Anhedonia Wiki

A living synthesis mined nightly by VaultMiner. Domain: Anhedonia research: the loss of pleasure and blunted reward, its measurement, biology and treatment, including where it crosses hormones (testosterone, menopause) and where standard antidepressants fall short.

Last updated: 2026-08-11

Anhedonia in Depression

• Anhedonia is a core symptom of major depressive disorder (MDD) and is linked to blunted reward processing. It is a key driver of other symptoms within the network of depressive symptoms, loneliness, and social media addiction among Chinese medical students. (source: bian-2026-a-network-analysis-of-depressive-symptoms-loneliness-and.md)
• Major depressive disorder (MDD) shows persistent anhedonic dysregulation of positive social emotion processing. Despite medicated patients having proper evaluation of sociality and stabilized limbic responses, their positive social responsiveness, top-down upregulation, and appraisal efficacy remain deficient. (source: bezmaternykh-2026-persistent-anhedonic-dysregulation-of-positive-social-emotion.md)
• Within-person anhedonia predicted greater next-week loneliness in a clinical sample, suggesting anhedonia may decrease motivation for social activities. (source: bautista-2026-the-dynamics-of-loneliness-longitudinal-associations-of-anhedonia.md)
• In co-occurring social anxiety and depression, anhedonia, boredom, and loneliness each uniquely partly accounted for the association, with boredom accounting for the largest proportion; anhedonia was associated with the link only among remote learners during the COVID-19 pandemic. (source: hager-2026-reward-deficits-in-co-occurring-social-anxiety-and-depression.md)
• In patients with epilepsy, anhedonia is one of the strongest connections between stigma and depression in a network analysis, alongside feelings of worthlessness and depressed mood. (source: gan-2026-the-relationship-between-depression-and-felt-stigma-in.md)
• Anhedonia and social anxiety are stable predictors of functional impairment, independent of motivational factors like behavioral inhibition and behavioral activation. (source: gallagher-2026-examining-the-independent-effects-of-motivational-factors-and.md)
• Among Palestinian refugees in Egypt, anhedonia is a central symptom in the female network of anxiety, depression, and PTSD, with the strongest cross-diagnostic association between trouble relaxing and anhedonia. (source: fadl-2026-anxiety-depression-and-post-traumatic-stress-disorder-among-palestinia.md)
• In a nationally representative U.S. sample and a daily diary study, anhedonia showed robust associations with functional impairment in both lifetime and daily contexts among young adults, alongside fatigue, appetite/weight disturbance, and guilt. (source: liu-2026-symptom-specific-links-between-depression-and-functional-impairment-in.md)
• Sexual dysfunction is infrequently recorded in psychiatric care, particularly among women; bupropion is preferentially prescribed for pre-existing anhedonia or sexual dysfunction. (source: isung-2026-patterns-and-treatment-of-sexual-dysfunction-in-major.md)
• In MDD, impaired low-frequency temporal prediction (below 1 Hz) is linked to psychomotor anhedonia and vegetative symptoms, suggesting dysfunction in motor-to-sensory predictive signaling rather than motor execution. (source: zhang-2026-impaired-low-frequency-temporal-prediction-links-to-psychomotor-dysfu.md)
• Anhedonia emerged as the most central symptom in bipolar depression, while persistent sadness was the most central in unipolar depression; global strength was higher in the BD network. (source: yoon-2026-how-do-network-structures-of-depressive-symptoms-differ.md)
• In a transdiagnostic network of affective and psychotic disorders, nodes from self- and observer-ratings formed strong bridges, especially concerning libido problems, lack of hobbies, social anhedonia, and loss of interest. (source: westhoff-2026-the-relationship-between-psychopathology-and-neurocognitive-functi.md)
• Remission of major depressive disorder was more likely among adults with better personality functioning and less trait detachment; trait detachment and impaired self functioning were the strongest predictors of non-remission. (source: vittengl-2026-prediction-of-remission-of-major-depressive-disorder-from.md)
• Perinatal alcohol exposure in mice induced sex-specific fear learning impairments and increased alcohol preference without inducing anhedonia in adolescence; in adulthood, males exhibited persistent increases in sucrose preference (suggesting reward sensitivity) and reduced anxiety-like behavior in females. (source: valverde-2026-perinatal-alcohol-exposure-disrupts-emotional-and-reward-processin.md)
• Clinically assessed anhedonia appears to be a state-dependent symptom that normalizes with remission of major depressive disorder. In contrast, reward-related learning, assessed via the Probabilistic Reward Task, was not significantly impaired in either current or remitted MDD, suggesting a dissociation between the experience of anhedonia and reward learning deficits. (source: g-rcan-2026-anhedonia-and-reward-learning-in-major-depression-state.md)
• In a network analysis of nursing students with recent suicidal ideation, anhedonia emerged as a critical bridge symptom linking anxiety, depression, and suicidal tendencies, alongside irritability and depressed mood. (source: nie-2026-network-analysis-of-anxiety-depressive-symptoms-and-suicidal.md)

Anhedonia in Menopause

• Research in menopause distinguishes that symptoms unique to anhedonia (as distinct from anxiety) are not related to vasomotor symptoms severity like hot flashes. Instead, anxious arousal is strongly linked to VMS. This challenges the depression narrative in menopause research. (source: behar-2026-rethinking-the-depression-narrative-in-menopause-research-delineating.md)

Stress and Anhedonia

• In a mouse model, unpredictable chronic mild stress (UCMS) impairs neuron-astroglial functional coupling in the prefrontal cortex, coinciding with the onset of anhedonia- and anxiety-like behavioral deficits. This positions impaired coupling as a potential substrate of stress-induced cortical dysfunction. (source: banasr-2026-in-vivo-cortical-neuron-astroglial-functional-coupling-strengthens-w.md)
• Chronic unpredictable stress (CUS) in rats increases anhedonia, alongside decreasing testosterone levels, FSH, and LH, and causing testicular dysfunction. (source: dubey-2026-chronic-stress-destabilizes-ectoplasmic-specialization-dynamics-in-th.md)
• Central hypocretin/orexin administration alleviates anhedonia and neuroinflammation in an animal model of seasonal affective disorder (SAD), suggesting the orexinergic system as a therapeutic target. (source: costello-2026-central-hypocretin-orexin-administration-alleviates-sleep-wake-dis.md)
• In male mice, estradiol via estrogen receptor β (ERβ) mediates stress susceptibility; absence of estradiol underlies susceptibility to stress-induced reward dysfunction, and activation of ERβ-projecting neurons from the basolateral amygdala to nucleus accumbens induces rewarding effects. (source: georgiou-2025-estradiol-via-estrogen-receptor-signaling-mediates-stress-suscepti.md)
• Subchronic PM2.5 exposure alone did not induce depression-like behaviors, but combined with chronic unpredictable mild stress (CUMS) it aggravated anhedonia, behavioral despair, and anxiety in mice, associated with hippocampal neuroinflammation, oxidative stress, and impaired synaptic plasticity. (source: lu-2026-subchronic-pm-lt-sub-gt-2-5-lt-sub-gt-exposure-exacerbates-chronic-stres.md)
• Three weeks of corticosterone in mice increased conflict levels without inducing anhedonia, and it abolished ketamine's anticonflict effect, indicating that chronic stress disrupts ketamine-responsive mechanisms. (source: hitora-imamura-2026-chronic-corticosterone-biases-conflict-related-behavior-and.md)
• Exposure to vegetated landscapes during recovery from chronic stress in mice improved anhedonia, anxiety-like behavior, and behavioral despair, with multistrata, color-rich landscapes producing the fastest recovery; these gains were accompanied by reduced IL-6 and IL-1β, normalized hippocampal Iba-1, preserved BDNF, and restored gut microbiome diversity linked to butyrate pathways. (source: zhang-2026-vegetation-structure-shapes-behavioral-neuroimmune-and-gut-microbial.md)

Neurobiology of Reward

• Blunted reward responsiveness during social feedback is associated with peer victimization and anhedonia in socially anxious adolescents. Socially anxious adolescents show suppressed ventral striatum (VS) activation during the potential for negative social feedback, which correlates with anhedonia. (source: carlton-2026-blunted-reward-responsiveness-during-social-feedback-associations-w.md)
• Sex differences in reward-related behavior appear early in adolescence, with boys showing higher reward motivation than girls. This is linked to pubertal stage and testosterone levels, though these associations change when controlling for age. (source: barendse-2024-sex-and-pubertal-variation-in-reward-related-behavior-and.md)
• Adolescent neural response to reward is related to participant sex and task motivation. Boys show heightened nucleus accumbens BOLD response during reward, but this sex difference is not mediated by sex hormones like testosterone or estradiol. (source: alarc-n-2016-adolescent-neural-response-to-reward-is-related-to.md)
• Reward sensitivity is more strongly associated with sensation seeking in males than females; reward sensitivity is unrelated to age but higher among those with more advanced pubertal development; there are positive associations with testosterone and negative associations with estradiol for sensation seeking. (source: harden-2017-developmental-differences-in-reward-sensitivity-and-sensation-seekin.md)
• In a physical effort task, females show more sustained effort, especially for small rewards, while males display opportunistic approaches seeking monetary rewards; motivation decreases during periovulatory and luteal phases, and high estradiol levels correlate with decreased motivation in both sexes. (source: grahlow-2026-motivation-and-reward-processing-across-sex-gender-and-the.md)
• Right ventral striatum activity moderates the association between lifetime trauma exposure and depression at 6 months in adolescents; greater trauma is associated with lower depression for those with higher right VS activity. (source: eckstrand-2026-adolescents-ventral-striatal-reward-neural-activity-moderates-the.md)
• In adolescent melancholic MDD, SPN (stimulus-preceding negativity) was positively correlated with anhedonia, while RewP (reward positivity) was negatively correlated with anhedonia; deep transcranial magnetic stimulation (dTMS) targeting the medial prefrontal cortex improved symptoms and these electrophysiological indices. (source: liu-2026-neuroelectrophysiological-clinical-exploration-of-reward-expectation-an.md)
• In adolescents with mood and anxiety symptoms, anhedonia severity correlated with default-mode network activation during uncertain outcome attainment; anxiety severity correlated with blunted striatal responses during uncertain vs. certain non-reward expectancy. (source: liu-2026-neural-response-to-reward-uncertainty-in-adolescents-with.md)
• The striatal brain regions (caudate-putamen, nucleus accumbens core and shell) mediate motivated behavior, reward, learning, and sensorimotor function, and these functions differ by sex or are sensitive to estradiol and testosterone; all three striatal regions express membrane-associated estrogen receptor. (source: meitzen-2018-sex-differences-and-the-effects-of-estradiol-on.md)
• The medial preoptic area (mPOA) sends sexually dimorphic projections to the ventral tegmental area (VTA): females have a greater percentage of efferents expressing ERα and males a greater percentage expressing androgen receptor. Most androgen receptor-expressing cells colocalize with GABAergic efferents to the VTA, but only a portion of ERα-expressing cells do. (source: martz-2023-sex-steroid-hormone-receptor-content-of-medial-preoptic.md)
• In MDD patients, blunted neural response to positive facial feedback (attenuated FRN) was associated with higher suicide risk; the high-suicide-risk group had the lowest FRN amplitudes, and FRN-gain correlated with consummatory anhedonia and suicide risk. (source: zhang-2026-blunted-neural-response-to-positive-facial-feedback-and.md)
• MDD is conceptualized as a pathological attractor emerging from hierarchical failure of top-down prefrontal cortex control, permitting pathological stabilization within subcortical hubs to drive anhedonia and motivational deficits; therapeutic intervention reshapes the functional landscape. (source: yuan-2026-a-circuit-based-framework-for-depression-reshaping-the-pathological.md)
• In melancholic depression, altered effective connectivity between reward network and triple network (default-mode network, executive control network, salience network) was observed, with increased excitatory connectivity from RN to ECN, and from ECN to DMN and SN; gene expression profiles implicated MAPK signaling pathways. (source: yan-2026-altered-effective-connectivity-among-reward-network-and-triple.md)

Treatments for Anhedonia

• In treatment-resistant depression (TRD), esketamine nasal spray, accelerated rTMS (arTMS), and adjunctive brexpiprazole all produce significant reductions in anhedonia. They show partially distinct symptom-domain profiles, with brexpiprazole improving pessimistic and ruminative symptoms, and esketamine enhancing affective responsiveness. (source: d-andrea-2026-dimensional-effect-profiles-in-treatment-resistant-depression-a-na.md)
• rTMS in TRD improves anhedonia and negative affect, and this is linked to three-component DMN-DAN network reorganization and coupled plasma miRNA changes. (source: bon-2026-three-component-dmn-dan-network-reorganization-and-coupled-plasma-mirna.md)
• The COMBAT-LLD study protocol aims to assess the effectiveness of combining rTMS with Behavioral Activation (BA) for late-life depression, with anhedonia and apathy as secondary outcomes. It hypothesizes that rTMS with BA leads to greater symptom reduction than rTMS alone. (source: de-2026-combining-behavioral-activation-and-repetitive-transcranial-magnetic-sti.md)
• Silexan (lavender oil preparation) was superior to placebo on 5 of 9 MADRS items (including lassitude and concentration difficulties) in mild-to-moderate MDD, with an overall antidepressant effect comparable to sertraline. (source: hans-j-rgen-2026-effects-of-lavender-oil-preparation-silexan-on-different.md)
• Escitalopram treatment in depression increases VTA activity during sustained effort expenditure, associated with improvement in clinician-rated depressive symptoms but not self-reported anhedonia. (source: hajri-2026-an-fmri-phenotype-of-reward-in-effort-expenditure.md)
• Positive affect (PA) increases (using an anhedonia measure), as well as increases in mindfulness, savoring, and gratitude, prospectively predicted lower depressive symptoms and suicide ideation in hospitalized adolescents. (source: macrynikola-2026-positive-affect-as-a-transdiagnostic-target-for-reducing.md)
• A combined SPS&S + CUMS paradigm in rats produced severe anhedonia and cognitive impairment, with region-specific alterations in AMPAR subunits and mTOR; paroxetine partially ameliorated both behavioral and molecular abnormalities. (source: jiang-2026-modelling-post-traumatic-stress-disorder-major-depressive-disorder-co.md)
• In CUMS mice, HF-rTMS ameliorated depressive-like behaviors and partially normalized sIPSC alterations in prefrontal cortex pyramidal neurons; these effects were attenuated by CB1R blockade (AM281). Glutamatergic CB1R signaling contributed to HF-rTMS modulation of presynaptic inhibitory function, while GABAergic CB1R ablation reduced stress vulnerability and shifted HF-rTMS actions toward postsynaptic modulation. (source: zhou-2026-cell-type-specific-cb1r-signaling-modulates-prefrontal-synaptic-respon.md)
• Ethyl acetate fraction of Chaidangbo prescription (EAFC) attenuated anhedonia and other depressive-like behaviors in CUMS mice, improved hippocampus synaptic structure and neurogenesis, and activated TrkB/PI3K/Akt signaling while increasing Akt-glucocorticoid receptor interaction to restrain GR nuclear translocation. (source: zeng-2026-ethyl-acetate-fraction-of-chaidangbo-prescription-eafc-improves.md)
• In treatment-resistant depression patients receiving short-term ketamine, anhedonia non-response was associated with fewer lifetime depressive episodes, lower rates of substance use disorder, and single marital status. (source: walaszek-2026-clinical-correlates-of-anhedonia-non-response-to-ketamine-in.md)
• A PEGylated nanographene oxide carrier for acteoside (PEG-nGO-ACT) improved brain delivery and showed stronger antidepressant responses in a mouse model, including reduction in anhedonia, by balancing GABA and glutamate levels. (source: huang-2026-a-functionalized-carbon-based-nano-delivery-system-for-braintargeted.md)
• The pan-salt-inducible kinase inhibitor YKL-06-061 exerts antidepressant-like effects via hippocampal CRTC1-CREB-BDNF pathway activation, reducing anhedonia in chronic social defeat stress and chronic unpredictable mild stress models in mice. (source: zhang-2026-the-pan-salt-inducible-kinase-inhibitor-ykl-06-061-exerts-antidepress.md)
• Cinnamic acid attenuated ciprofloxacin-induced depression-like behavior in mice, including anhedonia, through modulation of neuroinflammation, oxidative stress, and neurotransmitter homeostasis (serotonin, dopamine, GABA) in the hippocampus-prefrontal cortex axis. (source: alizade-2026-cinnamic-acid-attenuates-ciprofloxacin-induced-depression-like-beha.md)
• In a randomized controlled study of Behavioral Activation therapy for low mood, early reduction in aversive Pavlovian bias statistically mediated improvements in anhedonia, suggesting a specific cognitive mechanism through which BA exerts its therapeutic effects. (source: berndt-2026-early-reduction-in-aversive-pavlovian-bias-as-a.md)

Inflammation and Anhedonia

• The anti-inflammatory drug naproxen may reduce anhedonia in highly lonely individuals with concurrent elevated levels of perceived stress. In those with higher baseline stress, naproxen reduced anhedonia. (source: blandl-2026-breaking-the-cycle-of-loneliness-a-randomized-controlled.md)
• Tocilizumab (IL-6 receptor antagonist) in difficult-to-treat depression showed a pattern of improvement in somatic symptoms, depression severity, fatigue, anxiety, and quality of life; exploratory outcomes included anhedonia, and baseline hs-CRP tracked improvement. (source: foley-2026-interleukin-6-as-a-treatment-target-for-depression.md)
• Sedanolide (SD) alleviated LPS-induced depressive-like behaviors in mice, including anhedonia, by modulating the C3a/C3aR signaling axis and microglial glycolysis; pharmacological inhibition of C3aR abolished its effects. (source: lu-2026-sedanolide-alleviates-lps-induced-depressive-like-behaviors-by-modulatin.md)
• Fluoxetine combined with swimming exercise synergistically reduced LPS-induced anhedonia and behavioral despair in mice, normalizing the HPA axis (reducing corticosterone, increasing testosterone) and brain inflammation more effectively than either treatment alone. (source: mahdirejei-2023-fluoxetine-combined-with-swimming-exercise-synergistically-reduc.md)

Genetics and Anhedonia

• A global prospective harmonization framework for anhedonia, among other psychiatric phenotypes, is being developed within the NIMH Ancestral Population Network (APN) to enable genetic analysis across diverse ancestries. The Snaith-Hamilton Pleasure Scale will be used to assess anhedonia. (source: diaz-zuluaga-2026-a-global-prospective-harmonization-framework-for-suicidality-a.md)
• FGF13 was significantly reduced in serum of MDD patients; it regulates synaptic plasticity and neuronal apoptosis via the PI3K/AKT signaling pathway, and ROC analysis showed good diagnostic performance (AUC = 0.936). (source: hu-2026-fgf13-exerts-neuroprotective-effects-via-activation-of-the.md)

Anhedonia in Pregnancy and Postpartum

• Sadness and/or anhedonia for at least two consecutive weeks during pregnancy is a protective factor against non-use of antenatal mental health care among women in France. (source: doncarli-2026-non-use-of-antenatal-mental-health-care-among-women.md)
• Third-trimester plasma inflammatory markers (IL-1β, IL-6, IL-17A, CRP) are not significantly associated with postpartum anhedonia or other depressive symptoms in a large pregnancy cohort. (source: cohen-2026-examining-the-association-between-prenatal-inflammation-and-partpartum.md)
• Exposure to per- and polyfluoroalkyl substances (PFAS) showed inconsistent associations with postpartum psychological symptoms across two cohorts; the PFAS mixture at 1 month postpartum was associated with increased risk of anhedonia at 1 month in the PROGRESS cohort. (source: joseph-2026-association-between-per-and-polyfluoroalkyl-exposures-and-postpartum.md)

Psychosocial Factors and Anhedonia in Adolescence

• In adolescence, emotion regulation difficulties, perceived stress, and school environment are among the most central factors related to the presence of anhedonia as a core depressive symptom. (source: bu-inel-2026-a-network-analysis-of-psychosocial-risk-factors-and.md)
• In early adolescence, anhedonia predicted both overt and covert victimization; in middle adolescence, anhedonia predominantly predicted covert victimization, supporting the scar theory. (source: zhang-2026-developmental-changes-in-the-relationships-between-depressive-symptom.md)

Testosterone and Anhedonia

• In a large cohort of men, plasma androgens (including testosterone, DHT, and DHEAS) were not associated with current or onset of major depressive disorder or with anhedonia, except that free testosterone was inversely associated with interest in sex. This suggests circulating androgens from the testes have limited clinical relevance to MDD in men. (source: de-2021-plasma-androgens-and-the-presence-and-course-of.md)
• In aged Wistar rats, long-term hypogonadism and acute testosterone treatment had no effect on anhedonia or other depression-like behaviors. (source: borb-lyov-2016-no-effect-of-testosterone-on-behavior-in-aged.md)
• Chronic 17β-estradiol treatment in ovariectomized rats enhanced saccharin preference (an anhedonia measure) and novel object recognition, supporting an antidepressant-like action on anhedonia and memory. (source: gogos-2018-differential-effects-of-chronic-17-oestradiol-treatment-on-rat.md)
• Pituitary macroadenoma with panhypopituitarism can present with apathy and hypogonadism, masquerading as schizophrenia; conservative treatment with dopamine agonists and steroids improved psychiatric symptoms. (source: ghimire-2023-pituitary-macroadenoma-with-panhypopituitarism-masquerading-as-schi.md)
• Testosterone and cortisol interact in status competition: testosterone increases sensitivity to opponent status while decreasing sensitivity to gains and losses, and cortisol moderates these effects. (source: elahi-2026-separable-nonlinear-and-interactive-effects-of-testosterone-and.md)
• In adolescents, high testosterone with low cortisol is associated with greater conformity to high-prosocial peers, with neural activation in social cognition and reward regions (pSTS/TPJ, insula, OFC, caudate). (source: duell-2021-hormonal-and-neural-correlates-of-prosocial-conformity-in.md)
• Exogenous testosterone in healthy males eliminated strategic (feigned) prosocial behavior when being watched, by impacting choice consistency in a reinforcement learning task, without deteriorating learning per se. (source: kutlikova-2023-testosterone-eliminates-strategic-prosocial-behavior-through-impa.md; kutlikova-2022-testosterone-eliminates-strategic-prosocial-behavior-through-impa.md)
• Toludesvenlafaxine, a triple reuptake inhibitor (SERT, NET, DAT), demonstrated antidepressant-like effects in rat CUMS and olfactory bulbectomized models, significantly reduced serum corticosterone and increased testosterone levels, and improved anhedonia and sexual function. (source: zhu-2021-pharmacological-characterization-of-toludesvenlafaxine-as-a-triple-reup.md)
• In mice, testosterone-dependent lower excitability of ventral hippocampus (vHPC) to nucleus accumbens (NAc) neurons underlies male resilience to stress-induced anhedonia; DREADD stimulation of vHPC-NAc caused decreased sucrose preference in males, while inhibition prevented it in females. (source: williams-2019-androgen-dependent-excitability-of-mouse-ventral-hippocampal-affer.md)
• Tadalafil prevented CUMS-induced anhedonia and sexual dysfunction in male rats, without affecting serum testosterone, dopamine, or 5-HT levels. (source: wang-2023-effects-of-tadalafil-on-sexual-behavior-of-male.md)
• Exogenous testosterone administration in healthy males increased prosocial learning rates and reward sensitivity across self, other, and computer conditions, supporting the social status hypothesis. (source: wang-2023-can-testosterone-modulate-prosocial-learning-in-healthy-males.md)
• Exogenous testosterone administration in the context of energy deficit did not impact risky choice but increased sensitivity to negative feedback following risky choices; brain activation in the thalamus covaried with individual differences in the reflection effect. (source: vartanian-2022-effect-of-exogenous-testosterone-in-the-context-of.md)
• Exogenous testosterone administration disrupted resting-state connectivity within fronto-subcortical and fronto-parietal circuits, decreasing connectivity between right DLPFC and right amygdala, and between VMPFC and left IPL. (source: votinov-2020-effects-of-exogenous-testosterone-application-on-network-connectivi.md)
• Testosterone plays a pivotal role in maintaining balance within the multi-dimensional psychological network of mood, behaviour, self-perception and perceived quality of life in men of any age. Low testosterone concentrations, seen in age- and comorbidity-driven functional hypogonadism, might relate to depressive symptoms ranging from dysthymia and fatigue to hopelessness and suicidal thoughts. Testosterone modulates stress resilience, threat vigilance, and reward processing, and influences pro-active and re-active aggression within the context of gaining or maintaining status. The genetic setting of the androgen receptor modulates testosterone's role in mood and personality. Testosterone substitution can positively influence quality of life in older hypogonadal men. (source: zitzmann-2020-testosterone-mood-behaviour-and-quality-of-life.md)

Cortical Function and Anhedonia

• In depression, brain imaging shows that while medicated patients have stabilized limbic responses to positive social situations, the superior frontal gyrus (SFG) and posterior right ventrolateral PFC are hypoactive, and dorsolateral PFC and anterior right vlPFC are hyperactive, revealing impaired cognitive control pathways for positive emotion regulation. (source: bezmaternykh-2026-persistent-anhedonic-dysregulation-of-positive-social-emotion.md)

Anhedonia and Obesity

• A systematic review finds that elevated anhedonia is associated with higher BMI, emotional eating, reduced motivation, and poorer adherence to lifestyle interventions; genetic evidence supports shared pathways, including FTO polymorphisms and Mendelian randomization suggesting a directional effect of BMI on anhedonia. (source: hajje-2026-the-association-between-anhedonia-and-obesity-a-systematic.md)

Anhedonia in Substance Use Disorders

• In cocaine use disorder, higher anhedonia is associated with reduced differentiation in valence ratings of emotional images (emotional flattening), but this is not mirrored in physiological measures like heart rate or corrugator EMG. (source: gurrieri-2026-cocaine-use-disorder-anhedonia-and-emotional-flattening-in.md)
• Spontaneous withdrawal from oxycodone in mice decreased marble burying (suggesting anhedonia) and altered oligodendrocyte-related gene expression (downregulation of Tcf7l2 and Klk6) in the medial prefrontal cortex. (source: law-2026-spontaneous-oxycodone-withdrawal-alters-behavior-and-oligodendrocyte-re.md)

Glymphatic System and Anhedonia

• Patients with major depressive disorder (MDD) and bipolar disorder (BD) show reduced DTI-ALPS indices and gBOLD-CSF coupling compared to healthy controls, indicating glymphatic system impairment; this impairment is associated with increased anhedonia in MDD and poorer sleep in BD, and mediation analysis suggests gBOLD-CSF coupling mediates the association between disease status and affective symptoms. (source: fu-2026-structural-and-functional-glymphatic-abnormalities-in-major-depressive.md)
• In treatment-resistant depression patients, elevated left-side and mean DTI-ALPS indices were observed, with reduced left Dyyproj values; higher DTI-ALPS index was associated with more severe sleep disturbance, while lower Dyyproj values correlated with lower anxiety and cognitive impairment; in nTRD, lower DTI-ALPS index was associated with more childhood trauma and milder anhedonia. (source: zhang-2026-assessment-of-glymphatic-function-in-treatment-resistant-depression-u.md)

Environmental Enrichment Loss and Anhedonia

• In the enrichment-loss rodent model, flexible-coping male rats in continuous enriched environments consumed more food rewards than other groups; enrichment-loss animals exhibited a blunted corticosterone response, and enriched flexible copers had faster CORT recovery rates. (source: kent-2022-the-emotional-impact-of-disrupted-environmental-contexts-enrichment.md)

PTSD and Anhedonia

• A modified single prolonged stress (mSPS) paradigm in mice, combined with single housing, induced a PTSD-like phenotype with anhedonia; 29.76% of mSPS mice were classified as susceptible, similar to human trauma incidence. (source: holman-2026-development-of-a-novel-analysis-method-for-evaluating.md)
• In adolescents after a natural disaster, arousal symptoms (sleep disturbance, startle, concentration problems) were stable bridge symptoms between PTSD and depression across two years; anhedonia became a prominent bridge symptom in the later stage (15-27 months). (source: yang-2026-the-role-of-arousal-symptoms-in-ptsd-and.md)

Biomarkers and Therapeutic Targets

• Ethanolamine may be a potential biomarker and therapeutic target for depressive disorder. (source: ogawa-2026-ethanolamine-as-a-potential-biomarker-and-therapeutic-target.md)
• Tirzepatide may reduce anhedonia-like symptoms in patients with obesity. (source: nadolsky-2026-resolution-of-anhedonia-like-symptoms-in-patients-treated-for.md)

Anhedonia in Medical Conditions

• A case report describes a woman in her early sixties with hypothyroidism and glaucoma presenting with low mood, anhedonia, somnolence, anxiety, and other symptoms, who was diagnosed with celiac disease after serology and biopsy. Symptoms improved substantially with gluten-free diet and other interventions. (source: karczewski-2026-histologically-confirmed-celiac-disease-in-a-multifactorial-prim.md)
• In movement disorder patients (Parkinson's disease and essential tremor) with depression, corticostriatal alpha-beta power (8-30 Hz) increased during reward feedback, but this increase was attenuated in depressed subjects in both caudate and dorsolateral prefrontal cortex; BDI-II score negatively predicted reward- and loss-related power, and in Parkinson's disease specifically, depressed patients had greater decreases in DLPFC alpha-beta power following loss feedback. (source: qian-2026-movement-disorder-patients-with-depression-have-altered-corticostriata.md)

Anhedonia and Physical Health

• An exploratory review found that anhedonia is significantly associated with all-cause mortality, risk of major adverse cardiovascular events, and worse physical health-related quality of life; high positive affect was correlated with lower risk of functional decline, reduced inflammatory biomarkers, and protective effects against diabetes and hypertension. (source: demyttenaere-2026-the-impact-of-anhedonia-on-physical-health-and.md)

Ideas

• The relationship between anhedonia and reward processing is complex and multifaceted, and further research is needed to fully understand the underlying mechanisms. (idea)
• The development of effective treatments for anhedonia is crucial, and may involve targeting the glymphatic system or using ethanolamine as a therapeutic agent. (idea)
• The state-dependent nature of anhedonia in MDD suggests that treatments targeting reward learning may not be effective for current anhedonia. (connection)
• The case of celiac disease presenting with anhedonia highlights the need to screen for medical conditions in patients with anhedonia. (gap)
• Altered corticostriatal alpha-beta power during reward and loss in movement disorder patients with depression suggests a shared neural mechanism for anhedonia across neurological and psychiatric conditions. (connection)
• Vegetation structure as a tunable environmental intervention for stress recovery highlights the potential of nature-based therapies for anhedonia. (idea)
• Early reduction in aversive Pavlovian bias mediates anhedonia improvement during Behavioral Activation, providing a mechanistic biomarker for treatment response. (connection)
• Anhedonia is associated with worse physical health outcomes including cardiovascular events and mortality, suggesting that treating anhedonia may have broad health benefits. (gap)
• Anhedonia as a bridge symptom between anxiety, depression, and suicidal tendencies in nursing students highlights the need for targeted interventions in high-risk groups. (gap)