Reward function as an outcome predictor in youth with mood and anxiety symptoms

Neural correlates of anhedonia in young adults with subthreshold depression: A graph theory approach for cortical-subcortical structural covariance

BACKGROUND

Anhedonia is an enduring symptom of subthreshold depression (StD) and predict later onset of major depressive disorder (MDD). Brain structural covariance describes the inter-regional distribution of morphological changes compared to healthy controls (HC) and reflects brain maturation and disease progression. We investigated neural correlates of anhedonia from the structural covariance.

METHODS

T1-weighted brain magnetic resonance images were acquired from 79 young adults (26 StD, 30 MDD, and 23 HC). Intra-individual structural covariance networks of 68 cortical surface area (CSAs), 68 cortical thicknesses (CTs), and 14 subcortical volumes were constructed. Group-level hubs and principal edges were defined using the global and regional graph metrics, compared between groups, and examined for the association with anhedonia severity.

RESULTS

Global network metrics were comparable among the StD, MDD, and HC. StD exhibited lower centralities of left pallidal volume than HC. StD showed higher centralities than HC in the CSAs of right rostral anterior cingulate cortex (ACC) and pars triangularis, and in the CT of left pars orbitalis. Less anhedonia was associated with higher centralities of left pallidum and right amygdala, higher edge betweenness centralities in the structural covariance (EBSC) of left postcentral gyrus-parahippocampal gyrus and LIPL-right amygdala. More anhedonia was associated with higher centralities of left inferior parietal lobule (LIPL), left postcentral gyrus, left caudal ACC, and higher EBSC of LIPL-left postcentral gyrus, LIPL-right lateral occipital gyrus, and left caudal ACC-parahippocampal gyrus.

LIMITATIONS

This study has a cross-sectional design.

CONCLUSIONS

Structural covariance of brain morphologies within the salience and limbic networks, and among the salience-limbic-default mode-somatomotor-visual networks, are possible neural correlates of anhedonia in depression.

Augmented Depression Therapy for young adults: A mixed methods randomised multiple baseline case series evaluation

Augmented Depression Therapy (ADepT) is an individual psychotherapy for depression, which has been shown to be effective in the general adult population. A randomised multiple baseline case series evaluated the feasibility, acceptability, and effectiveness of ADepT in young adults (aged 20-24). Eleven depressed young adults were recruited from a UK university wellbeing service to receive ADepT during the COVID-19 pandemic, with outcomes evaluated relative to pre-specified continuation targets. All participants received a minimum adequate treatment dose (>60% target); 89% judged ADepT as acceptable and satisfactory and would recommend it to others (>60% target); only 9% showed reliable deterioration for depression or wellbeing (meeting <30% target); and there were no trial- or treatment-related serious adverse events. Qualitative interviews revealed most participants were satisfied with and experienced benefits from ADepT. At post-treatment, reliable improvement was shown by 33% of participants for depression and 67% of participants for wellbeing (not meeting target of both >60%), with medium effect size improvements for depression (g = 0.78) and large effect size improvement for wellbeing (g = 0.93; not meeting target of both >0.80). ADepT is feasible, acceptable, and safe in young adults but may require modification to maximise effectiveness. Further research outside of the COVID-19 pandemic is warranted.

C-Reactive Protein Does Not Predict Future Depression Onset in Adolescents: Preliminary Findings from a Longitudinal Study

Introduction: Neuroinflammatory processes have been extensively implicated in the underlying neurobiology of numerous neuropsychiatric disorders. Elevated C-reactive protein (CRP), an indicator of nonspecific inflammation commonly utilized in clinical practice, has been associated with depression in adults. In adolescents, our group previously found CRP to be associated with altered neural reward function but not with mood and anxiety symptoms assessed cross-sectionally. We hypothesized that the distinct CRP findings in adolescent versus adult depression may be due to chronicity, with neuroinflammatory effects on psychiatric disorders gradually accumulating over time. Here, we conducted a longitudinal study to evaluate if CRP levels predicted future onset or progression of depression in adolescents. Methods: Participants were 53 adolescents (age = 14.74 ± 1.92 years, 35 female), 40 with psychiatric symptoms and 13 healthy controls. At baseline, participants completed semistructured diagnostic evaluations; dimensional assessments for anxiety, depression, anhedonia, and suicidality severity; and bloodwork to quantify CRP levels. Clinical assessments were repeated at longitudinal follow-up after ∼1.5 years. Spearman's correlation between CRP levels and follow-up symptom severity were controlled for body mass index, age, sex, and follow-up interval and considered significant at the two-tailed, Bonferroni-adjusted p < 0.05 level. Results: After correction for multiple comparisons, no relationships were identified between baseline CRP levels and follow-up symptom severity. Conclusion: CRP levels were not significantly associated with future psychiatric symptoms in adolescents in this preliminary analysis. This may suggest that CRP is not a useful biomarker for adolescent depression and anxiety. However, future longitudinal studies with larger sample sizes and incorporating additional indicators of neuroinflammation are needed.

Neural sensitivity following stress predicts anhedonia symptoms: a 2-year multi-wave, longitudinal study

Animal models of depression show that acute stress negatively impacts functioning in neural regions sensitive to reward and punishment, often manifesting as anhedonic behaviors. However, few human studies have probed stress-induced neural activation changes in relation to anhedonia, which is critical for clarifying risk for affective disorders. Participants (N = 85, 12-14 years-old, 53 female), oversampled for risk of depression, were administered clinical assessments and completed an fMRI guessing task during a baseline (no-stress) period to probe neural response to receipt of rewards and losses. After the initial task run of the fMRI guessing task, participants received an acute stressor and then, were re-administered the guessing task. Including baseline, participants provided up to 10 self-report assessments of life stress and symptoms over a 2 year period. Linear mixed-effects models estimated whether change in neural activation (post- vs. pre-acute stressor) moderated the longitudinal associations between life stress and symptoms. Primary analyses indicated that adolescents with stress-related reductions in right ventral striatum response to rewards exhibited stronger longitudinal associations between life stress and anhedonia severity (β = -0.06, 95%CI[-0.11, -0.02], p = 0.008, pFDR = 0.048). Secondary analyses showed that longitudinal positive associations between life stress and depression severity were moderated by stress-related increases in dorsal striatum response to rewards (left caudate β = 0.11, 95%CI[0.07,0.17], p < 0.001, pFDR = 0.002; right caudate β = 0.07, 95%CI[0.02,0.12], p = 0.002, pFDR = 0.003; left putamen β = 0.09, 95%CI[0.04, 0.14], p < 0.001, pFDR = 0.002; right putamen β = 0.08, 95%CI[0.03, 0.12], p < 0.001, pFDR = 0.002). Additionally, longitudinal positive associations among life stress and anxiety severity were moderated by stress-related reductions in dorsal anterior cingulate cortex (β = -0.07, 95%CI[-0.12,.02], p = 0.008, pFDR = 0.012) and right anterior insula (β = -0.07, 95%CI[-0.12,-0.02], p = 0.002, pFDR = 0.006) response to loss. All results held when adjusting for comorbid symptoms. Results show convergence with animal models, highlighting mechanisms that may facilitate stress-induced anhedonia as well as a separable pathway for the emergence of depressive and anxiety symptoms.

A feasibility study of goal-directed network-based real-time fMRI neurofeedback for anhedonic depression

Anhedonia is a hallmark symptom of depression that often lacks adequate interventions. The translational gap remains in clinical treatments based on neural substrates of anhedonia. Our pilot study found that depressed individuals depended less on goal-directed (GD) reward learning (RL), with reduced reward prediction error (RPE) BOLD signal. Previous studies have found that anhedonia is related to abnormal activities and/or functional connectivities of the central executive network (CEN) and salience network (SN), both of which belong to the goal-directed system. In addition, it was found that real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF) could improve the balance between CEN and SN in healthy individuals. Therefore, we speculate that rt-fMRI NF of the CEN and SN associated with the GD system may improve depressive and/or anhedonic symptoms. Therefore, this study (1) will examine individuals with anhedonic depression using GD-RL behavioral task, combined with functional magnetic resonance imaging and computational modeling to explore the role of CEN/SN deficits in anhedonic depression; and (2) will utilize network-based rt-fMRI NF to investigate whether it is feasible to regulate the differential signals of brain CEN/SN of GD system through rt-fMRI NF to alleviate depressive and/or anhedonic symptoms. This study highlights the need to elucidate the intervention effects of rt-fMRI NF and the underlying computational network neural mechanisms.

Personality characteristics, not clinical symptoms, are associated with anhedonia in a community sample: A preliminary investigation

Anhedonia is a salient transdiagnostic psychiatric symptom associated with increased illness severity and chronicity. Anhedonia is also present to varying degrees in non-clinical cohorts. Here, we sought to examine factors influencing expression of anhedonia. Participants (N = 335) were recruited through the Nathan Kline Institute-Rockland Sample, an initiative to deeply phenotype a large community sample across the lifespan. Utilizing a data-driven approach, we evaluated associations between anhedonia severity, indexed by Snaith-Hamilton Pleasure Scale (SHAPS), and 20 physical, developmental, and clinical measures, including Structured Clinical Interview for DSM-IV, Beck Depression Inventory, State-Trait Anxiety Inventory, NEO Five-Factor Inventory-3 (NEO-FFI-3), BMI, Hemoglobin A1C, and demography. Using a bootstrapped AIC-based backward selection algorithm, seven variables were retained in the final model: NEO-FFI-3 agreeableness, extraversion, and openness to experience; BMI; sex; ethnicity; and race. Though median SHAPS scores were greater in participants with psychiatric diagnoses (18.5) than those without (17.0) (U = 12238.5, z = 2.473, p = 0.013), diagnosis and symptom measures were not retained as significant predictors in the final robust linear model. Participants scoring higher on agreeableness, extraversion, and openness to experience reported significantly lower anhedonia. These results demonstrate personality as a mild-to-moderate but significant driver of differences in experiencing pleasure in a community sample.

C-reactive protein does not predict future depression onset in adolescents: preliminary findings from a longitudinal study

Introduction

Neuroinflammatory processes have been extensively implicated in the underlying neurobiology of numerous neuropsychiatric disorders. Elevated C-reactive protein (CRP), an indicator of non-specific inflammation commonly utilized in clinical practice, has been associated with depression in adults. In adolescents, our group previously found CRP to be associated with altered neural reward function but not with mood and anxiety symptoms assessed cross-sectionally. We hypothesized that the distinct CRP findings in adolescent vs. adult depression may be due to chronicity, with neuroinflammatory effects on psychiatric disorders gradually accumulating over time. Here, we conducted a longitudinal study to evaluate if CRP levels predicted future onset or progression of depression in adolescents.

Methods

Participants were 53 adolescents (ages 14.74 ± 1.92, 35 female), 40 with psychiatric symptoms and 13 healthy controls. At baseline, participants completed semi-structured diagnostic evaluations; dimensional assessments for anxiety, depression, anhedonia, and suicidality severity; and bloodwork to quantify CRP levels. Clinical assessments were repeated at longitudinal follow-up after approximately 1.5 years. Spearman's correlation between CRP levels and follow-up symptom severity were controlled for BMI, age, sex, and follow-up interval and considered significant at the two-tailed, Bonferroni-adjusted p < 0.05 level.

Results

After correction for multiple comparisons, no relationships were identified between baseline CRP levels and follow-up symptom severity.

Conclusion

CRP levels were not significantly associated with future psychiatric symptoms in adolescents in this preliminary analysis. This may suggest that CRP is not a useful biomarker for adolescent depression and anxiety. However, future longitudinal studies with larger sample sizes and incorporating additional indicators of neuroinflammation are needed.

The relationship between disrupted anhedonia-related circuitry and suicidal ideation in major depressive disorder: A network-based analysis

BACKGROUND

Several epidemiological studies and psychological models have suggested that major depressive disorder (MDD) with anhedonia is associated with suicidal ideation (SI). However, little is known about whether the functional network pattern and intrinsic topologically disrupted in patients with anhedonia are related to SI.

METHODS

The resting-fMRI by applying network-based statistic (NBS) and graph-theory analyses was estimated in 273 patients with MDD (144 high anhedonia [HA], 129 low anhedonia [LA]) and 150 healthy controls. In addition, we quantified the SI scores of each patient. Finally, the mediation analysis assessed whether anhedonia symptoms could mediate the relationship between anhedonia-related network metrics and SI.

RESULT

The NBS analysis demonstrated that individuals with HA have a single abnormally increased functional connectivity component in a frontal-limbic circuit (termed the "anhedonia-related network", including the frontal cortex, striatum, anterior cingulate cortex and amygdala). The graph-theory analysis demonstrated that the anhedonia-related network showed a significantly disrupted topological organization (lower gamma and lambda), which the small-world property trend randomized. Furthermore, the anhedonia symptoms could mediate the relationship between the anhedonia-related network metrics (the mean functional connectivity values, the area under the curves values of gamma and nodal local efficiency in nucleus accumbens) and SI.

CONCLUSIONS

We found that disruption of the reward-related network in MDD leads to SI through anhedonia symptoms. These findings show the abnormal topological construction of functional brain network organization in anhedonia, shedding light on the neurological processes underlying SI in MDD patients with anhedonia symptoms.

Neural Sensitivity following Stress Predicts Anhedonia Symptoms: A 2-Year Multi-wave, Longitudinal Study

Animal models of depression show that acute stress negatively impacts functioning in neural regions sensitive to reward and punishment, often manifesting as anhedonic behaviors. However, few human studies have probed stress-induced neural activation changes in relation to anhedonia, which is critical for clarifying risk for affective disorders. Participants (N = 85 , 12-14-years-old, 53 female), oversampled for risk of depression, were administered clinical assessments and completed an fMRI guessing task to probe neural response to receipt of rewards and losses. After the initial task run, participants received an acute stressor and then, were re-administered the guessing task. Including baseline, participants provided up to 10 self-report assessments of life stress and symptoms over a 2-year period. Linear mixed-effects models estimated whether change in neural activation (post- vs. pre-acute stressor) moderated the longitudinal associations between life stress and symptoms over time. Primary analyses indicated that adolescents with stress-related reductions in right ventral striatum response to rewards exhibited stronger longitudinal associations between life stress and anhedonia severity p F D R = . 048 . Secondary analyses showed that longitudinal associations among life stress and depression severity were moderated by stress-related increases in dorsal striatum response to rewards p F D R < . 002 . Additionally, longitudinal associations among life stress and anxiety severity were moderated by stress-related reductions in dorsal anterior cingulate cortex and right anterior insula response to loss p F D R ≤ . 012 . All results held when adjusting for comorbid symptoms. Results show convergence with animal models, highlighting mechanisms that may facilitate stress-induced anhedonia as well as a separable pathway for the emergence of depressive and anxiety symptoms.

Structural and functional deficits and couplings in severe and moderate OCD

Changes in gray matter volume and functional connections have been frequently observed in patients with obsessive compulsive disorder. However, different grouping may cause diverse volume alterations and could draw more adverse conclusions about the pathophysiology of obsessive compulsive disorder(OCD). Most of them preferred to divide subjects into patients and healthy controls, rather than a detailed subgroup. Moreover, multimodal neuroimaging studies about structural-functional defects and couplings are rather rare. Our aim was to explore gray matter volume(GMV) and functional networks abnormalities induced by structural deficits based on severity of Yale-Brown Obsessive Compulsive Scale(Y-BOCS) symptom including OCD patients with severe(S-OCD, n = 31) and moderate symptoms(M-OCD, n = 42) and healthy controls (HCs, n = 54); Voxel-based morphometry(VBM) method was used to detect GMV differences among three groups, then used as masks according to one-way analysis of variance(ANOVA) results for the subsequent resting-state functional connectivity(rs-FC) analysis. Besides, correlation and subgroup analysis were performed to detect the potential roles of structural deficits between every two groups. ANOVA analysis showed that both S-OCD and M-OCD had increased volume in anterior cingulate cortex(ACC), left precuneus(L-Pre) and paracentral lobule(PCL), postcentral gyrus, left inferior occipital gyrus(L-IOG) and right superior occipital gyrus(R-SOG) and bilateral cuneus, middle occipital gyrus(MOG), and calcarine. Additionally, increased connections between Pre and angular gyrus(AG) and inferior parietal lobule(IPL) have been found. Moreover, connections between the left cuneus and lingual gyrus, between IOG and left lingual gyrus, fusiform and between L-MOG and cerebellum were also included. Subgroup analysis showed that decreased GMV in left caudate was negatively correlated with compulsion and total score in patients with moderate symptom compared to HCs. Our findings indicated that altered GMV in occipital-related regions, Pre, ACC and PCL and the disrupted FC networks including MOG-cerebellum and Pre-AG and IPL. Moreover, subgroup GMV analysis furtherly revealed negative associations between GMV changes and Y-BOCS symptom, offering preparatory proof for the involvement of structural and functional deficits in cortical-subcortical circuitry. Thus, they could provide insights into the neurobiological basis.

Reward-related neural dysfunction in youth with a history of suicidal ideation: The importance of temporal predictability

Abnormal reward processing is an important yet understudied risk factor for suicide. Recent neuroimaging studies have found that suicidality is associated with abnormal reward-related neural reactivity and connectivity across a wide range of brain regions and circuits. The varying, and oftentimes discrepant, findings have hindered progress in elucidating the neurobiological link between reward processing dysfunction and suicide risk. Some of this variability is likely related to different reward-related paradigms that are utilized across studies. The primary aim of the current study was to address these issues by comparing neural reactivity between youth with and without a history of suicidal ideation during direct manipulation of reward parameters. A total of 108 unmedicated youth, ages 17-19, were classified into two groups: 1) history of suicidal ideation (n = 39) and 2) no history of suicidal ideation (n = 69). All participants completed a novel reward anticipation task probing anticipation of predictable (P-reward) and unpredictable (U-reward) monetary reward. Results revealed that compared with controls, youth with a history of suicidal ideation exhibited increased neural activation in the dorsal anterior cingulate cortex (dACC) and right anterior insula (aINS) during anticipation of U-reward. There were no group differences during anticipation of P-reward. These findings suggest that propensity for suicidal ideation may be related to specific abnormalities during anticipation of U-reward, but not P-reward.

Neural function underlying reward expectancy and attainment in adolescents with diverse psychiatric symptoms

Reward dysfunction has been hypothesized to play a key role in the development of psychiatric conditions during adolescence. To help capture the complexity of reward function in youth, we used the Reward Flanker fMRI Task, which enabled us to examine neural activity during expectancy and attainment of both certain and uncertain rewards. Participants were 84 psychotropic-medication-free adolescents, including 67 with diverse psychiatric conditions and 17 healthy controls. Functional MRI used high-resolution acquisition and high-fidelity processing techniques modeled after the Human Connectome Project. Analyses examined neural activation during reward expectancy and attainment, and their associations with clinical measures of depression, anxiety, and anhedonia severity, with results controlled for family-wise errors using non-parametric permutation tests. As anticipated, reward expectancy activated regions within the fronto-striatal reward network, thalamus, occipital lobe, superior parietal lobule, temporoparietal junction, and cerebellum. Unexpectedly, however, reward attainment was marked by widespread deactivation in many of these same regions, which we further explored using cosine similarity analysis. Across all subjects, striatum and thalamus activation during reward expectancy negatively correlated with anxiety severity, while activation in numerous cortical and subcortical regions during reward attainment positively correlated with both anxiety and depression severity. These findings highlight the complexity and dynamic nature of neural reward processing in youth.

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

BACKGROUND

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSION

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

Multimodal Investigations of Reward Circuitry and Anhedonia in Adolescent Depression

Depression is a highly prevalent condition with devastating personal and public health consequences that often first manifests during adolescence. Though extensively studied, the pathogenesis of depression remains poorly understood, and efforts to stratify risks and identify optimal interventions have proceeded slowly. A major impediment has been the reliance on an all-or-nothing categorical diagnostic scheme based solely on whether a patient endorses an arbitrary number of common symptoms for a sufficiently long period. This approach masks the well-documented heterogeneity of depression, a disorder that is highly variable in presentation, severity, and course between individuals and is frequently comorbid with other psychiatric conditions. In this targeted review, we outline the limitations of traditional diagnosis-based research and instead advocate an alternative approach centered around symptoms as unique dimensions of clinical dysfunction that span across disorders and more closely reflect underlying neurobiological abnormalities. In particular, we highlight anhedonia-the reduced ability to anticipate and experience pleasure-as a specific, quantifiable index of reward dysfunction and an ideal candidate for dimensional investigation. Anhedonia is a core symptom of depression but also a salient feature of numerous other conditions, and its severity varies widely within clinical and even healthy populations. Similarly, reward dysfunction is a hallmark of depression but is evident across many psychiatric conditions. Reward function is especially relevant in adolescence, a period characterized by exaggerated reward-seeking behaviors and rapid maturation of neural reward circuitry. We detail extensive work by our research group and others to investigate the neural and systemic factors contributing to reward dysfunction in youth, including our cumulative findings using multiple neuroimaging and immunological measures to study depressed adolescents but also trans-diagnostic cohorts with diverse psychiatric symptoms. We describe convergent evidence that reward dysfunction: (a) predicts worse clinical outcomes, (b) is associated with functional and chemical abnormalities within and beyond the neural reward circuitry, (c) is linked to elevated peripheral levels of inflammatory biomarkers, and (d) manifests early in the course of illness. Emphasis is placed on high-resolution neuroimaging techniques, comprehensive immunological assays, and data-driven analyses to fully capture and characterize the complex, interconnected nature of these systems and their contributions to adolescent reward dysfunction.