The neurobiology of anhedonia and other reward-related deficits

The real-world impact of cariprazine on short- and long-term disability outcomes among commercially insured patients in the United States

AIM

To compare all-cause and mental health (MH)-related short-term and long-term disability leaves and associated costs among patients in the United States with bipolar disorder (BP), major depressive disorder (MDD), or schizophrenia spectrum disorders (SCZ) before versus after cariprazine initiation.

METHODS

Merative MarketScan Commercial and Health and Productivity Management (HPM) databases (January 2016 to December 2021) were utilized to identify adults diagnosed with BP, MDD, or SCZ with ≥2 pharmacy cariprazine claims (first claim = index), ≥3 months of cariprazine use (adjunctively for MDD), and continuous commercial insurance coverage and HPM eligibility during baseline (12 months pre-index) and ≥3 months post-index. Observation continued until cariprazine discontinuation, insurance or HPM eligibility end, 1 year post-index, or HPM data availability end. All-cause and MH-related disability claims, days, and costs were evaluated. Baseline versus post-index rates of disability claims (events) and days were compared using rate ratios (RR); costs were compared using mean cost differences. Comparisons were calculated from generalized estimating equation models. Analyses were replicated separately across indications.

RESULTS

There were 489 patients overall (BP = 238, MDD = 233, SCZ = 18; mean age = 43.3 years; 60.7% female; mean follow-up = 7.6 months). All-cause rates of disability events and days following cariprazine initiation were 29% (RR = 0.71 [95% CI = 0.57, 0.86]) and 28% (0.72 [0.53, 0.94]) lower than baseline, respectively (both p < .05). MH-related rates of disability events and days were 40% (0.60 [0.43, 0.80]) and 43% (0.57 [0.34, 0.84]) lower, respectively (both p < .01). All-cause disability costs were $2,917 lower and MH-related disability costs were $2,482 lower than baseline (40% and 51% decrease, respectively; both p < .01). Results were similar for indication-specific analyses.

LIMITATIONS

Limited generalizability to patients who are unemployed, uninsured, or have public insurance.

CONCLUSIONS

Rates of disability events, days, and mean costs were significantly lower after versus before cariprazine initiation. These results can help contextualize cariprazine's role in managing disability for these patients.

Cognitive impairment and associated neurobehavioral dysfunction in post-COVID syndrome

There is a high prevalence of neuropsychiatric sequelae in post-COVID syndrome, most commonly chronic fatigue, the mechanisms of which remain poorly understood. As altered function of the reward system has been suggested as a causal factor, we aimed to distinguish whether reward processing or task-unspecific cognitive operations are impaired in post-COVID syndrome. Our cohort study included 24 patients diagnosed with post-COVID syndrome and 24 demographically matched healthy controls. Questionnaire assessment of neuropsychiatric symptoms and socio-demographic variables, the Monetary Incentive Delay Task during an fMRI scan, and pupillary measurements were performed. In addition to clinical neuropsychiatric symptoms, participants in the post-COVID group demonstrated significantly slower task performance compared to healthy controls, although the function of behavioral reward circuits appeared unimpaired. However, the influence of rewarding cues on post-COVID patients increased significantly over time during task performance, correlating with temporally delayed activation of the left frontal gyrus and increased activity in task-unspecific brain regions in post-COVID patients. Furthermore, slower reaction times on the task were associated with a lower pupil diameter and a higher pupillary unrest index. This study proposes that post-COVID syndrome is a process that may not affect reward processing, but leads to neural hypoarousal and temporally altered brain activity in frontal and task-unspecific brain regions.

Relationship between anhedonia, separation anxiety, attachment style and suicidality in a large cohort of individuals with mood and anxiety disorders

BACKGROUND

Anhedonia is psychopathological dimension conceptualized as loss of pleasure in several activities. Although typically viewed as a characteristic feature of depressive episodes, anhedonic experience is also seen in other mental disorders. We aimed to investigate the relationship between anhedonia, separation anxiety, and attachment style in a large cohort of outpatients with mood and anxiety disorders, also considering its ties to suicidality.

METHODS

384 consecutively recruited outpatients with mood or anxiety disorders were recruited and assessed with the Structured Clinical Interview for Mood Spectrum-Self Report (MOODS-SR) for anhedonia and suicidality, the Adult Separation Anxiety-Checklist (ASA-27), the Assessment of Adult Attachment Style Questionnaire (ASQ), the Hamilton Rating Scale for Depression (HAMD) and for Anxiety (HAM-A). Anhedonia score was calculated using eight items of the MOODS-SR encompassing the definition of anhedonia.

RESULTS

84 patients were diagnosed with adult separation anxiety disorder only (A-SAD), 32 patients had separation anxiety disorder only during childhood (C-SAD), 77 had both A-SAD and C-SAD, and 191 had no A-SAD/C-SAD. No differences were found in HAM-A and HAM-D scores between the diagnostic groups. Anhedonia score was significantly worse in the two groups with A-SAD. Regression analyses showed that HAM-D (p < .024), ASA-27 (p < .002) total scores and the ASQ domains of Confidence (p < .001) and Discomfort with Closeness (p < .002) were significant predictors of anhedonia. Anhedonia score (p < .001) and ASA-27 (p < .041) total score were significant predictors of suicidal thoughts and behaviors.

CONCLUSIONS

Adult separation anxiety is associated with anhedonia and suicide risk in outpatients with mood and anxiety disorders.

Disrupted maternal behavior in morphine-dependent pregnant rats and anhedonia in their offspring

It is currently estimated that every 15 minutes an infant is born with opioid use disorder and undergoes intense early life trauma due to opioid withdrawal. Clinical research on the long-term consequences of gestational opioid exposure reports increased rates of social, conduct, and emotional disorders in these children. Here, we investigate the impact of perinatal opioid exposure (POE) on behaviors associated with anhedonia and stress in male and female Sprague Dawley rats. Young adult female rats were administered morphine via programmable, subcutaneous micro-infusion pumps before, during, and through one week post gestation. For the first two postnatal weeks, maternal behavior was examined for fragmentation and unpredictability. Unpredictable behavioral patterns were quantitatively characterized as entropy scores. Offspring were assessed for sucrose preference, social behavior, and stress responsivity. Overall, dams that received morphine across gestation displayed significantly less pup-directed behavior with increased fragmentation for nursing and higher entropy scores. In adolescence, male and female rat offspring exposed to morphine displayed reduced sucrose preference and, as adults, spent significantly less time interacting with familiar conspecifics. Changes in social behaviors were linked to increased activity in nondopaminergic cells of mesolimbic reward brain regions. Although no treatment effects were observed in forced swim test performance, corticosterone levels were significantly increased in POE adult males. Together, these results suggest that perinatal morphine exposure promotes anhedonic behavior, possibly due to fragmented and unpredictable maternal behavior in opioid-dependent dams.

Delivering a new generation of translational animal models for depression research

Early animal models of depression focused on developing methods that could predict treatment efficacy and were validated based on pharmacological responses to known antidepressants. As our understanding of major depressive disorder (MDD) and the pharmacology of antidepressants progressed, so did the need for better animal models. This need was met with the development of new disease models, such as the chronic mild stress model, and behavioural readouts such as the sucrose preference test, which more closely aligned with risk factors and symptoms seen in patients. These approaches have supported huge advances in the understanding of how stress affects the brain and impacts on reward-related behaviours. However, there remain significant challenges when trying to model complex psychiatric symptoms and disorders in non-human animals. In this perspective article, a brief history of animal models of depression and associated readouts is discussed with specific reference to the important contributions from Paul Willner. The main discussion then focuses on translational validity and approaches that may support delivering this objective. This is illustrated with the example of the affective bias test and reward learning assays, which have been developed to recapitulate in animals the neuropsychological impairments observed in MDD and modulation by antidepressants.

Psilocybin mitigates behavioral despair and cognitive impairment in treatment-resistant depression model using wistar kyoto rats

Major depressive disorder (MDD) is a leading cause of disability that affects over 300 million people globally. Despite multiple antidepressant trials, approximately one-third of MDD patients remain symptomatic, progressing to treatment-resistant depression (TRD). This persistence possibly is due to the multifaceted etiology of TRD, encompassing biological, psychological, and environmental factors. Chronic stress, prevalent in modern life, significantly contributes to mental health disorders and complicates TRD treatment. This study investigated psilocybin as a potential TRD treatment using a diathesis-stress animal model. Twenty-two male Wistar-Kyoto (WKY) rats were divided into control and stress groups, with the stress group further subdivided to receive either sham treatment or psilocybin as early intervention. Behavioral assessments demonstrated a significant and sustained beneficial effect of psilocybin on behavioral despair and cognitive impairment. Biochemical analyses revealed psilocybin-induced increases in thyroid-stimulating hormone (TSH) levels without significant changes in the hypothalamic-pituitary-adrenal (HPA) axis. The ability of psilocybin to counter stress-induced TSH reductions suggested that TSH may serve as a proxy marker of therapeutic response, although its causal role in mood regulation remains unclear. Additionally, following psilocybin administration, changes in cannabinoid receptor type I (CB1R) suggest a potential modulation of psilocybin intervention on the component of the endocannabinoid system (ECS), though causal links remain unconfirmed without antagonist studies. These findings highlight the potential of psilocybin to treat TRD through the targeting of previously unexplored biological pathways.

Neural Response to Reward and Loss Following Basic Combat Training

BACKGROUND

The brain's responsiveness to rewarding stimuli is essential for adaptive functioning while deficits in neural reward processing have been linked to the transdiagnostic symptom of anhedonia. Acute or prolonged stressors may negatively impact neural reward responses; however, few studies have examined if real-world naturalistic stressors prospectively predict reductions in brain responses to rewards.

METHODS

This pre-registered analysis (https://osf.io/f6e8w) used data from the ARMOR study to assess whether exposure to basic combat training (BCT), a demanding and stress-inducing 10-week program, led to reductions in electrophysiological measures of reward response. One hundred sixteen military recruits completed a virtual gambling task while electroencephalogram (EEG) was recorded before and after BCT. Mean EEG activity in the time window of the Reward Positivity (RewP; 175 - 325ms post-feedback at FCz) was averaged separately for the gain and loss condition.

RESULTS

We found that neural response to both gain and loss feedback in the time-window of the RewP significantly decreased from baseline following BCT (b = -0.67, p <.001), but the difference between conditions did not (b = 0.28, p = .23). Greater reports of BCT-related stressors predicted decreased neural response to gain, but not loss. Finally, baseline reward-related power in the delta-band frequency prospectively predicted less self-reported BCT-related stress.

CONCLUSIONS

These findings suggest that experiencing the stress of BCT is associated with reductions in neural processing of both reward and loss feedback. Further, those with greater reward-related delta oscillatory activity may perceive less negative impact of real-world stressors.

Unveiling diverse clinical symptom patterns and neural activity profiles in major depressive disorder subtypes

BACKGROUND

The heterogeneity of major depressive disorder (MDD) significantly hinders its effective and optimal clinical outcomes. This study aimed to identify MDD subtypes by adopting a data-driven approach and assessing validity based on symptomatology and neuroimaging.

METHODS

A total of 259 patients with MDD and 92 healthy controls were enrolled in this cross-sectional study. Latent profile analysis (LPA) was used to identify MDD subtypes based on validated clinical symptoms. To examine whether there were differences between these identified MDD subtypes, network analysis was used to test any differences in symptom patterns between these subtypes. We also compared neural activity between these identified MDD subtypes and tested whether certain neural activities were related to individual subtypes. This MDD subtyping was further tested in an independent dataset that contains 86 patients with MDD.

FINDINGS

Five MDD subtypes with distinct depressive symptom patterns were identified using the LPA model, with the 5-class model selected as the optimal classification solution based on its superior fit indices (AIC = 6656.296, aBIC = 6681.030, entropy = 0.917, LMR p = 0.3267, BLRT p < 0.001). The identified subtypes include atypical-like depression, two melancholic depression (moderate and severe) subtypes with distinct patterns on feeling anxious, and two anhedonic depression subtypes (moderate and severe) with different manifestations on weight/appetite loss. The reproducibility of the classification was also confirmed. Significant differences in symptom structures between melancholic and two anhedonic subtypes, and between anhedonic and atypical subtypes were observed (all p < 0.05). Furthermore, these identified subtypes had differential neural activities in both regional spontaneous neural activity (pFWE < 0.005) and functional connectivity between different brain regions (pFDR < 0.005), linked to different clinical symptoms (FDR q < 0.05).

INTERPRETATION

The network analysis and neuroimaging tests support the existence and validity of the identified MDD subtypes, each exhibiting unique clinical manifestations and neural activity patterns. The categorisation of these subtypes sheds light on the heterogeneity of depression and suggest that personalised treatment and management strategies tailored to specific subtypes may enhance intervention strategies in clinical settings.

FUNDING

National Natural Science Foundation of China (NSFC) and China Scholarship Council (CSC).

Selective KOR antagonist alters functional patch sizes in individualized brain system: results from the Fast-fail Trial in Mood and Anxiety Spectrum Disorders (FAST-MAS)

In our prior study involving a transdiagnostic sample of individuals with anhedonia, we showed that an 8-week administration of a selective κ-opioid receptor (KOR) antagonist enhanced fMRI ventral striatal activation during reward anticipation in the Monetary Incentive Delay task as compared to a placebo. However, individual differences in brain architecture may limit the translation of this finding to the context of precision medicine. Here, we adopted an individual-specific approach to elucidate the effects of selective KOR antagonism on cortical-subcortical reward circuits in individuals with anhedonia. Sixty-four participants with anhedonia (30 KOR Antagonist, 34 Placebo) who completed both pre- and post- treatment MRI scans in the FAST-MAS study were included in this analysis. Using an individualized-brain-systems-functional-brain-mapping approach, functional networks were mapped at the individual level, and individual-specific cortical patches and subcortical-cortical clusters were obtained. Statistical analyses were conducted to examine the pre- and post-treatment changes in patch and cluster sizes, as well as their relationships with clinical-cognitive measures. ROI analyses revealed a significant patch size decrease in the right medial posterior prefrontal cortex within the frontoparietal control network, and significant size increases in three right subcortical clusters - pallidum, amygdala, and thalamus - within the orbitofrontal-limbic network, following KOR antagonist treatment. In short, we applied recently developed computational neuroimaging approaches to examine changes in the individualized brain systems of FAST-MAS participants before and after eight weeks of KOR antagonist treatment for anhedonia. Our results revealed alterations in functional cortical patch and subcortical-cortical cluster sizes in anhedonia-related brain regions following KOR antagonist treatment.

Ketamine rescues anhedonia by cell-type- and input-specific adaptations in the nucleus accumbens

Ketamine is recognized as a rapid and sustained antidepressant, particularly for major depression unresponsive to conventional treatments. Anhedonia is a common symptom of depression for which ketamine is highly efficacious, but the underlying circuits and synaptic changes are not well understood. Here, we show that the nucleus accumbens (NAc) is essential for ketamine's effect in rescuing anhedonia in mice subjected to chronic stress. Specifically, a single exposure to ketamine rescues stress-induced decreased strength of excitatory synapses on NAc-D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs). Using a cell-specific pharmacology method, we establish the necessity of this synaptic restoration for the sustained therapeutic effects of ketamine on anhedonia. Examining causal sufficiency, artificially increasing excitatory synaptic strength onto D1-MSNs recapitulates the behavioral amelioration induced by ketamine. Finally, we used opto- and chemogenetic approaches to determine the presynaptic origin of the relevant synapses, implicating monosynaptic inputs from the medial prefrontal cortex and ventral hippocampus.

Breaking through anhedonia: How ketamine reignites the drive for rewards

In this issue of Neuron, Pignatelli et al.1 find that ketamine reverses stress-induced changes in excitatory synapses in nucleus accumbens D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs) and that these changes are necessary for the treatment of anhedonia-like behavior.

The effect of adjunctive cariprazine on symptoms of anhedonia in patients with major depressive disorder

BACKGROUND

Anhedonia is a core diagnostic symptom of major depressive disorder (MDD). Post hoc analyses evaluated cariprazine plus antidepressant treatment (ADT) in patients with MDD and moderate-to-severe anhedonia.

METHODS

Data were analyzed from a positive phase 3, randomized, fixed-dose (1.5 or 3 mg/d), double-blind, placebo-controlled, parallel-group cariprazine study (NCT03738215). Post hoc outcomes (e.g., change from baseline to week 6 in MADRS total score, MADRS anhedonia subscale score, MADRS anhedonia subscale item scores including item 8 [inability to feel]) were assessed in 2 anhedonia patient subgroups (baseline MADRS anhedonia subscale score ≥ 18; baseline MADRS anhedonia item 8 score ≥ 4) using a mixed-effects model for repeated measures.

RESULTS

Most patients met subgroup inclusion criteria (anhedonia subscale score ≥ 18 = 584 [77.8 %]; anhedonia item 8 score ≥ 4 = 508 [67.6 %]). LSMDs in change from baseline were statistically significant in favor of adjunctive cariprazine versus adjunctive placebo in the MADRS anhedonia subscale score ≥ 18 subgroup (MADRS total score: 1.5 mg/d = -3.4, p = .0006; 3 mg/d = -2.1, p = .0358; anhedonia subscale score: 1.5 mg/d = -2.1, p = .0010; 3 mg/d = -1.26, p = .0399) and in the anhedonia item 8 score ≥ 4 subgroup for adjunctive cariprazine 1.5 mg/d (MADRS total score: -3.2, p = .0037; anhedonia subscale score: -1.9, p = .0066). Significant differences were seen for adjunctive cariprazine versus adjunctive placebo on several anhedonia subscale single items, including anhedonia item 8 for the 1.5 mg/d dose.

LIMITATION

Post hoc analysis.

CONCLUSION

In patients with MDD and moderate-to-severe anhedonia, adjunctive cariprazine improved symptoms of general depression and anhedonia, suggesting a potential benefit for patients with this clinically significant symptom.

Efficacy and Safety of Toludesvenlafaxine Hydrochloride Sustained-Release Tablets in Depression With Anhedonia: A Single-Arm, Multicenter Clinical Study

Toludesvenlafaxine hydrochloride sustained-release tablets, as China's first independently developed chemical Class 1 innovative drug with independent intellectual property rights for the treatment of depression and a new molecular entity, represent a novel triple reuptake inhibitor (TRI) with specific target selectivity for serotonin (5-HT), norepinephrine (NE), and dopamine (DA). This single-arm, multicenter clinical study aimed to evaluate the efficacy and safety of toludesvenlafaxine in alleviating anhedonia symptoms in patients with major depressive disorder (MDD). A total of 123 patients aged 18-65 years were enrolled between April 2023 and April 2024 and received an 8-week treatment with toludesvenlafaxine sustained-release tablets (80-160 mg/day). The primary efficacy endpoint was the change in the total score of the Dimensional Anhedonia Rating Scale (DARS) at weeks 2, 4, and 8. Significant improvements in DARS scores were observed, with mean changes from baseline of 8.4 (95% CI [6.4, 10.4], p < 0.0001), 14.1 (95% CI [12.0, 16.2], p < 0.0001), and 20.4 (95% CI [18.0, 22.9], p < 0.0001), respectively. Additionally, after 8 weeks of treatment, plasma levels of neurotrophic factors, including mature brain-derived neurotrophic factor (mBDNF) (t = 28.78, p < 0.0001), pro-BDNF (t = 27.71, p < 0.0001), and vascular endothelial growth factor (VEGF) (t = 31.07, p < 0.0001), were significantly increased, and the plasma level of IGF-1 was not significantly changed (t = 0.35, p=0.7269). No association was found between the percentage of changes in neurotrophic factors and the percentage of symptom improvements. Toludesvenlafaxine was generally well-tolerated, with treatment-emergent adverse events (AEs) (TEAEs) reported in 83.7% of participants and treatment-related AEs (TRAEs) in 76.4%. These findings indicate that toludesvenlafaxine hydrochloride sustained-release tablets are safe, well-tolerated, and effective in alleviating anhedonia symptoms in patients with depression. Trial Registration: http://www.chictr.org.cn (No.: ChiCTR2300070331).

Severity of anhedonia is associated with hyper-synchronization of the salience-default mode network in non-clinical individuals: a resting state EEG connectivity study

Anhedonia is a core transnosographic symptom in several neuropsychiatric disorders. Recently, the Triple Network (TN) model has been proposed as a useful neurophysiological paradigm for conceptualizing anhedonia, providing new insights to clinicians and researchers. Despite this, the relationship between the functional dynamics of TN and the severity of anhedonia has been relatively understudied in non-clinical samples, especially in the resting state (RS) condition. Therefore, in the current study, we investigated this relationship using electroencephalography (EEG) functional connectivity. Eighty-two participants (36 males; mean age: 24.28 ± 7.35 years) underwent RS EEG recording with eyes-closed and completed the Beck Depression Inventory-derived 4-item anhedonia scale (BDI-Anh4) and the Brief Symptoms Inventory (BSI). EEG data on functional connectivity were analyzed using the exact low-resolution electromagnetic tomography (eLORETA). A significant positive correlation was observed between the BDI-Anh4 total score and salience-default mode network connectivity in the beta frequency band (r = 0.409; p = 0.010). The results of the hierarchical linear regression analysis also showed that this connectivity pattern was positively and independently associated (β = 0.358; p < 0.001) with the BDI-Anh4 total score and explained an additional 11% of the anhedonia variability. The association between anhedonia severity and increased salience-default mode network synchronization detected in the current study may reflect difficulty disengaging from internal/self-related mental contents, which consequently impairs the processing of other stimuli, including rewarding stimuli.

Eupalinolide B alleviates corticosterone-induced PC12 cell injury and improves depression-like behaviors in CUMS rats by regulating the GSK-3β/β-catenin pathway

Eupalinolide B (EB), a primary bioactive compound isolated from Eupatorium lindleyanum DC., has exhibited various pharmacological properties, such as antitumor, anti-inflammatory, and notably, neuroprotective effects in neurodegenerative diseases. However, the in-depth studies on the antidepressant potential of EB and its underlying mechanisms are still lacking. Herein, we investigated the therapeutic effects of EB on corticosterone (CORT)-induced neurotoxicity in PC12 cells and its antidepressant-like effects in rats subjected to chronic unpredictable mild stress (CUMS). In particular, we focused on the molecular mechanisms related to modulating the GSK-3β/β-catenin pathway. Our findings revealed that EB promoted cell proliferation while decreasing apoptosis and oxidative stress in CORT-induced PC12 cells. In vivo, EB alleviated the depressive-like behaviors in CUMS rats, as assayed by the sucrose preference test, open field test, and forced swim test. Additionally, EB attenuated the hippocampal pathological damage and increased Ki67- and doublecortin-positive cell numbers in hippocampal dentate gyrus, thus restoring hippocampal neurogenesis in CUMS rats. The binding of EB to GSK-3β was confirmed using molecular docking and cellular thermal shift assays. Overexpression of GSK-3β diminished the therapeutic effects of EB on CORT-induced PC12 cells, further indicating that GSK-3β is the target of EB. Mechanistically, EB hindered GSK-3β activity and thus activated β-catenin signaling in both CORT-induced PC12 cells and CUMS rat hippocampus, as demonstrated by increased p-GSK-3β (Ser9), reduced p-β-catenin, and elevated β-catenin expression. Collectively, this study offers new insights into the antidepressant mechanisms of EB, highlighting its potential as a candidate for depression treatment.

Reward System EEG-fMRI-Pattern Neurofeedback for Major Depressive Disorder with Anhedonia: A Multicenter Pilot Study

Background/Objectives: Up to 75% of patients with major depressive disorder (MDD) exhibit persistent anhedonia symptoms related to abnormalities in the positive valence system. Cumulative evidence points to brain dysfunction in the reward system (RS), including in the ventral striatum, in patients with MDD with anhedonia. This study aims to evaluate the safety and efficacy of a novel neurofeedback (NF) device (termed Prism) which incorporates the EEG-FRI-Pattern biomarker of the reward system (RS-EFP) for use in self-neuromodulation training (RS-EFP-NF) for alleviating depression in patients with MDD with anhedonia. Methods: A total of 49 adults (age range: M = 39.9 ± 11.03) with a DSM-5 diagnosis of MDD with anhedonia (per a SHAPS-C score ≥ 25) were screened for the administration of ten sessions of RS-EFP-NF twice a week on nonconsecutive days. Depression and anhedonia severity was assessed, respectively, by HDRS-17 and SHAPS-C at baseline, midway, and treatment end. Results: A total of 34 patients (77%) completed the protocol and were included in the analyses. No device-related adverse events were serious or required treatment. Depression symptoms were reduced at end of treatment as indicated by the HDRS-17, with a reduction of eight points on average (95% CI: -10.5 to -5.41, p < 0.0001), a clinical improvement rate of 78.47%, and a remission rate of 32.25%. Anhedonia, as indicated by the SHAPS-C score, was diminished, showing an average reduction of 6.3 points (95% CI: -8.51 to -4.14, p < 0.0001). Conclusions: Self-neuromodulation using RS-EFP-NF is a promising and safe treatment for MDD with anhedonia. The intervention demonstrates substantial clinical effects on both depression and anhedonia symptoms, with high patient acceptability and retention. Prism may address a critical mechanism-driven treatment gap for anhedonia that often persists despite conventional therapies. Larger controlled implementation, efficacy, and dosing studies are warranted.

Quantitative scale validation of the Dimensional Anhedonia Rating Scale in the treatment of Chinese patients with major depressive disorder

Background

The patient-reported Dimensional Anhedonia Rating Scale (DARS) has been adapted into Chinese, so there is a need to evaluate its measurement properties in a Chinese population.

Aims

To evaluate the reliability and validity of the DARS among Chinese individuals with major depressive disorder (MDD) and its treatment sensitivity in a prospective clinical study.

Methods

Data were from a multicentre, prospective clinical study (NCT03294525), which recruited both patients with MDD, who were followed for 8 weeks, and healthy controls (HCs), assessed at baseline only. The analysis included confirmatory factor analysis, validity and sensitivity to change.

Results

Patients' mean (standard deviation (SD)) age was 34.8 (11.0) years, with 68.7% being female. 75.2% of patients with MDD had melancholic features, followed by 63.8% with anxious distress. Patients had experienced MDD for a mean (SD) of 9.2 (18) months. DARS scores covered the full range of severity with no major floor or ceiling effects. Confirmatory factor analysis showed adequate fit statistics (comparative fit index 0.976, goodness-of-fit index 0.935 and root mean square error of approximation 0.055). Convergent validity with anhedonia-related measures was confirmed. While the correlation between the DARS and the Hamilton Depression Rating Scale was not strong (r=0.31, baseline), the DARS was found to differentiate between levels of depression. Greater improvements in DARS scores were seen with the Hamilton Rating Scale for Depression responder group (effect size 1.16) compared with the non-responder group (effect size 0.46).

Conclusions

This study comprehensively evaluated the measurement properties of the DARS using a Chinese population with MDD. Overall, the Chinese version of DARS demonstrates good psychometric properties and has been found to be responsive to change during antidepressant treatment. The DARS is a suitable scale for assessing patient-reported anhedonia in future clinical trials.

Anhedonia relates to reduced striatal reward anticipation in depression but not in schizophrenia or bipolar disorder: A transdiagnostic study

Anhedonia, i.e., the loss of pleasure or lack of reactivity to reward, is a core symptom of major psychiatric conditions. Altered reward processing in the striatum has been observed across mood and psychotic disorders, but whether anhedonia transdiagnostically contributes to these deficits remains unclear. We investigated associations between self-reported anhedonia and neural activation during reward anticipation and consumption across patients with schizophrenia (SZ), bipolar disorder (BD), major depressive disorder (MD), and healthy controls (HC). Using the Monetary Incentive Delay paradigm, we acquired functional magnetic resonance imaging data sets in 227 participants (18-65 years), including patients with SZ (n = 44), BD (n = 47), MD (n = 56), and HC (n = 80). To capture anhedonia, three items of the Symptom Checklist-90-R were entered into exploratory factor analysis, which resulted in a single anhedonia factor. Associations between anhedonia and neural activation were assessed within a striatal region-of-interest and exploratorily across the whole brain (pFWE < .05). Self-reported anhedonia was high in MD, low in HC, and intermediate in SZ and BD. During reward anticipation, anhedonia correlated with reduced striatal activation; however, the correlation depended on diagnostic group. Specifically, the effect was driven by a negative relationship between anhedonia and dorsal striatal (putamen) activity within the MD group; for reward consumption, no correlations were found. Our results indicate that anticipatory anhedonia in MD may relate to reduced behavioral motivation via disrupted encoding of motor plans in the dorsal striatum. Future transdiagnostic research should stratify participants by anhedonia levels to achieve more homogeneous samples in terms of underlying neurobiology.

Restorative properties of chronic lurasidone treatment on emotional dysfunction in rats exposed to chronic unavoidable stress: A role for medial prefrontal cortex - nucleus accumbens network

Anhedonia, a transdiagnostic symptom prevalent in depressive and psychotic disorders, poses a significant challenge for pharmacological intervention due to its association with impaired motivation. Understanding how psychotropic drugs can modulate this pathological domain and elucidating the molecular mechanisms underlying such effects are crucial endeavors in psychiatric research. In this study, we aimed to investigate the pro-motivational properties of lurasidone in a rat (Sprague Dawley males) model of anhedonia and to unravel the interplay between lurasidone and the brain regions critical for reward processing. Exposure to unpredictable chronic stress (UCS) led to a marked reduction in motivation, a deficit that was restored by lurasidone treatment at 3 mg/kg, but not at 10 mg/kg. Interestingly, the stress-induced decrease in reactivity to negative stimuli was reversed by both doses of lurasidone. At the molecular level, stressed animals exhibited reduced expression of neuroplastic markers, that was increased following lurasidone administration. Furthermore, UCS exposure impaired the activation of the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) in response to hedonic stimuli, an effect amended by lurasidone treatment. Additionally, lurasidone restored the impaired phosphorylation of DARPP-32, a key regulator of dopamine signaling, in mPFC and NAc of UCS rats exposed to a hedonic stimulus. These findings underscore the potential of lurasidone in improving various psychopathological domains, like impaired motivation and emotional reactivity, core elements contributing to the disability associated with mental disorders. These effects highlight the therapeutic potential of lurasidone in addressing the intricate behavioral and neurochemical alterations associated with anhedonia and related mood disorders.

The neurobiology of motivational anhedonia in patients with depression

Anhedonia is a core feature of depression. It contains a consummatory and a motivational aspect. Whilst much neuroimaging research in patients with depression focused on the consummatory aspect of anhedonia, less is known about its motivational aspect. This study aimed to explore the neurobiology of networks related to motivational anhedonia. Thirty-eight patients with major depressive disorder (MDD) and 19 healthy controls underwent diffusion-weighted and resting state functional magnetic resonance imaging (rs-fMRI). For assessment of motivational anhedonia, we summed the values of the CORE non-interactiveness score, and the items 1 (hopelessness) and 7 (work and activities) of the Hamilton Depression Rating Scale. Whole-brain voxel-wise statistical analysis of fractional anisotropy (FA) data was performed using Tract-Based Spatial Statistics (TBSS). Additionally, we performed a whole-brain comparison of integrated local correlation of rs-fMRI signal (LCOR), to investigate regional functional differences between patients and healthy controls. Whole brain correlations between motivational anhedonia and measures of structural and functional connectivity (FA, and LCOR) were calculated. TBSS-analyses revealed reduced FA in the left superior longitudinal fasciculus (SLF) in patients with MDD. LCOR was reduced in patients with depression in an adjacent cluster localized in bilateral precunei. Within patients, there was a positive correlation between motivational anhedonia and LCOR in the precunei and a negative correlation in bilateral sensorimotor areas. FA-values did not show significant correlations. These findings suggest that motivational anhedonia in depression is linked to alterations of functional connectivity within bilateral precunei. Observed white matter microstructural alterations in the SLF do not show such an association.

Network analysis of central symptoms in Chinese young adults with subthreshold depression

Subthreshold depression (SD) is a prevalent condition among young adults, significantly increasing the risk of developing major depressive disorder (MDD). While the symptoms of MDD are well-documented, the network structure and key symptoms of SD, which forms a complex, interdependent system, have not been fully elucidated. This study sought to identify the central symptoms and their interconnections within the depressive symptom network in young adults with SD. A total of 834 Chinese young adults with SD completed the 21-item Beck Depression Inventory 2nd version (BDI-II) and were included in this study. Network analysis was employed to identify central symptoms (nodes) and associations between symptoms (edges) as assessed by the BDI-II. Additionally, centrality indicators for network robustness underwent assessment through stability and accuracy tests. The analysis revealed that Loss of interest was the most central node in the SD symptom network, with Tiredness/fatigue and Agitation following closely. Significant associations were observed between Loss of energy and Concentration difficulties, Agitation and Irritability, Guilty feelings and Self-dislike, as well as Tiredness and Loss of pleasure. The network demonstrated robustness across stability and accuracy assessments. Loss of interest, Tiredness/fatigue, and Agitation were pivotal symptoms within the depressive symptom network of SD in young adults. These symptoms may serve as critical targets for therapeutic interventions and should be prioritized in future psychological and neurobiological research to advance our understanding of SD.

The characteristics of anhedonia in depression: a review from a clinically oriented perspective

Anhedonia, as one of the core symptoms of major depressive disorder (MDD), has been regarded as a potential endophenotype of the disease. Multiple studies have evaluated the potential mechanisms of anhedonia in MDD, and found that MDD patients with anhedonia showed different functions in clinical features. In this review, we focus on the clinical research to explore the differences between MDD patients with and without anhedonia in the clinical manifestations and biological alterations, and elaborate the treatments and prognosis of anhedonia. It is demonstrated that anhedonia is associated with adverse outcomes including more severe depressive episode and suicidality, and poor prognosis in patients with MDD. At the biological level, MDD patients with anhedonia seem to present higher levels of inflammatory factors, abnormal metabolic function and hypermetabolism of BDNF. In brain imaging studies, there are some structural and/ or functional changes in multiple brain regions of subcortical and cortical areas, as well as the limbic system in MDD patients with anhedonia. Meanwhile, preliminary research findings have also indicated that there are associations between intestinal flora imbalance and anhedonia. Moreover, evidence indicated the benefit of some selective serotonin reuptake inhibitors seemed limited on anhedonia, and other treatments including psychotherapy, physical therapy and probiotic interventions has remained to be explored but has interesting potential. Therefore, increased awareness of the anhedonic symptoms and the unique clinical features would benefit improved early diagnosis and therapeutic effects in MDD.

Sex differences in oscillatory signaling dynamics in the prelimbic cortex and nucleus accumbens core during negative affect

Affective processing is important for guiding behavior and its dysfunction can lead to several psychiatric illnesses, including depression and substance use disorders. Conditioned taste aversion (CTA) is used to study learned shifts in affect, and taste reactivity (TR) can effectively track the hedonic properties of appetitive and aversive tastants before and after CTA. While the infralimbic cortex (IL) and its projections to the nucleus accumbens (NAc) shell play a key role in learned negative affect, this role is unique to males. Here, we sought to determine if the prelimbic cortex (PrL) to nucleus accumbens (NAc) core circuit, another prefrontal cortex-accumbens system, tracks innate versus learned negative affect using electrophysiological (local field potential, LFP) methods in male and female rats. As expected, CTA elicited a hedonic shift from an appetitive to an aversive TR profile, regardless of sex. However, time-frequency analyses revealed differential activity in the PrL and NAc core during innate and learned negative affect across sex. Specifically, we found that beta oscillations in the NAc core encode learned negative affect in males, while neither brain region seems to be selectively attuned to innate or learned aversion in females. Importantly, LFP functional connectivity (coherence) indicated that the PrL-NAc core circuit does not track any aspect of learned negative affect in either sex but may be involved in innate aversion in males only. Collectively, these data provide a sex-specific understanding of real-time oscillatory signaling dynamics in the PrL and NAc core during innate versus learned negative affect.

Anhedonia: Current and future treatments

Anhedonia is a transdiagnostic domain that leads to poor disorder outcome and low remission rates. This narrative review describes a broad range of interventions targeting anhedonia, including pharmacological, neuromodulatory, behavioral, and lifestyle-based approaches. Drugs such as vortioxetine, agomelatine, bupropion, ketamine, and brexpiprazole show promising anti-anhedonic effects, while traditional antidepressants, such as serotonin-norepinephrine reuptake inhibitors (SNRIs) and, even more so, selective serotonin reuptake inhibitors (SSRIs), are less effective. Neuromodulation techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and transcutaneous auricular vagus nerve stimulation, proved effective at improving anhedonia, particularly when used in targeted areas. Psychotherapeutic interventions, including behavioral activation, mindfulness-based strategies, and savoring techniques, also help re-engage patients with pleasurable activities and enhance positive affect. Innovative treatments, such as aticaprant and psilocybin, showed promising results. Substantial evidence suggests that improving anhedonia leads to better psychosocial functioning, quality of life, and sustained remission. Although most data come from short-term studies, several long-term analyses suggest that maintaining hedonic improvements is feasible and beneficial. The reviewed evidence underscores the importance of routine assessment of anhedonia and the integration of symptom-specific strategies. Tailoring interventions to address individual patterns of reward disruption may optimize outcomes for patients with anhedonia.

Illuminating the impact of stress: In vivo approaches to track stress-related neural adaptations

Stressful experiences can affect both daily life and long-term health outcomes in a variety of ways. Acute challenges may be adaptive, promoting arousal and enhancing memory and cognitive function. Importantly, however, chronic stress dysregulates the body's physiological regulatory mechanisms consisting of complex hormone interactions throughout the peripheral and central nervous systems. This disrupted signaling consequently alters the balance of synapse formation, maturation and pruning, processes which regulate neural communication, plasticity, learning, cognitive flexibility and adaptive behaviors - hallmarks of a healthy, functional brain. The chronically stressed brain state, therefore, is one which may be uniquely vulnerable. To understand the development of this state, how it is sustained and how behavior and neural function are transiently or indelibly impacted by it, we can turn to a number of advanced approaches in animal models which offer unprecedented insights. This has been the aim of my recent work within the field and the goal of my new independent research program. To achieve this, I have employed methods to uncover how key brain circuits integrate information to support motivated behaviors, how stress impacts their ability to perform this process and how best to operationalize behavioral readouts. Here I present an overview of research contributions that I find most meaningful for advancing our understanding of the impact of stress and propose new avenues which will guide my own framework to address the salient outstanding questions within the field.

Cognitive effects of early life exposure to PCBs in rats: Sex-specific behavioral, hormonal and neuromolecular mechanisms involving the brain dopamine system

Endocrine-disrupting chemicals (EDCs) are environmental toxicants that disrupt hormonal and neurodevelopmental processes. Among these chemicals, polychlorinated biphenyls (PCBs) are particularly concerning due to their resistance to biodegradation and tendency to bioaccumulate. PCBs affect neurodevelopmental function and disrupt the brain's dopamine (DA) system, which is crucial for attentional, affective, and reward processing. These disruptions may contribute to the rising prevalence of DA-mediated neuropsychiatric disorders such as ADHD, depression, and substance use disorders. Notably, these behaviors are sexually dimorphic in part due to differences in sex hormones and their receptors, which are targets of estrogenic PCBs. Therefore, this study determined effects of early life PCB exposure on behaviors and neurochemistry related to potential disruption of dopaminergic signaling. Male and female Sprague Dawley rats were exposed to the PCB mixture Aroclor 1221 (A1221) or vehicle perinatally and then underwent a series of behavioral tests in adulthood, including the sucrose preference test to measure anhedonia, conditioned orienting to assess incentive-motivational phenotype, and attentional set-shifting to evaluate cognitive flexibility and response latency. Following these tests, rats were euthanized, and serum estradiol (E2), DA cells in the midbrain ventral tegmental area (VTA) and substantia nigra (SN), and gene expression from those combined midbrain nuclei were measured. Female rats exposed perinatally to A1221 exhibited decreased sucrose preference, and both male and female A1221 rats had reduced response latency in the attentional set-shifting task compared to vehicle counterparts. Conditioned orienting and serum estradiol (E2)were not affected in either sex; however, A1221-exposed rats of both sexes displayed higher TH+ cell numbers in the VTA and increased expression of dopamine receptor 1 (Drd1) in the combined midbrain nuclei. Additionally, E2 uniquely predicted behavioral outcomes and VTA DAergic cell numbers in A1221-exposed female rats, whereas DA signaling genes were predictive of behavioral outcomes in males. These data highlight sex-specific effects of A1221 on neuromolecular and behavioral phenotypes.

Investigating the role of mental imagery use in the assessment of anhedonia

Anhedonia, or a deficit in the liking, wanting, and seeking of rewards, is typically assessed via self-reported "in-the-moment" emotional and motivational responses to reward stimuli and activities. Given that mental imagery is known to evoke emotion and motivational responses, we conducted two studies to investigate the relationship between mental imagery use and self-reported anhedonia. Using a novel Reward Response Scale (adapted from the Dimensional Anhedonia Rating Scale, DARS; Rizvi et al., 2015) modified to assess deliberate and spontaneous mental imagery use, Study 1 (N = 394) compared uninstructed and instructed mental imagery use, and Study 2 (N = 586) conducted a test of replication of uninstructed mental imagery use. Results showed that greater mental imagery use was associated with higher reward response scores (Study 1 & 2), and this relationship was not moderated by whether imagery use was uninstructed or instructed (Study 1). Importantly, mental imagery use moderated the convergence between reward response and depression scale measures of anhedonia, with lower convergence for those reporting higher mental imagery use (Study 1 & 2). Results suggest that higher spontaneous mental imagery use may increase self-reported reward response and reduce the convergence between reward response scale and depression questionnaire measures of anhedonia. [199 / 200 words].

Scenting the Hedonic Connection: Exploring the Impact of Subjective Olfactory Dysfunction on Depressive Symptoms

Olfaction, often regarded as a unique chemical sensation, plays a pivotal role in shaping our quality of life and mental well-being. Numerous studies have highlighted the significant relationship between olfactory function and depressive symptoms. However, the complex mechanisms underlying how olfactory function affects the development of depressive symptoms remain largely unclear. In this study, we investigated the role of hedonic capacity in the link between olfactory function and depressive symptoms. We recruited 1661 young adults, along with an additional 381 participants who had experienced COVID-19-related olfactory dysfunction, to complete a series of self-report questionnaires assessing depressive symptoms, olfactory dysfunction, and hedonic capacity. A subset of 327 participants completed a follow-up survey 3 months later. Our sequential mediation analyses revealed that olfactory function indirectly influenced depressive symptoms through chemosensory pleasure. Moreover, it impacted pleasure derived from social activities by modulating chemosensory pleasure. Notably, this mediating effect persisted over the 3-month period and was evident even in participants with hyposmia, highlighting the lasting importance of chemosensory hedonic capacity. These findings suggest that both chemosensory and social hedonic capacities are crucial in the complex relationship between olfactory function and depressive symptoms. This insight not only deepens our understanding of the developmental psychopathology of depression but also offers a new perspective for its prevention.

Network of depression and anxiety symptoms in Chinese middle-aged and older people and its relationship with family health

OBJECTIVE

To examine the network structure of depression and anxiety symptoms and their association with Family Health among middle-aged and older people in China.

METHOD

This was a quantitative cross-sectional study, a total of 3,365 middle-aged and older people over 45 years were recruited, comprising 1,748 males and 1,617 females. Data were collected by using Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7, and the Short Form of the Family Health Scale.

RESULTS

The network structure of anxiety and depression symptoms was stable, and "Fatigue" and "Restlessness" were central symptoms and bridge symptoms. "Family, social or emotional health process" and "Family Healthy Lifestyle" exhibited a significant positive correlation, whereas "Family health resources" and "Suicide" demonstrated a significant negative correlation.

CONCLUSION

"Fatigue" and "Restlessness" are the targeted symptoms for preventing comorbid depression and anxiety symptoms among middle-aged and older adults, and the enhancement of "Family health resources" could be crucial for averting the onset of depression and anxiety symptoms within this demographic group.

Anhedonia and impulsivity in college alcohol use: A path analysis

OBJECTIVE

Alcohol use is a substantial problem among college students and has several negative consequences. The current study examined the associations between anhedonia and alcohol use and related problems via impulsive behavior (e.g., negative urgency, sensation seeking). We parsed anhedonia into four specific facets: consummatory, anticipatory, recreational, and social anhedonia.

PARTICIPANTS

Six hundred and forty college students aged 18-25 were included in the final analysis.

METHOD

Data were collected via Amazon Mechanical Turk. Self-report inventories assessing for anhedonia, alcohol use, impulsive behavior, and depressed mood were utilized.

RESULTS

Recreational consummatory anhedonia was negatively associated with alcohol use and alcohol-related problems through negative urgency. Recreational consummatory anhedonia also had significant negative associations with alcohol consumption via sensation seeking. Further, social anticipatory anhedonia was positively associated with alcohol use and related problems via negative urgency.

CONCLUSIONS

This study highlights important associations between anhedonia, impulsivity, and alcohol use and related problems.

Unilateral and Bilateral Subthalamic Deep Brain Stimulation Differently Favour Apathy in Parkinson's Disease

The link between subthalamic nucleus deep brain stimulation (STN-DBS) and apathy in patients with Parkinson's disease (PD) remains a controversial topic. The literature is mixed and the most supported explanation is the reduction of dopaminergic treatment. Yet a body of clinical and experimental evidences suggest that STN-DBS itself can also promote apathy in certain patients. However, the parameters accounting for apathy heterogeneity in stimulated patients along with the mechanisms underlying apathy induced by STN-DBS remain to be investigated. Whether bilateral and unilateral STN-DBS have the same influence on apathy is for instance unknown. We previously and separately showed in patients and rodents that bilateral STN-DBS can promote apathy per se. Here, we compare the effect of bilateral versus unilateral STN-DBS both in patients and in rodents. We conducted a clinical follow-up of patients with Parkinson's disease undergoing unilateral or bilateral STN-DBS and assessing apathy 3 months before and after STN-DBS. In parallel, we applied chronic and uninterrupted unilateral or bilateral DBS in rodents and extract longitudinal motivational changes with a battery of behavioural tests. While bilateral STN-DBS promotes apathy in patients and induces a loss of motivation in rodents, we found that unilateral STN-DBS did not exert such an effect both in patients and in rats. These data show that bilateral but not unilateral STN-DBS promotes apathy. This not only substantiate the induction of neuropsychiatric effects by STN-DBS but also suggest that this might be circumvented if STN-DBS is applied unilaterally instead of bilaterally.

The role of glucocorticoid and nicotinic acetylcholine receptors in the reward-enhancing effects of nicotine in the ICSS procedure in male and female rats

Tobacco use disorder is a chronic disorder that affects more than one billion people worldwide and causes the death of millions each year. The rewarding properties of nicotine are critical for the initiation of smoking. Previous research has shown that the activation of glucocorticoid receptors (GRs) plays a role in nicotine self-administration in rats. However, the role of GRs in the acute rewarding effects of nicotine are unknown. In this study, we investigated the effects of the GR antagonist mifepristone and the nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine on the reward-enhancing effects of nicotine using the intracranial self-stimulation (ICSS) procedure in adult male and female rats. The rats were prepared with ICSS electrodes in the medial forebrain bundle and then trained on the ICSS procedure. Nicotine lowered the brain reward thresholds and decreased response latencies similarly in male and female rats. These findings suggest that nicotine enhances the rewarding effects of ICSS and has stimulant properties. Treatment with the GR antagonist mifepristone did not affect the reward-enhancing effects of nicotine but increased response latencies, suggesting a sedative effect. Mecamylamine prevented the nicotine-induced decrease in brain reward thresholds and response latencies, but did not affect the brain reward thresholds or response latencies of the control rats. These findings suggest that the rewarding effects of nicotine are mediated via the activation of nAChRs, and that the activation of GRs does not contribute to the acute rewarding effects of nicotine. These studies enhance our understanding of the neurobiological mechanisms underlying tobacco use disorder.

Bridging animal models and humans: neuroimaging as intermediate phenotypes linking genetic or stress factors to anhedonia

BACKGROUND

Intermediate phenotypes, such as characteristic neuroimaging patterns, offer unique insights into the genetic and stress-related underpinnings of neuropsychiatric disorders like depression. This study aimed to identify neuroimaging intermediate phenotypes associated with depression, bridging etiological factors to behavioral manifestations and connecting insights from animal models to diverse clinical populations.

METHODS

We analyzed datasets from both rodents and humans. The rodent studies included a genetic model (P11 knockout) and an environmental stress model (chronic unpredictable mild stress), while the human data comprised 748 participants from three cohorts. Using the amplitude of low-frequency fluctuations, we identified neuroimaging patterns in rodent models. We then applied a machine-learning approach to cluster neuroimaging subtypes of depression. To assess the genetic predispositions and stress-related changes associated with these subtypes, we analyzed genotype and metabolite data. Linear regression was employed to determine which neuroimaging features predicted core depression symptoms across species.

RESULTS

The genetic and environmental stress models exhibited distinct neuroimaging patterns in subcortical and sensorimotor regions. Consistent patterns emerged in two neuroimaging subtypes identified across three independent depressed cohorts. The subtype resembling P11 knockout demonstrated higher genetic susceptibility, with enriched expression of risk genes in brain tissues and abnormal metabolites linked to tryptophan metabolism. In contrast, the stress animal-like subtype did not show changes in genetic risk scores but exhibited enriched risk gene expression in somatic and endocrine tissues, along with mitochondrial dysfunction in the antioxidant stress system. Notably, these distinct subcortical-sensorimotor neuroimaging patterns predicted anhedonia, a core symptom of depression, in both rodent models and depressed subtypes.

CONCLUSIONS

This cross-species validation suggests that these neuroimaging patterns may serve as robust intermediate phenotypes, linking etiology to anhedonia and facilitating the translation of findings from animal models to humans with depression and other psychiatric disorders.

Innate liking and disgust reactions elicited by intraoral capsaicin in male mice

Liking and disgust are the primary positive and negative emotions, respectively, and are crucial for nutrient intake and toxin avoidance. These emotions are induced by multimodal stimuli, such as taste, olfactory, and somatosensory inputs, and their dysregulation is evident in various psychiatric disorders. To understand the biological basis of liking and disgust, it is crucial to establish an animal model that allows for quantitative estimation of liking and disgust in response to multimodal stimuli. The only readout shared by many species, including humans, for liking and disgust, has been taste reactivity. However, readouts of non-taste stimuli-induced emotions remain unestablished. Here, we show that intraoral administration of capsaicin, a chemosomatosensory stimulus, elicits orofacial and bodily reactions in male mice similar to those observed in taste reactivity. Capsaicin-induced liking reactions at low concentrations and disgust reactions at high concentrations. Capsaicin-induced disgust reactions consisted of various reactions, including gape and forelimb flail, with the proportion of each reaction among the disgust reactions being similar to that induced by bitter and sour stimuli. These findings indicate that orofacial and bodily reactions, defined as taste reactivity, are elicited not only by taste stimuli but also by intraoral chemosomatosensory stimuli. Understanding the biological basis of capsaicin-induced orofacial and bodily reactions will advance our understanding of the fundamental mechanisms underlying liking and disgust across sensory modalities.

Early psilocybin intervention alleviates behavioral despair and cognitive impairment in stressed Wistar rats

Chronic stress exerts profound effects on mental health, contributing to disorders such as depression, anxiety, and cognitive impairment. This study examines the potential of psilocybin to alleviate behavioral despair and cognitive deficits in a rodent model of chronic stress, focusing on the interplay between the Hypothalamic-Pituitary-Adrenal (HPA) axis and the Endocannabinoid System (ECS). Twenty-two male Wistar rats were divided into control and stress groups. Animals within the stress group were exposed to predator odor and chronic social instability to induce chronic stress, and were either sham treated, or given psilocybin. Behavioral assessments were conducted using the Open Field Test, Sucrose Preference Test, Novel Object Recognition, Elevated Plus Maze, and Forced Swimming Test to evaluate locomotion, anhedonia, memory, anxiety, and behavioral despair, respectively. Blood and brain samples were analyzed for biochemical markers. Results indicated that psilocybin significantly reduced stress-induced behavioral despair and cognitive impairments, likely through ECS-mediated downregulation of the HPA axis. These findings suggest that early intervention with psilocybin has sustained beneficial effects on stress-related behavioral and cognitive disturbances, underscoring its potential as a novel therapeutic approach for stress-related mental health disorders.

Chronic stress induces depression through MDGA1-Neuroligin2 mediated suppression of inhibitory synapses in the lateral habenula

Rationale: The hyperactivity of lateral habenula (LHb) has been implicated in the pathophysiology of depression, but the regulatory mechanisms of inhibitory synapses in this context remains unclear. MDGA1 and neuroligin2 (Nlgn2), both regulators of inhibitory synapses, selectively interact in the LHb. We aimed to investigate if their interaction contributes to chronic restrained stress (CRS)-induced depression by modulating inhibitory synapses. Methods: Transgenic mouse models were established to conditional knockout/recover of MDGA1 expression or knockin Nlgn2 variant incapable of binding MDGA1 in the LHb, using viral Cre-recombinase expression. Synaptic function and density were assessed through electrophysiology and immunostaining, respectively. An acute restrained stress (ARS) model and chemogenetic activation of the lateral hypothalamus (LH) were used to stimulate the LHb. Behavioral tests related to depression were conducted following CRS. Results: MDGA1 and Nlgn2 selectively interacted in the LHb, which was elevated following CRS. Germline knockout of MDGA1 increased inhibitory transmission and GABAergic synapse density in the LHb, effects that were reversed by adult re-expression of MDGA1. Introduction of the Nlgn2 variant incapable of binding MDGA1 similarly enhanced inhibitory transmission and increased GABAergic synapse density in the LHb. Both germline MDGA1 deficiency and introduction of the Nlgn2 variant mitigated ARS- and LH activation-induced LHb neuron hyperactivation. MDGA1 deficiency in the LHb during adulthood increased inhibitory synaptic strength and conferred significant resistance to CRS-induced depressive behaviors, similar to the effects of introducing the Nlgn2 variant in the LHb. Conclusions: Our findings suggests that MDGA1-mediated suppression of Nlgn2 facilitates depression onset through limiting GABAergic synapse formation within the LHb. Targeting MDGA1/Nlgn2 complexes residing at GABAergic synapses within the lateral habenula may be viable for alleviating core behavioral symptoms of major depression.

Lower functional connectivity state transitions during affective processing correlate with subsequent impairment in sustaining positive affect in subthreshold depression

Background

Diminished capacity for maintaining positive affect (PA) has been identified in subthreshold depression (StD). While recent studies have explored affective dynamics among StD, the relationship between early emotional processing impairments and the capacity to prolong PA remains uncertain. Furthermore, it is unclear how brain connectivity patterns observed in StD are associated with PA maintenance.

Methods

The experimental procedure comprised a baseline rs-fMRI scan, followed by a PA-inducing movie viewing task, and three further rs-fMRI sessions. Participants provided PA ratings following each session. PA maintenance was quantified through the slope of mood change between each session after movie viewing. We performed a dynamic functional connectivity analysis on movie viewing data, as well as a series of static functional connectivity (FC), analyses on data of all rs-fMRI sessions from 25 StD and 25 healthy controls (HC). Correlations between brain-related measures and slope of mood change were calculated.

Results

Individuals with StD exhibited reduced capacity in sustaining PA, reflected in a decrease in PA in the early maintenance stage. StD also had a lower number of transitions between four brain states during movie viewing, which was related to subsequent impairment in sustaining PA. In addition, StD had weaker static FC between left inferior frontal gyrus and right middle occipital gyrus during the first resting-state session following movie viewing, which in turn was related to a steeper decline in PA.

Conclusions

These results highlight the brain features driving PA dysregulation in StD and provide a potential avenue for the development of future interventions.

Greater neural delay discounting on reward evaluation in anhedonia

Background/objective

Recent years have witnessed a surge of interest in dissecting the anticipatory and the consummatory aspects of anhedonia in terms of temporal dynamics. However, few research has directly examined reward valuation as a function of time in anhedonia.

Method

Using a delay discounting task, this event-related potential study examined the neural representation of rewards available immediately or in six months in a high-anhedonia group (N = 40) and a low-anhedonia group (N = 40) recruited from a nonclinical sample.

Results

We found that anhedonia was associated with greater neural delay discounting during reward evaluation. This was evidenced by a blunted effect of reward magnitude on the reward positivity (RewP) in the high-anhedonia compared to the low-anhedonia group when the rewards would be delivered six months later. Representation similarity analysis revealed that the aberration in processing delayed rewards is further corroborated by enhanced neural coding of reward time during the RewP period in the high-anhedonia versus low-anhedonia group.

Conclusions

These findings provide empirical evidence to show that anhedonia is driven by a blunted neural representation of future rewards instead of immediate rewards, suggesting an inability to form mental representations of future positive experiences in anhedonia.

The Potential Role of Dopamine Pathways in the Pathophysiology of Depression: Current Advances and Future Aspects

Depression is a serious mental health disorder that impacts more than 350 million individuals globally. While the roles of serotonin and norepinephrine in depression have been extensively studied, the importance of dopaminergic pathways-essential for mood, cognition, motor control, and endocrine function-often gets overlooked. This review focuses on four major dopamine (DA) circuits: the mesolimbic (MLP), mesocortical (MCP), nigrostriatal (NSP), and thalamictuberoinfundibular pathways (TTFP), and their roles in depression. The MLP, which is key to reward processing, is linked to anhedonia, a primary depression symptom. The MCP, projecting to the prefrontal cortex, affects cognitive issues like impaired attention and decision-making. The NSP, mainly responsible for motor control, is related to psychomotor retardation in depression, while the TTFP manages neuroendocrine responses, which are often disrupted in stress-related depressive conditions. Current antidepressant treatments mainly target serotonin and norepinephrine systems but tend to be less effective for patients with DArgic dysfunction, leading to treatment resistance. This review underscores emerging evidence that suggests targeting DArgic pathways could improve treatment outcomes, especially for symptoms like anhedonia and cognitive deficits that conventional therapies often fail to address. Future research should aim to combine advancements in neuroimaging, optogenetics, and genetic studies to better map DArgic pathways and create personalized treatment plans. This review highlights the potential for new therapies that focus on DA systems, which could pave the way for more effective and tailored approaches to treating depression.

Effect of Cariprazine on Anhedonia in Patients with Bipolar I Depression: Post Hoc Analysis of Three Randomized Placebo-Controlled Clinical Trials

INTRODUCTION

Anhedonic symptoms in bipolar I (BP-I) depression are associated with decreased quality of life and impaired functioning. We evaluated the effects of cariprazine in patients with BP-I depression with lower or higher levels of anhedonia at baseline.

METHODS

Data were pooled from three clinical trials (NCT01396447, NCT02670538, NCT02670551) analyzing the effects of cariprazine 1.5 and 3 mg/day in adults with BP-I depression. During post hoc analysis, patients were stratified by baseline median Montgomery-Åsberg Depression Rating Scale (MADRS) anhedonia factor score into a lower (score < median) or higher (score ≥ median) anhedonia subgroup. Outcomes included change from baseline to week 6 in MADRS total and anhedonia factor score, with the latter also evaluated after adjusting for other depressive symptoms. Between-group differences in change from baseline to week 6 were compared using least-squares mean differences (LSMD) analyzed via a mixed-effect model for repeated measures.

RESULTS

Median baseline anhedonia factor score was 19, defining the lower (placebo = 211; cariprazine 1.5 mg/day = 200, 3 mg/day = 212) and higher (placebo = 249; cariprazine 1.5 mg/day = 261, 3 mg/day = 250) anhedonia subgroups. In the lower subgroup, cariprazine 1.5 mg/day but not 3 mg/day was superior to placebo in reducing MADRS total (LSMD [95% CI] 1.5 mg/day = - 2.61 [- 4.28, - 0.93], P = .0024) and anhedonia factor scores (- 1.70 [- 2.77, - 0.62], P = .0021) at week 6. In the higher subgroup, both cariprazine doses were associated with significantly greater reductions than placebo in MADRS total (1.5 mg/day = - 3.01 [- 4.84, - 1.19], P = .0012; 3 mg/day = - 3.26 [- 5.12, - 1.40], P = .0006) and anhedonia factor scores (1.5 mg/day = - 1.97 [- 3.13, - 0.81], P = .0009; 3 mg/day = - 2.07 [- 3.26, - 0.89], P = .0006). Anti-anhedonic effects were preserved after adjusting for other depressive symptoms, suggesting the effect was not pseudospecific. Patients in the higher subgroup had higher baseline depression and therefore the lower subgroup may have had a floor effect.

CONCLUSION

Cariprazine demonstrated antidepressant and specific anti-anhedonic effects regardless of baseline anhedonia symptoms in patients with BP-I depression.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers, NCT02670538, NCT02670551, NCT01396447.

Brain functional effects of cognitive behavioral therapy for depression: A systematic review of task-based fMRI studies

BACKGROUND

Depressive disorders are associated with alterations in brain function, affecting processes such as affective and reward processing and emotion regulation. However, the influence of Cognitive Behavioral Therapy (CBT) on the neuronal patterns remains inadequately understood. Therefore, this review systematically summarizes longitudinal fMRI brain activity changes in depressive patients treated with CBT and their association with symptom remission.

METHODS

This systematic review was conducted according to the PRISMA statement. Out of 2149 results of the literature search, N = 14 studies met the inclusion criteria (e.g., diagnosis of a current depressive disorder, assessment of longitudinal task-based fMRI, and the analysis of functional changes before and after CBT).

RESULTS

The findings reveal (1) diminished limbic reactivity following CBT across various tasks, (2) increased striatal activity during reward processing, but decreased activity during affective processing and future thinking, and (3) alterations in cingulate and prefrontal cortex activity across tasks. Partially, these results are associated with symptom remission, especially in the subgenual anterior cingulate cortex.

LIMITATIONS

There are heterogenous results especially in cortical areas that might partially be due to methodological issues like differences across the studies in terms of task content, statistical evaluation, and interventions. Thus, future research should focus on the standardization of methodologies.

CONCLUSIONS

The results indicate that CBT partially normalizes the neural patterns of depressive patients, particularly within regions involved in affective and reward processing and the development of negative cognitive biases. Overall, potential neural mechanisms underlying CBT were identified, underscoring its effectiveness on an objective neurobiological basis.

Disrupted Maternal Behavior in Morphine-Dependent Pregnant Rats and Anhedonia in their Offspring

It is currently estimated that every 15 minutes an infant is born with opioid use disorder and undergoes intense early life trauma due to opioid withdrawal. Clinical research on the long-term consequences of gestational opioid exposure reports increased rates of social, conduct, and emotional disorders in these children. Here, we investigate the impact of perinatal opioid exposure (POE) on behaviors associated with anhedonia and stress in male and female Sprague Dawley rats. Young adult female rats were administered morphine via programmable, subcutaneous micro-infusion pumps before, during, and through one week post gestation. Maternal behavior was examined for fragmentation and entropy for the first two postnatal weeks; offspring were assessed for sucrose preference, social behavior, and stress responsivity. Overall, dams that received morphine across gestation displayed significantly less pup-directed behavior with increased fragmentation for nursing and higher entropy scores. In adolescence, male and female rat offspring exposed to morphine displayed reduced sucrose preference and, as adults, spent significantly less time socially interacting with familiar conspecifics. Changes in social behaviors were linked to increased activity in nondopaminergic mesolimbic reward brain regions. Although no treatment effects were observed in forced swim test performance, corticosterone levels were significantly increased in POE adult males. Together, these results suggest that perinatal morphine exposure results in anhedonic behavior, possibly due to fragmented and unpredictable maternal behavior in opioid-dependent dams.

How to improve reward sensitivity - Predictors of long-term effects of a randomized controlled online intervention trial

BACKGROUND

Reward sensitivity is a central maintaining factor of depression. Current treatments fail at sufficiently and reliably modifying reward processing. Therefore, we employed interventions targeting reward sensitivity and evaluated the long-term efficacy of different online interventions, additionally exploring predictors of changes in reward sensitivity.

METHODS

This four-arm randomized controlled trial (RCT) tested the long-term stability of treatment effects during a four-month follow-up in 127 participants of a two-week online intervention (behavioral activation vs. mindfulness and gratitude vs. combination of both). In addition, we investigated predictors of treatment success defined as improvement in reward sensitivity. Predictors we investigated were depressive expectations, stress and the type of reward implemented in the exercises of the intervention (physical activities and social encounters).

RESULTS

The improvement concerning reward sensitivity, as well as the reduction of anhedonia and depressive symptoms was stable over a four-month follow-up. We did not find evidence for differences between the active intervention groups. Positive changes in depressive expectations were a significant predictor of long-term improvements in reward sensitivity.

LIMITATIONS

Only self-report measures were used and the interpretation of the long-term efficacy of the online interventions is limited since the waitlist control condition was not extended to the follow-up.

CONCLUSIONS

Clinicians should focus on violating depressive expectations to facilitate updating the prediction and anticipation of future rewarding experiences. This could be a vital mechanism of change in reward sensitivity. However, future research still needs to unravel what kind of interventions are most effective in targeting reward insensitivity.

Neural and immune interactions linking early life stress and anhedonia

Early experiences of stress and adversity are associated with blunted reward sensitivity and altered reward learning. Meanwhile, anhedonia is characterized by impairments in reward processing, including motivation, effort, and pleasure. Early life stress (ELS) and anhedonia share psychological, behavioral, and neurobiological correlates, and the system-level interactions that give rise to anhedonia have yet to be fully appreciated. The proposed framework uses a multilevel, multisystem approach to aid in understanding neural-immune interactions that link ELS and anhedonia. The interactions linking anhedonia and ELS presented here include reduced reward sensitivity, alterations in hypothalamic-pituitary-adrenal (HPA) axis response, elevated inflammatory cytokines or physiological markers of stress, and blunted reward circuitry functioning along the mesocorticolimbic pathway. The clinical implications and areas for future research are also discussed. Ultimately, this research may inform the development of more specific and individualized treatments for anhedonia.

Anhedonia is associated with higher functional connectivity between the nucleus accumbens and paraventricular nucleus of thalamus

BACKGROUND

Anhedonia stands as a life-threatening transdiagnostic feature of many mental illnesses, most notably major depression and involves neural circuits for processing reward information. The paraventricular nucleus of the thalamus (PVT) is associated with reward-seeking behavior, however, links between the PVT circuit and anhedonia have not been investigated in humans.

METHODS

In a sample of adults with and without psychiatric symptoms (n = 75, 18-41 years, 55 female), we generated an anhedonia factor score for each participant using a latent factor analysis, utilizing data from depression and anxiety assessments. Functional connectivity between the PVT and the nucleus accumbens (NAc) was calculated from high-resolution (1.5 mm) resting state fMRI.

RESULTS

Anhedonia factor scores showed a positive relationship with functional connectivity between the PVT and the NAc, principally in males and in those with psychiatric symptoms. In males, connectivity between other midline thalamic nuclei and the NAc did not show these relationships, suggesting that this link may be specific to PVT.

LIMITATIONS

This cohort was originally recruited to study depression and not anhedonia per se. The distribution of male and female participants in our cohort was not equal. Partial acquisition in high-resolution fMRI scans restricted regions of interest outside of the thalamus and reward networks.

CONCLUSIONS

We report evidence that anhedonia is associated with enhanced functional connectivity between the PVT and the NAc, regions that are relevant to reward processing. These results offer clues as to the potential prevention and prevention and treatment of anhedonia.

Motives for nonmedical use of prescription stimulants in community college students

Objective: The present study identified common motives for nonmedical use of prescription stimulants (NMUS) among community college (CC) students and examined behavioral and demographic correlates of certain motives. Participants: The survey was completed by 3,113 CC students (72.4% female; 81.7% White). Methods: Survey results from 10 CCs were evaluated. Results: NMUS was reported by 9% (n = 269) participants. The most common motive for NMUS was to "focus on studies or to improve academic performance" (67.5%) followed by to "have more energy" (52.4%). Females were more likely to report NMUS for weight loss, and males were more likely to report NMUS to experiment. The motive "to feel good or get high" was linked to polysubstance use. Conclusions: CC students report similar motives for NMUS to those commonly endorsed by 4-year university students. These findings may help identify CC students susceptible to risky substance use.

The Pathologic Roles and Therapeutic Implications of Ghrelin/GHSR System in Mental Disorders

Ghrelin is a hormone consisting of 28 amino acids. Growth hormone secretagogue receptor (GHSR) is a receptor for ghrelin, which is expressed in the brain, pituitary gland, and adrenal glands, especially in the hypothalamus. The binding of ghrelin to the receptor 1a subtype mediates most of the biological effects of ghrelin. Ghrelin has a close relationship with the onset of psychosis. Ghrelin can affect the onset of psychosis by regulating neurotransmitters such as dopamine, γ-aminobutyric acid (GABA), and 5-hydroxytryptamine (5-HT) through the hypothalamus-pituitary-adrenal (HPA) axis, brain-gut axis, the mesolimbic dopamine system, and other ways. Ghrelin activates neuropeptide Y (NPY) in the hypothalamic arcuate nucleus (ARC) through the GHSR. Ghrelin binds to neurons in the ventral tegmental area (VTA), where it promotes the activity of dopamine neurons in the nucleus accumbens (NAcs) in a GHSR-dependent way, increasing dopamine levels and the reward system. This article summarized the recent research progress of ghrelin in depression, anxiety, schizophrenia, anorexia nervosa (AN), and bulimia nervosa (BN), and emphasized its potential application for psychiatric disorders treatment.

Sex-dependent effects of early life sensory overstimulation on later life behavioral function in rats

Children today are immersed in electronic technology shortly after birth as they now begin regularly watching television earlier than they did in the past. Many new programs geared towards infants contain lots of lights, color, and sounds, which may constitute a form of sensory overstimulation (SOS) that leads to cognitive and behavioral changes in children and adolescents. Here, we examined the impact of early life SOS exposure on later life behavioral and cognitive function in rodents by exposing developing male and female rats to excessive audiovisual stimulation from postnatal days (PND) 10-40 and assessing anxiety-like behavior, social motivation, compulsive behavior, and spatial learning/cognition from PND 50-60. To evaluate potential SOS effects on hypothalamic-pituitary-adrenal (HPA)-axis function, levels of the stress hormone corticosterone (CORT) were measured at 3 timepoints (e.g., PND 23, 41, 61) post-SOS exposure. Sensory overstimulated males exhibited reduced anxiety-like and compulsive behavior compared to controls, whereas females exhibited reduced social motivation but enhanced spatial learning/cognition compared to controls. No differences in baseline CORT levels were found at any age tested, suggesting no impact of early life SOS on later life basal HPA-axis function. Our results demonstrate sex-specific effects of early life SOS on distinct behavioral domains in early adult rats.

Prediction of anhedonia in patients with first-episode schizophrenia using a Wavelet-ALFF-based Support vector regression model

Anhedonia is one of the core features of the negative symptoms of schizophrenia and can be extremely burdensome. Our study applied resting-state functional magnetic resonance imaging (fMRI)-based support vector regression (SVR) to predict anhedonia in patients with first-episode schizophrenia (FES) and analysed the correlation between the wavelet-based amplitude low-frequency fluctuation (wavelet-ALFF) of the main brain region and anhedonia. We recruited 31 patients with FES and 33 healthy controls (HCs) from the Affiliated Brain Hospital of Guangzhou Medical University. All subjects completed the Temporal Experience of Pleasure Scale (TEPS) and received resting-state fMRI (rs-fMRI). We used the wavelet-ALFF method and SVR to analyse the data. Patients with FES had lower consummatory pleasure scores than healthy subjects (t = -2.71, P<0.01). FES displays variable wavelet-ALFF in a wide range of cerebral cortices (P<0.05, GFR corrected). The SVR analysis showed that wavelet-ALFF, based primarily on the right putamen (r = 0.40, P<0.05) and right superior occipital gyrus (r = -0.39, P<0.05), was effective in predicting consummatory pleasure scores with an accuracy of 56.43 %. Our study shows that abnormal spontaneous neural activity in FES may be related to the state of consummatory anhedonia in FES. Wavelet-ALFF changes in the right putamen and superior occipital gyrus may be a biological feature of FES with anhedonia and could serve as a potential biological marker of FES with anhedonia.

Prevalence of anhedonia, anxiety, and their impact on food consumption among postgraduate Qassim University students

Objectives

A prevalent symptom of many mental health issues, such as depression, is anhedonia, which is the inability to feel joy or pleasure. Tension-induced sensations, anxious thoughts, and bodily alterations are the hallmarks of anxiety. One known environmental factor that affects mental health is diet. In this implication, eating appetizing meals has been proposed to reduce unpleasant feelings like worry. This study aimed to indicate whether eating habits among postgraduate students are related to symptoms of anhedonia and/or anxiety.

Methods

In a cross-sectional study, responses were collected from a total of 393 postgraduate students. Each student self-answered the General Anxiety Disorder-7, Snaith-Hamilton Pleasure Scale for Anhedonia, and the Food Consumption Questionnaire and reported the body weight.

Results

The prevalence of anhedonia was 28%, moderate anxiety and severe anxiety were 15.7 and 10.9%, respectively. In this research, results showed that sugary foods, fast food, and fried foods were positively associated with anxiety and anhedonia. However, fruits and vegetables were negatively associated with anxiety and anhedonia. Linear regression showed that fruit and drinking water consumption was significant with the number of meals/day. There was no significance between the number of meals per day and anhedonia; however, there was statistical significance with the total GAD-7 scale score regarding the number of meals/per day.

Conclusion

Anhedonia and anxiety are associated with food consumption, especially foods rich in sugars, fast and fried, which help to increase positive feelings. Future studies should focus on understanding the relationship between food consumption and following a healthy diet and improving and reducing symptoms of anxiety and anhedonia in those who suffer from a stressful or task-filled lifestyle, such as students, especially postgraduate students. In addition, it focuses on the importance of awareness of the symptoms of anhedonia, which is classified as a depressive disease, and how to control anxiety to maintain better mental health.