity to Enhance Social Connectedness

BACKGROUND

Social disconnection is common and causes significant impairment in anxiety and depressive disorders, and it does not respond sufficiently to available treatments. The positive valence system supports social bond formation and maintenance but is often hyporesponsive in people with anxiety or depression. We conducted an experimental therapeutics trial to test the hypothesis that targeting positive valence processes through cognitive and behavioral strategies would enhance responsivity to social rewards, a core mechanism underlying social connectedness.

METHODS

Sixty-eight adults who endorsed clinically elevated anxiety and/or depression with social impairment were randomized 1:1:1 to 5 (n = 23) or 10 (n = 22) sessions of amplification of positivity (AMP) treatment or waitlist (n = 23). Pre- to posttreatment change in striatal activity (primary outcome) during social reward anticipation was measured using functional magnetic resonance imaging, and reactivity to a social affiliation task (secondary) and self-reported social connectedness (exploratory) were examined. Primary analyses compared AMP (doses combined) versus waitlist. A second aim was to compare the effects of different doses.

RESULTS

AMP engaged the hypothesized treatment target, leading to greater striatal activation during anticipation of social rewards versus waitlist (d = 1.01 [95% CI = 0.42-1.61]; largest striatal volume). AMP yielded larger improvements in positive affect and approach behavior during the affiliation task (but not other outcomes) and social connectedness. Larger striatal and social connectedness increases were observed for 5-session versus 10-session AMP (d range = 0.08-1.03).

CONCLUSIONS

Teaching people with anxiety or depression strategies to increase positive thoughts, behaviors, and emotions enhances activity in brain regions that govern social reward processing and promotes social connectedness. Social reward sensitivity may be a transdiagnostic target for remediating social disconnection.

Abnormal caudate nucleus activity in patients with depressive disorder: Meta-analysis of task-based functional magnetic resonance imaging studies with behavioral domain

During task-based functional magnetic resonance imaging (t-fMRI) patients with depressive disorder (DD) have shown abnormal caudate nucleus activation. There have been no meta-analyses that are conducted on the caudate nucleus using Activation Likelihood Estimation (ALE) in patients with DD, and the relationships between abnormal caudate activity and different behavior domains in patients with DD remain unclear. There were 24 previously published t-fMRI studies included in the study with the caudate nucleus as the region of interest. Meta-analyses were performed using the method of ALE. Included five ALE meta-analyses: (1) the hypoactivated caudate nucleus relative to healthy controls (HCs); (2) the hyper-activated caudate nucleus; (3) the abnormal activation in the caudate nucleus in the emotion domain; (4) the abnormal activation in cognition domain; (5) the abnormal activation in the affective cognition domain. Results revealed that the hypo-/hyper-activity in the caudate subregions is mainly located in the caudate body and head, while the relationships between abnormal caudate subregions and different behavior domains are complex. The hypoactivation of the caudate body and head plays a key role in the emotions which indicates there is a positive relationship between the decreased caudate activity and depressed emotional behaviors in patients with DD.

Distinct neurofunctional alterations during motivational and hedonic processing of natural and monetary rewards in depression - a neuroimaging meta-analysis

Reward processing dysfunctions are considered a candidate mechanism underlying anhedonia and apathy in depression. Neuroimaging studies have documented that neurofunctional alterations in mesocorticolimbic circuits may neurally mediate these dysfunctions. However, common and distinct neurofunctional alterations during motivational and hedonic evaluation of monetary and natural rewards in depression have not been systematically examined. Here, we capitalized on pre-registered neuroimaging meta-analyses to (1) establish general reward-related neural alterations in depression, (2) determine common and distinct alterations during the receipt and anticipation of monetary v. natural rewards, and, (3) characterize the differences on the behavioral, network, and molecular level. The pre-registered meta-analysis (https://osf.io/ay3r9) included 633 depressed patients and 644 healthy controls and revealed generally decreased subgenual anterior cingulate cortex and striatal reactivity toward rewards in depression. Subsequent comparative analyses indicated that monetary rewards led to decreased hedonic reactivity in the right ventral caudate while natural rewards led to decreased reactivity in the bilateral putamen in depressed individuals. These regions exhibited distinguishable profiles on the behavioral, network, and molecular level. Further analyses demonstrated that the right thalamus and left putamen showed decreased activation during the anticipation of monetary reward. The present results indicate that distinguishable neurofunctional alterations may neurally mediate reward-processing alterations in depression, in particular, with respect to monetary and natural rewards. Given that natural rewards prevail in everyday life, our findings suggest that reward-type specific interventions are warranted and challenge the generalizability of experimental tasks employing monetary incentives to capture reward dysregulations in everyday life.

Anhedonia in adolescents at transdiagnostic familial risk for severe mental illness: Clustering by symptoms and mechanisms of association with behavior

BACKGROUND

Anhedonia is a transdiagnostic symptom of severe mental illness (SMI) and emerges during adolescence. Possible subphenotypes and neural mechanisms of anhedonia in adolescents at risk for SMI are understudied.

METHODS

Adolescents at familial risk for SMI (N = 81) completed anhedonia (e.g., consummatory, anticipatory, social), demographic, and clinical measures and one year prior, a subsample (N = 46) completed fMRI scanning during a monetary reward task. Profiles were identified using k-means clustering of anhedonia type and differences in demographics, suicidal ideation, impulsivity, and emotional processes were examined. Moderation analyses were conducted to investigate whether levels of brain activation of reward regions moderated the relationships between anhedonia type and behaviors.

RESULTS

Two-clusters emerged: a high anhedonia profile (high-anhedonia), characterized by high levels of all types of anhedonia, (N = 32) and a low anhedonia profile (low-anhedonia), characterized by low levels of anhedonia types (N = 49). Adolescents in the high-anhedonia profile reported more suicidal ideation and negative affect, and less positive affect and desire for emotional closeness than low-anhedonia profile. Furthermore, more suicidal ideation, less positive affect, and less desire for emotional closeness differentiated the familial high-risk, high-anhedonia profile adolescents from the familial high-risk, low-anhedonia profile adolescents. Across anhedonia profiles, moderation analyses revealed that adolescents with high dmPFC neural activation in response to reward had positive relationships between social, anticipatory, and consummatory anhedonia and suicidal ideation.

LIMITATIONS

Small subsample with fMRI data.

CONCLUSION

Profiles of anhedonia emerge transdiagnostically and vary on clinical features. Anhedonia severity and activation in frontostriatal reward areas have value for clinically important outcomes such as suicidal ideation.

Bayesian evaluation of diverging theories of episodic and affective memory distortions in dysphoria

People suffering from dysphoria retrieve autobiographical memories distorted in content and affect, which may contribute to the aetiology and maintenance of depression. However, key memory difficulties in dysphoria remain elusive because theories disagree how memories of different valence are altered. Here, we assessed the psychophysiological expression of affect and retrieved episodic detail while participants with dysphoria (but without a diagnosed mental illness) and participants without dysphoria relived positive, negative, and neutral memories. We show that participants with dysphoria retrieve positive memories with diminished episodic detail and negative memories with enhanced detail, compared to participants without dysphoria. This is in line with negativity bias but not overgeneral memory bias theories. According to confirmatory analyses, participants with dysphoria also express diminished positive affect and enhanced negative affect when retrieving happy memories, but exploratory analyses suggest that this increase in negative affect may not be robust. Further confirmatory analyses showed that affective responses to memories are not related to episodic detail and already present during the experience of new emotional events. Our results indicate that affective memory distortions may not emerge from mnemonic processes but from general distortions in positive affect, which challenges assumptions of memory theories and therapeutics. Protocol registration: The Stage 1 protocol for this Registered Report was accepted in principle on the 18rd of March 2021. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.14605374.v1 .

Diagnosing and tracking depression based on eye movement in response to virtual reality

Introduction

Depression is a prevalent mental illness that is primarily diagnosed using psychological and behavioral assessments. However, these assessments lack objective and quantitative indices, making rapid and objective detection challenging. In this study, we propose a novel method for depression detection based on eye movement data captured in response to virtual reality (VR).

Methods

Eye movement data was collected and used to establish high-performance classification and prediction models. Four machine learning algorithms, namely eXtreme Gradient Boosting (XGBoost), multilayer perceptron (MLP), Support Vector Machine (SVM), and Random Forest, were employed. The models were evaluated using five-fold cross-validation, and performance metrics including accuracy, precision, recall, area under the curve (AUC), and F1-score were assessed. The predicted error for the Patient Health Questionnaire-9 (PHQ-9) score was also determined.

Results

The XGBoost model achieved a mean accuracy of 76%, precision of 94%, recall of 73%, and AUC of 82%, with an F1-score of 78%. The MLP model achieved a classification accuracy of 86%, precision of 96%, recall of 91%, and AUC of 86%, with an F1-score of 92%. The predicted error for the PHQ-9 score ranged from -0.6 to 0.6.To investigate the role of computerized cognitive behavioral therapy (CCBT) in treating depression, participants were divided into intervention and control groups. The intervention group received CCBT, while the control group received no treatment. After five CCBT sessions, significant changes were observed in the eye movement indices of fixation and saccade, as well as in the PHQ-9 scores. These two indices played significant roles in the predictive model, indicating their potential as biomarkers for detecting depression symptoms.

Discussion

The results suggest that eye movement indices obtained using a VR eye tracker can serve as useful biomarkers for detecting depression symptoms. Specifically, the fixation and saccade indices showed promise in predicting depression. Furthermore, CCBT demonstrated effectiveness in treating depression, as evidenced by the observed changes in eye movement indices and PHQ-9 scores. In conclusion, this study presents a novel approach for depression detection using eye movement data captured in VR. The findings highlight the potential of eye movement indices as biomarkers and underscore the effectiveness of CCBT in treating depression.

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

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

Sticky criticism? Affective and neural responses to parental criticism and praise in adolescents with depression

BACKGROUND

Parent-adolescent interactions, particularly parental criticism and praise, have previously been identified as factors relevant to self-concept development and, when negative, to adolescent depression. Yet, whether adolescents with depression show aberrant emotional and neural reactivity to parental criticism and praise is understudied.

METHODS

Adolescents with depression (n = 20) and healthy controls (n = 59) received feedback supposedly provided by their mother or father in the form of negative ('untrustworthy'), neutral ('chaotic'), and positive ('respectful') personality evaluations while in an MRI-scanner. After each feedback word, adolescents reported their mood. Beforehand, adolescents had rated whether these personality evaluations matched their self-views.

RESULTS

In both groups, mood decreased after criticism and increased after praise. Adolescents with depression reported blunted mood responses after praise, whereas there were no mood differences after criticism. Neuroimaging analyses revealed that adolescents with depression (v. healthy controls) exhibited increased activity in response to criticism in the subgenual anterior cingulate cortex, temporal pole, hippocampus, and parahippocampal gyrus. Praise consistent with adolescents' self-views improved mood independent of depression status, while criticism matching self-views resulted in smaller mood increases in adolescents with depression (v. healthy controls). Exploratory analyses indicated that adolescents with depression recalled criticism (v. praise) more.

CONCLUSIONS

Adolescents with depression might be especially attentive to parental criticism, as indexed by increased sgACC and hippocampus activity, and memorize this criticism more. Together with lower positive impact of praise, these findings suggest that cognitive biases in adolescent depression may affect how parental feedback is processed, and may be fed into their self-views.

Effectiveness of behavioral activation and mindfulness in increasing reward sensitivity and reducing depressive symptoms - A randomized controlled trial

Reward insensitivity is a potential key mechanism regarding the maintenance of depression. However, there is a lack of research examining and comparing the effectiveness of different psychological interventions in modifying reward insensitivity. This four-arm randomized controlled trial (RCT) investigated a two-week online intervention. After screening for eligibility, a total of 336 participants were randomized, and 224 participated per-protocol. Participants were assigned to either a) behavioral activation, b) mindfulness and gratitude, c) a combination of both, or d) a waitlist control condition. They received videos and implemented daily exercises. Reward sensitivity and depressive symptoms served as primary outcomes. Behavioral activation and mindfulness significantly improved depressive symptoms and reward sensitivity. However, the effects of behavioral activation were not superior. The combination treatment versus the waiting group was insignificant regarding reward insensitivity. Explorative analyses revealed that all intervention groups reduced anhedonia substantially. Our findings imply that brief online interventions with behavioral activation and mindfulness-based approaches can impact reward insensitivity, while effects for a combination were less clear. Nonetheless, our results do not allow us to infer the differential effectiveness of the interventions. There is a clear need for treatments better targeting maintaining factors of depression, such as reward insensitivity. Clinical trial registration number: NCT05402150.

Feedback negativity and feedback-related P3 in individuals at risk for depression: Comparing surface potentials and current source densities

Blunted responses to reward feedback have been linked to major depressive disorder (MDD) and depression risk. Using a monetary incentive delay task (win, loss, break-even), we investigated the impact of family risk for depression and lifetime history of MDD and anxiety disorder with 72-channel electroencephalograms (EEG) recorded from 29 high-risk and 32 low-risk individuals (15-58 years, 30 male). Linked-mastoid surface potentials (ERPs) and their corresponding reference-free current source densities (CSDs) were quantified by temporal principal components analysis (PCA). Each PCA solution revealed a midfrontal feedback negativity (FN; peak around 310 ms) and a posterior feedback-P3 (fb-P3; 380 ms) as two distinct reward processing stages. Unbiased permutation tests and multilevel modeling of component scores revealed greater FN to loss than win and neutral for all stratification groups, confirming FN sensitivity to valence. Likewise, all groups had greater fb-P3 to win and loss than neutral, confirming that fb-P3 indexes motivational salience and allocation of attention. By contrast, group effects were subtle, dependent on data transformation (ERP, CSD), and did not confirm reduced FN or fb-P3 for at-risk individuals. Instead, CSD-based fb-P3 was overall reduced in individuals with than without MDD history, whereas ERP-based fb-P3 was greater for high-risk individuals than for low-risk individuals for monetary, but not neutral outcomes. While the present findings do not support blunted reward processing in depression and depression risk, our side-by-side comparison underscores how the EEG reference choice affects the characterization of subtle group differences, strongly advocating the use of reference-free techniques.

Children's neural reactivity to maternal praise and criticism: Associations with early depressive symptoms and maternal depression

Caregiving experiences are implicated in children's depression risk; however, children's neural reactivity to positive and negative feedback from mothers, a potential mediator of depression risk, is poorly understood. In a sample of 81 children (Mage = 11.12 years, SDage = 0.63), some of whom were recruited based on a maternal history of depression (n = 29), we used fMRI to characterize children's neural responses to maternal praise and criticism. Maternal history of depression was unrelated to children's brain activity during both the praise and criticism conditions; however, ROI analyses showed that children's self-reported depressive symptoms were negatively associated with functional activity in the left anterior insula and right putamen while hearing maternal criticism. Whole-brain analyses showed that children's depressive symptoms were positively associated with left inferior frontal gyrus activity while listening to maternal praise. These findings complement past work implicating these brain regions in the processing of emotionally salient stimuli, reward processing, and internal speech. Given associations between early depressive symptoms and later disorder, findings suggest that maladaptive neural processing of maternal feedback may contribute to children's early emerging risk for depression.

Applications of functional near-infrared spectroscopy in non-drug therapy of traditional Chinese medicine: a review

Non-drug therapies of traditional Chinese medicine (TCM), including acupuncture, massage, tai chi chuan, and Baduanjin, have emerged as widespread interventions for the treatment of various diseases in clinical practice. In recent years, preliminary studies on the mechanisms of non-drug therapies of TCM have been mostly based on functional near-infrared spectroscopy (fNIRS) technology. FNIRS is an innovative, non-invasive tool to monitor hemodynamic changes in the cerebral cortex. Our review included clinical research conducted over the last 10 years, establishing fNIRS as a reliable and stable neuroimaging technique. This review explores new applications of this technology in the field of neuroscience. First, we summarize the working principles of fNIRS. We then present preventive research on the use of fNIRS in healthy individuals and therapeutic research on patients undergoing non-drug therapies of TCM. Finally, we emphasize the potential for encouraging future advancements in fNIRS studies to establish a theoretical framework for research in related fields.

Unraveling the link between childhood maltreatment and depression: Insights from the role of ventral striatum and middle cingulate cortex in hedonic experience and emotion regulation

Childhood maltreatment is an established risk factor for psychopathology. However, it remains unclear how childhood traumatic events relate to mental health problems and how the brain is involved. This study examined the serial mediation effect of brain morphological alterations and emotion-/reward-related functions on linking the relationship from maltreatment to depression. We recruited 156 healthy adolescents and young adults and an additional sample of 31 adolescents with major depressive disorder for assessment of childhood maltreatment, depressive symptoms, cognitive reappraisal and anticipatory/consummatory pleasure. Structural MRI data were acquired to identify maltreatment-related cortical and subcortical morphological differences. The mediation models suggested that emotional maltreatment of abuse and neglect, was respectively associated with increased gray matter volume in the ventral striatum and greater thickness in the middle cingulate cortex. These structural alterations were further related to reduced anticipatory pleasure and disrupted cognitive reappraisal, which contributed to more severe depressive symptoms among healthy individuals. The above mediating effects were not replicated in our clinical group partly due to the small sample size. Preventative interventions can target emotional and reward systems to foster resilience and reduce the likelihood of future psychiatric disorders among individuals with a history of maltreatment.

Transdiagnostic inflexible learning dynamics explain deficits in depression and schizophrenia

Deficits in reward learning are core symptoms across many mental disorders. Recent work suggests that such learning impairments arise by a diminished ability to use reward history to guide behaviour, but the neuro-computational mechanisms through which these impairments emerge remain unclear. Moreover, limited work has taken a transdiagnostic approach to investigate whether the psychological and neural mechanisms that give rise to learning deficits are shared across forms of psychopathology. To provide insight into this issue, we explored probabilistic reward learning in patients diagnosed with major depressive disorder (n = 33) or schizophrenia (n = 24) and 33 matched healthy controls by combining computational modelling and single-trial EEG regression. In our task, participants had to integrate the reward history of a stimulus to decide whether it is worthwhile to gamble on it. Adaptive learning in this task is achieved through dynamic learning rates that are maximal on the first encounters with a given stimulus and decay with increasing stimulus repetitions. Hence, over the course of learning, choice preferences would ideally stabilize and be less susceptible to misleading information. We show evidence of reduced learning dynamics, whereby both patient groups demonstrated hypersensitive learning (i.e. less decaying learning rates), rendering their choices more susceptible to misleading feedback. Moreover, there was a schizophrenia-specific approach bias and a depression-specific heightened sensitivity to disconfirmational feedback (factual losses and counterfactual wins). The inflexible learning in both patient groups was accompanied by altered neural processing, including no tracking of expected values in either patient group. Taken together, our results thus provide evidence that reduced trial-by-trial learning dynamics reflect a convergent deficit across depression and schizophrenia. Moreover, we identified disorder distinct learning deficits.

Reward Functioning in General and Specific Psychopathology in Children and Adults

OBJECTIVE

Problems with reward processing have been implicated in multiple psychiatric disorders, but psychiatric comorbidities are common and their specificity to individual psychopathologies is unknown. Here, we evaluate the association between reward functioning and general or specific psychopathologies.

METHOD

1,213 adults and their1,531 children (ages 6-12) completed various measures of the Positive Valence System domain from the Research Domain Criteria (RDoC). Psychopathology was assessed using the Child Behavior Checklist for children and the Adult Self Report for parents.

RESULTS

One general factor identified via principal factors factor analysis explained most variance in psychopathology in both groups. Measures of reward were associated with the general factor and most specific psychopathologies. Certain reward constructs were associated solely with specific psychopathologies but not general psychopathology. However, some prior associations between reward and psychopathology did not hold following removal of comorbidity.

CONCLUSION

Reward dysfunction is significantly associated with both general and specific psychopathologies.

Altered reward network responses to social touch in major depression

BACKGROUND

Social touch is an integral part of social relationships and has been associated with reward. Major depressive disorder (MDD) is characterized by severe impairments in reward processing, but the neural effects of social touch in MDD are still elusive. In this study, we aimed to determine whether the neural processing of social touch is altered in MDD and to assess the impact of antidepressant therapy.

METHODS

Before and after antidepressant treatment, 53 MDD patients and 41 healthy controls underwent functional magnetic resonance imaging (fMRI) while receiving social touch. We compared neural responses to social touch in the reward network, behavioral ratings of touch comfort and general aversion to interpersonal touch in patients to controls. Additionally, we examined the effect of treatment response on those measures.

RESULTS

Clinical symptoms decreased after treatment and 43.4% of patients were classified as responders. Patients reported higher aversion to interpersonal touch and lower comfort ratings during the fMRI paradigm than controls. Patients showed reduced responses to social touch in the nucleus accumbens, caudate nucleus and putamen than controls, both before and after treatment. Contrary to our hypotheses, these effects were independent of touch velocity. Non-responders exhibited blunted response in the caudate nucleus and the insula compared to responders, again irrespective of time.

CONCLUSIONS

These findings suggest altered striatal processing of social touch in MDD. Persistent dysfunctional processing of social touch despite clinical improvements may constitute a latent risk factor for social withdrawal and isolation.

Trying to name what doesn't change: Neural nonresponse to Cognitive Therapy for depression

BACKGROUND

Theoretical models of neural mechanisms underlying Cognitive Behavior Therapy (CBT) for major depressive disorder (MDD) propose that psychotherapy changes neural functioning of prefrontal cortical structures associated with cognitive-control processes (DeRubeis, Siegle, & Hollon, ); however, MDD is persistent and characterized by long-lasting vulnerabilities to recurrence after intervention, suggesting that underlying neural mechanisms of MDD remain despite treatment. It follows that identification of treatment-resistant aberrant neural processes in MDD may inform clinical and research efforts targeting sustained remission. Thus, we sought to identify brain regions showing aberrant neural functioning in MDD that either (1) fail to exhibit substantive change (nonresponse) or (2) exhibit functional changes (response) following CBT.

METHODS

To identify treatment-resistant neural processes (as well as neural processes exhibiting change after treatment), we collected functional magnetic resonance imaging (fMRI) data of MDD patients (n = 58) before and after CBT as well as never-depressed controls (n = 35) before and after a similar amount of time. We evaluated fMRI data using conjunction analyses, which utilized several contrast-based criteria to characterize brain regions showing both differences between patients and controls at baseline and nonresponse or response to CBT.

RESULTS

Findings revealed nonresponse in a cerebellar region and response in prefrontal and parietal regions.

CONCLUSIONS

Results are consistent with prior theoretical models of CBT's direct effect on cortical regulatory processes but expand on them with identification of additional regions (and associated neural systems) of response and nonresponse to CBT.

Functional magnetic resonance imaging study of group independent components underpinning item responses to paranoid-depressive scale

BACKGROUND

Our study expand upon a large body of evidence in the field of neuropsychiatric imaging with cognitive, affective and behavioral tasks, adapted for the functional magnetic resonance imaging (MRI) (fMRI) experimental environment. There is sufficient evidence that common networks underpin activations in task-based fMRI across different mental disorders.

AIM

To investigate whether there exist specific neural circuits which underpin differential item responses to depressive, paranoid and neutral items (DN) in patients respectively with schizophrenia (SCZ) and major depressive disorder (MDD).

METHODS

60 patients were recruited with SCZ and MDD. All patients have been scanned on 3T magnetic resonance tomography platform with functional MRI paradigm, comprised of block design, including blocks with items from diagnostic paranoid (DP), depression specific (DS) and DN from general interest scale. We performed a two-sample t-test between the two groups-SCZ patients and depressive patients. Our purpose was to observe different brain networks which were activated during a specific condition of the task, respectively DS, DP, DN.

RESULTS

Several significant results are demonstrated in the comparison between SCZ and depressive groups while performing this task. We identified one component that is task-related and independent of condition (shared between all three conditions), composed by regions within the temporal (right superior and middle temporal gyri), frontal (left middle and inferior frontal gyri) and limbic/salience system (right anterior insula). Another component is related to both diagnostic specific conditions (DS and DP) e.g. It is shared between DEP and SCZ, and includes frontal motor/language and parietal areas. One specific component is modulated preferentially by to the DP condition, and is related mainly to prefrontal regions, whereas other two components are significantly modulated with the DS condition and include clusters within the default mode network such as posterior cingulate and precuneus, several occipital areas, including lingual and fusiform gyrus, as well as parahippocampal gyrus. Finally, component 12 appeared to be unique for the neutral condition. In addition, there have been determined circuits across components, which are either common, or distinct in the preferential processing of the sub-scales of the task.

CONCLUSION

This study has delivers further evidence in support of the model of trans-disciplinary cross-validation in psychiatry.

A novel technique for delineating the effect of variation in the learning rate on the neural correlates of reward prediction errors in model-based fMRI

Introduction

Computational models play an increasingly important role in describing variation in neural activation in human neuroimaging experiments, including evaluating individual differences in the context of psychiatric neuroimaging. In particular, reinforcement learning (RL) techniques have been widely adopted to examine neural responses to reward prediction errors and stimulus or action values, and how these might vary as a function of clinical status. However, there is a lack of consensus around the importance of the precision of free parameter estimation for these methods, particularly with regard to the learning rate. In the present study, I introduce a novel technique which may be used within a general linear model (GLM) to model the effect of mis-estimation of the learning rate on reward prediction error (RPE)-related neural responses.

Methods

Simulations employed a simple RL algorithm, which was used to generate hypothetical neural activations that would be expected to be observed in functional magnetic resonance imaging (fMRI) studies of RL. Similar RL models were incorporated within a GLM-based analysis method including derivatives, with individual differences in the resulting GLM-derived beta parameters being evaluated with respect to the free parameters of the RL model or being submitted to other validation analyses.

Results

Initial simulations demonstrated that the conventional approach to fitting RL models to RPE responses is more likely to reflect individual differences in a reinforcement efficacy construct (lambda) rather than learning rate (alpha). The proposed method, adding a derivative regressor to the GLM, provides a second regressor which reflects the learning rate. Validation analyses were performed including examining another comparable method which yielded highly similar results, and a demonstration of sensitivity of the method in presence of fMRI-like noise.

Conclusion

Overall, the findings underscore the importance of the lambda parameter for interpreting individual differences in RPE-coupled neural activity, and validate a novel neural metric of the modulation of such activity by individual differences in the learning rate. The method is expected to find application in understanding aberrant reinforcement learning across different psychiatric patient groups including major depression and substance use disorder.

Women with more severe premenstrual syndrome have an enhanced anticipatory reward processing: a magnetoencephalography study

Laboratory studies reveal that young women with premenstrual syndrome (PMS) often exhibit decreased reward processing during the late luteal phase. However, studies based on the self-reports find opposite results (e.g., higher craving for high-sweet-fat food). These differences may lie in the difference between the stimulus used and measuring the different aspects of the reward. The present study was designed to expand previous work by using a classic monetary reward paradigm, simultaneously examining the motivational (i.e., reward anticipation, "wanting") and emotional (i.e., reward outcome, "liking") components of reward processing in women with high premenstrual symptoms (High PMS). College female students in their early twenties with High PMS (n = 20) and low premenstrual symptoms (Low PMS, n = 20) completed a monetary incentive delay task during their late luteal phase when the premenstrual symptoms typically peak. Brain activities in the reward anticipation phase and outcome phase were recorded using the magnetoencephalographic (MEG) imaging technique. No group differences were found in various behavioral measurements. For the MEG results, in the anticipation phase, when High PMS participants were presented with cues that predicted the upcoming monetary gains, they showed higher event-related magnetic fields (ERFs) than when they were presented with neutral non-reward cues. This pattern was reversed in Low PMS participants, as they showed lower reward cue-elicited ERFs than non-reward cue-elicited ones (cluster mass = 2560, cluster size = 891, p = .03, corrected for multiple comparisons), mainly in the right medial orbitofrontal and lateral orbitofrontal cortex (cluster mass = 375, cluster size = 140, p = .03, corrected for multiple comparisons). More importantly, women with High PMS had an overall significantly higher level of ERFs than women with Low PMS (cluster mass = 8039, cluster size = 2937, p = .0009, corrected for multiple comparisons) in the bilateral precentral gyrus, right postcentral gyrus, and left superior temporal gyrus (right: cluster mass = 410, cluster size = 128, p = .03; left: cluster mass = 352, cluster size = 98, p = .05; corrected for multiple comparisons). In the outcome phase, women with High PMS showed significantly lower theta power than the Low PMS ones for the expected non-reward feedback in the bilateral temporal-parietal regions (cluster mass = 47620, cluster size = 18308, p = .01, corrected for multiple comparisons). These findings reveal that the severity of PMS might alter reward anticipation. Specifically, women with High PMS displayed increased brain activities to reward-predicting cues and increased action preparation after the cues appear.

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

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

The effects of Lysergic Acid Diethylamide (LSD) on the Positive Valence Systems: A Research Domain Criteria (RDoC)-Informed Systematic Review

BACKGROUND AND OBJECTIVES

The renewed interest in psychedelic research provides growing evidence of potentially unique effects on various aspects of reward processing systems. Using the Research Domain Criteria (RDoC) framework, as proposed by the National Institute of Mental Health, we aim to synthesize the existing literature concerning the impact of lysergic acid diethylamide (LSD) on the RDoC's Positive Valence Systems (PVS) domain, and to identify potential avenues for further research.

METHODS

Two LSD-related terms (lysergic acid diethylamide and LSD) and 13 PVS-related terms (reward, happiness, bliss, motivation, reinforcement learning, operant, conditioning, satisfaction, decision making, habit, valence, affect, mood) were used to search electronic databases such as PubMed, Scopus, PsychINFO, and Web of Science for relevant articles. A manual search of the reference list resulted in nine additional articles. After screening, articles and data were evaluated and included based on their relevance to the objective of investigating the effects of LSD on the PVS. Articles and data were excluded if they did not provide information about the PVS, were observational in nature, lacked comparators or reference groups, or were duplicates. A risk of bias assessment was performed using the National Toxicology Program's Office of Health Assessment and Translation (NTP OHAT) risk of bias (RoB) tool. Data from the included articles were collected and structured based on the RDoC bio-behavioral matrix, specifically focusing on the PVS domain and its three constituent constructs: reward responsiveness, reward learning, and reward valuation.

RESULTS

We reviewed 28 clinical studies with 477 participants. Lysergic acid diethylamide, assessed at self-report (23 studies), molecular (5 studies), circuit (4 studies), and paradigm (3 studies) levels, exhibited dose-dependent mood improvement (20 short-term and 3 long-term studies). The subjective and neural effects of LSD were linked to the 5-HT2A receptor (molecular). Animal studies (14 studies) suggested LSD could mildly reinforce conditioned place preference without aversion and reduce responsiveness to other rewards. Findings on reward learning were inconsistent but hinted at potential associative learning enhancements. Reward valuation measures indicated potential reductions in effort expenditure for other reinforcers.

CONCLUSION

Our findings are consistent with our previous work, which indicated classical psychedelics, primarily serotonin 2A receptor agonists, enhanced reward responsiveness in healthy individuals and patient populations. Lysergic acid diethylamide exhibits a unique profile in the reward learning and valuation constructs. Using the RDoC-based framework, we identified areas for future research, enhancing our understanding of the impact of LSD on reward processing. However, applying RDoC to psychedelic research faces limitations due to diverse study designs that were not initially RDoC-oriented. Limitations include subjective outcome measure selection aligned with RDoC constructs and potential bias in synthesizing varied studies. Additionally, some human studies were open-label, introducing potential bias compared to randomized, blinded studies.

Interpersonal Stress and Late Adolescent Depressive Symptoms: Moderation by Perceptual Sensitivity to Facial Expression of Anger

The interpersonal theories of depression highlight the role of interpersonal stress and individual's sensitivity to social rejection in the development of depression. However, previous research has tested their respective effects, whereas whether or not these two factors interact to affect depression, especially in ways of differential susceptibility or diathesis-stress, remains unknown. By adopting a morphed facial expressions recognition paradigm, the current study investigated the potential moderating role of perceptual sensitivity to facial expressions, especially that to angry expression which signaled social rejection, in the association between interpersonal stress and adolescent depressive symptoms. A total of 186 Chinese late adolescents (Mage = 21.16 ± 1.81 years; 73.7% females) participated in this study. The results demonstrated that perceptual sensitivity for angry faces, but not sad or happy faces, functioned as a plasticity factor significantly moderating the effect of interpersonal stress on depressive symptoms, which was consistent with hypothesis of differential susceptibility rather than diathesis-stress. No interactions were observed regarding non-interpersonal dimensions. These results were robust and survived a series of sensitivity analyses, including k-fold cross-validation test. The current findings highlight the crucial role of perceptual sensitivity to angry expression in explaining individual differences behind the links between interpersonal stress and adolescent depressive symptoms.

Sex matters: acute functional connectivity changes as markers of remission in late-life depression differ by sex

The efficacy of antidepressant treatment in late-life is modest, a problem magnified by an aging population and increased prevalence of depression. Understanding the neurobiological mechanisms of treatment response in late-life depression (LLD) is imperative. Despite established sex differences in depression and neural circuits, sex differences associated with fMRI markers of antidepressant treatment response are underexplored. In this analysis, we assess the role of sex on the relationship of acute functional connectivity changes with treatment response in LLD. Resting state fMRI scans were collected at baseline and day one of SSRI/SNRI treatment for 80 LLD participants. One-day changes in functional connectivity (differential connectivity) were related to remission status after 12 weeks. Sex differences in differential connectivity profiles that distinguished remitters from non-remitters were assessed. A random forest classifier was used to predict the remission status with models containing various combinations of demographic, clinical, symptomatological, and connectivity measures. Model performance was assessed with area under the curve, and variable importance was assessed with permutation importance. The differential connectivity profile associated with remission status differed significantly by sex. We observed evidence for a difference in one-day connectivity changes between remitters and non-remitters in males but not females. Additionally, prediction of remission was significantly improved in male-only and female-only models over pooled models. Predictions of treatment outcome based on early changes in functional connectivity show marked differences between sexes and should be considered in future MR-based treatment decision-making algorithms.

Uncovering the Neural Correlates of Anhedonia Subtypes in Major Depressive Disorder: Implications for Intervention Strategies

Major depressive disorder (MDD) represents a serious public health concern, negatively affecting individuals' quality of life and making a substantial contribution to the global burden of disease. Anhedonia is a core symptom of MDD and is associated with poor treatment outcomes. Variability in anhedonia components within MDD has been observed, suggesting heterogeneity in psychopathology across subgroups. However, little is known about anhedonia subgroups in MDD and their underlying neural correlates across subgroups. To address this question, we employed a hierarchical cluster analysis based on Temporal Experience of Pleasure Scale subscales in 60 first-episode, drug-naive MDD patients and 32 healthy controls. Then we conducted a connectome-wide association study and whole-brain voxel-wise functional analyses for identified subgroups. There were three main findings: (1) three subgroups with different anhedonia profiles were identified using a data mining approach; (2) several parts of the reward network (especially pallidum and dorsal striatum) were associated with anticipatory and consummatory pleasure; (3) different patterns of within- and between-network connectivity contributed to the disparities of anhedonia profiles across three MDD subgroups. Here, we show that anhedonia in MDD is not uniform and can be categorized into distinct subgroups, and our research contributes to the understanding of neural underpinnings, offering potential treatment directions. This work emphasizes the need for tailored approaches in the complex landscape of MDD. The identification of homogeneous, stable, and neurobiologically valid MDD subtypes could significantly enhance our comprehension and management of this multifaceted condition.

Neural Correlates of Anhedonia in Major Depressive Disorder: Insights from Concurrent Analysis of Feedback-Related Negativity and Stimulus-Preceding Negativity

Purpose

Anhedonia, a core symptom of major depressive disorder (MDD), is explored in this study, focusing on the neural underpinnings through the examination of two event-related potential (ERP) components: feedback-related negativity (FRN) and stimulus-preceding negativity (SPN).

Patients and Methods

This cross-sectional study was conducted in China from March 2022 to March 2023. It involved 35 MDD patients and 31 healthy controls (HC) participating in a modified 2-door task with simultaneous EEG recordings. Depression severity and anhedonia were assessed using the Hamilton Depression Scale (HAMD) and the Temporal Experience of Pleasure Scale (TEPS-CV), respectively. FRN and SPN metrics, along with correlations with each other and clinical assessments, were examined.

Results

In comparison to the HC group, the MDD group exhibited significantly lower scores in TEPS-CV (t = 2.854, p = 0.006) and its subscales (t = -3.596, p = 0.001 and t = 2.434, p = 0.018, respectively), along with consistently reduced amplitudes of FRN (F 1.64= 4.726, p = 0.033) and SPN (F 1.64= 4.195, p = 0.045) across all conditions. Limited correlations were observed between ERP metrics and clinical indicators, except for positive correlations between FRN amplitudes (loss minus win) and HAMD scores (r = 0.392, p = 0.020), and SPN amplitudes after losing (SPN-L) and TEPS-CV consumption subscale scores (r = 0.357, p = 0.035). Notably, while the HC group displayed no significant FRN-SPN correlations, the MDD group exhibited positive FRN-SPN correlations under distinct conditions (r = 0.376, p = 0.026 and r = 0.355, p = 0.037, respectively).

Conclusion

Our data reveal subjective and objective anhedonia in both consumption and anticipation, suggesting a shared impairment in reward feedback processing and anticipatory neural mechanisms in individuals with MDD. These findings deepen our understanding of anhedonia's neural foundations and may guide targeted interventions for this core symptom.

Striatal correlates of Bayesian beliefs in self-efficacy in adolescents and their relation to mood and autonomy: a pilot study

Major depressive disorder often originates in adolescence and is associated with long-term functional impairment. Mechanistically characterizing this heterogeneous illness could provide important leads for optimizing treatment. Importantly, reward learning is known to be disrupted in depression. In this pilot fMRI study of 21 adolescents (16-20 years), we assessed how reward network disruption impacts specifically on Bayesian belief representations of self-efficacy (SE-B) and their associated uncertainty (SE-U), using a modified instrumental learning task probing activation induced by the opportunity to choose, and an optimal Hierarchical Gaussian Filter computational model. SE-U engaged caudate, nucleus accumbens (NAcc), precuneus, posterior parietal and dorsolateral prefrontal cortex (PFWE < 0.005). Sparse partial least squares analysis identified SE-U striatal activation as associating with one's sense of perceived choice and depressive symptoms, particularly anhedonia and negative feelings about oneself. As Bayesian uncertainty modulates belief flexibility and their capacity to steer future actions, this suggests that these striatal signals may be informative developmentally, longitudinally and in assessing response to treatment.

Electrical brain activations in young children during a probabilistic reward-learning task are associated with behavioral strategy

Both adults and children learn through feedback which events and choices in the environment are associated with higher probability of reward. This probability reward-learning ability is thought to be supported by the development of fronto-striatal reward circuits. Recent developmental studies have applied computational models of reward learning to investigate such learning in children. However, there has been limited development of task tools capable of measuring the cascade of neural reward-learning processes in children. Using a child-version of a probabilistic reward-learning task while recording event-related-potential (ERP) measures of electrical brain activity, this study examined key processes of reward learning in preadolescents (n=30), namely: (1) reward-feedback sensitivity, as measured by the early reward-related frontal ERP positivity, (2) rapid attentional shifting of processing toward favored visual stimuli, as measured by the N2pc component, and (3) longer-latency attention-related responses to reward feedback as a function of behavior strategies (i.e., Win-Stay-Lose-Shift), as measured by the central-parietal P300. Consistent with our prior work in adults, the behavioral findings indicate that preadolescents could learn stimulus-reward outcome associations, but at varying levels of performance. Neurally, poor preadolescent learners (those with slower learning rates) showed greater reward-related positivity amplitudes relative to good learners, suggesting greater reward sensitivity. We also found attention shifting towards to-be-chosen stimuli, as evidenced by the N2pc, but not to more highly rewarded stimuli. Lastly, we found an effect of behavioral learning strategies (i.e., Win-Stay-Lose-Shift) on the feedback-locked P300 over the parietal cortex. These findings provide novel insights into the key neural processes underlying reinforcement learning in preadolescents.

Functional dysconnectivity in youth depression: Systematic review, meta-analysis, and network-based integration

Youth depression has been associated with heterogenous patterns of aberrant brain connectivity. To make sense of these divergent findings, we conducted a systematic review encompassing 19 resting-state fMRI seed-to-whole-brain studies (1400 participants, comprising 795 youths with major depression and 605 matched healthy controls). We incorporated separate meta-analyses of connectivity abnormalities across the levels of the most commonly seeded brain networks (default-mode and limbic networks) and, based on recent additions to the literature, an updated meta-analysis of amygdala dysconnectivity in youth depression. Our findings indicated broad and distributed findings at an anatomical level, which could not be captured by conventional meta-analyses in terms of spatial convergence. However, we were able to parse the complexity of region-to-region dysconnectivity by considering constituent regions as components of distributed canonical brain networks. This integration revealed dysconnectivity centred on central executive, default mode, salience, and limbic networks, converging with findings from the adult depression literature and suggesting similar neurobiological underpinnings of youth and adult depression.

Deficits in doors P300 amplitude during adolescence associated with preschool-onset depression

The psychophysiological underpinnings of preschool-onset depression (PO-MDD) remain underexplored. Moreover, there is currently a limited understanding of the potential impact that PO-MDD might have on neurobiological functions later in development such as general cognitive domains and reward processing. Thus, the current study sought to examine potential neurophysiological differences, measured via electroencephalography (EEG), in adolescents with and without a history of PO-MDD. Participants and their caregivers (N = 138) from a large longitudinal study completed semi-structured clinical interviews at a baseline visit (ages 3-7) to determine PO-MDD status. At a follow-up visit approximately 11 years later, adolescents (ages 13-19) completed the doors gambling task while EEG was recorded to measure event-related potentials (ERPs) elicited by both the doors and feedback stimuli, to index cognitive and reward processing functions (i.e., doors-P300, gain/loss feedback-P300, and RewP). Adolescents with a history of PO-MDD exhibited significantly smaller doors-P300 compared with adolescents with no history of PO-MDD, whereas there were no group differences in gain/loss feedback-P300 or RewP. Additionally, reduced doors-P300 was independently associated with lower baseline income-to-needs ratio, older age, and female gender. The current study suggests that reduced doors-P300 amplitude during adolescence might reflect impaired neurophysiological development related to PO-MDD. Thus, the P300 derived from the doors stimuli might be a valuable neural measure to further our understanding of potential neurophysiological differences associated with early-onset childhood depression.

Altered Putamen Activation for Social Comparison-Related Feedback in Social Anxiety Disorder: A Pilot Study

INTRODUCTION

Social anxiety disorder (SAD) is characterized by abnormal processing of performance-related social stimuli. Previous studies have shown altered emotional experiences and activations of different sub-regions of the striatum during processing of social stimuli in patients with SAD. However, whether and to what extent social comparisons affect behavioural and neural responses to feedback stimuli in patients with SAD is unknown.

MATERIALS AND METHODS

To address this issue, emotional ratings and functional magnetic resonance imaging (fMRI) responses were assessed while patients suffering from SAD and healthy controls (HC) were required to perform a choice task and received performance feedback (correct, incorrect, non-informative) that varied in relation to the performance of fictitious other participants (a few, half, or most of others had the same outcome).

RESULTS

Across all performance feedback conditions, fMRI analyses revealed reduced activations in bilateral putamen when feedback was assumed to be received by only a few compared to half of the other participants in patients with SAD. Nevertheless, analysis of rating data showed a similar modulation of valence and arousal ratings in patients with SAD and HC depending on social comparison-related feedback.

CONCLUSIONS

This suggests altered neural processing of performance feedback depending on social comparisons in patients with SAD.

Transdiagnostic considerations of the relationship between reward sensitivity and psychopathological symptoms - a cross-lagged panel analysis

BACKGROUND

Reward sensitivity constitutes a potential key mechanism regarding the etiology and maintenance of mental disorders, especially depression. However, due to a lack of longitudinal studies, the temporal dynamics are not clear yet. Although some evidence indicates that reward processing could be a transdiagnostic mechanism of disorders, these observations could be also a product of comorbidity with depression. This study aimed at investigating the temporal dynamics of reward sensitivity and the course of psychopathological symptoms in a longitudinal investigation, while taking a possible mediating role of depression into account.

METHODS

We conducted a three-wave longitudinal online survey with a 4-week interval. A total of N = 453 participants filled out all three questionnaires. Reward sensitivity was assessed with the Positive Valence System Scale-21 (PVSS-21), depression with the Patient Health Questionnaire (PHQ-9), eating disorder symptoms with the Eating Disorder Examination-Questionnaire-8 (EDE-Q-8), social anxiety with the Mini-social phobia inventory (Mini-SPIN) and alcohol consumption with the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C). Cross-lagged panels and mediation analyses were calculated using path analyses.

RESULTS

Depressive and eating disorder symptoms predicted reward insensitivity at later points in time. Effects were larger from T2 to T3. A bidirectional relationship concerning social anxiety was found. Higher alcohol consumption predicted higher reward sensitivity. Depression at T2 fully mediated the association between psychopathological symptoms at T1 and reward sensitivity at T3 for social anxiety and eating disorder symptoms.

CONCLUSIONS

Our findings imply that reduced reward sensitivity seems to be a consequence rather than an antecedent of psychopathological symptoms. Comorbid depression plays a crucial role in other mental disorders regarding observed hyposensitivity towards rewards. Therefore, our results do not support a transdiagnostic notion of reward sensitivity, but they indicate a potential role of reward sensitivity for symptom persistence.

TRIAL REGISTRATION

The study was preregistered at the Open Science Framework (OSF) ( https://archive.org/details/osf-registrations-6n3s8-v1 ; registration DOI https://doi.org/10.17605/OSF.IO/6N3S8 ).

Common and distinct patterns of task-related neural activation abnormalities in patients with remitted and current major depressive disorder: A systematic review and coordinate-based meta-analysis

Whether remitted major depressive disorder (rMDD) and MDD present common or distinct neuropathological mechanisms remains unclear. We performed a meta-analysis of task-related whole-brain functional magnetic resonance imaging (fMRI) using anisotropic effect-size signed differential mapping software to compare brain activation between rMDD/MDD patients and healthy controls (HCs). We included 18 rMDD studies (458 patients and 476 HCs) and 120 MDD studies (3746 patients and 3863 HCs). The results showed that MDD and rMDD patients shared increased neural activation in the right temporal pole and right superior temporal gyrus. Several brain regions, including the right middle temporal gyrus, left inferior parietal, prefrontal cortex, left superior frontal gyrus and striatum, differed significantly between MDD and rMDD. Meta-regression analyses revealed that the percentage of females with MDD was positively associated with brain activity in the right lenticular nucleus/putamen. Our results provide valuable insights into the underlying neuropathology of brain dysfunction in MDD, developing more targeted and efficacious treatment and intervention strategies, and more importantly, providing potential neuroimaging targets for the early screening of MDD.

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

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