Anhedonia in Depressive Disorder: A Narrative Review

Effect of venlafaxine on anhedonia and amotivation in patients with major depressive disorder

OBJECTIVE

Serotonin norepinephrine reuptake inhibitors (SNRIs) have been postulated to afford benefits in alleviating anhedonia and amotivation. This post hoc pooled analysis evaluated the effect of venlafaxine XR, an SNRI, on these symptoms in patients with major depressive disorder (MDD).

METHODS

Data was pooled from five short-term randomized, placebo-controlled studies of venlafaxine XR for the treatment of MDD, comprising 1087 (venlafaxine XR, n = 585; placebo, n = 502) adult subjects. The change from baseline score in the MADRS anhedonia factor (based on items 1 [apparent sadness], 2 [reported sadness], 6 [concentration difficulties], 7 [lassitude], and 8 [inability to feel]) for anhedonia, and in motivational deficits (based on 3 items of HAM-D17: involvement in work and activities, psychomotor retardation, and energy level [ie, general somatic symptoms]) for amotivation, were measured through 8 weeks. Mixed model repeated measures (MMRMs) were used to analyze changes over time and ANCOVA to analyze the change from baseline at week 8 with LOCF employed to handle missing data.

RESULTS

At the end of 8 weeks, the change from baseline was significantly greater in patients on venlafaxine XR in both anhedonia (mean, 95% CI: -2.73 [-3.63, -1.82], p < 0.0001) and amotivation scores (mean, 95% CI: -0.78 [-1.04, -0.52], p < 0.0001) than those on placebo. For both measures, the between-group separation from baseline was statistically significant starting from week 2 onwards, and it increased over time.

CONCLUSION

This analysis demonstrates that venlafaxine XR is effective in improving symptoms of anhedonia and motivational deficits in patients with MDD.

Perspectives on the impact of vortioxetine on the treatment armamentarium of major depressive disorder

INTRODUCTION

Major Depressive Disorder (MDD) is a mental health issue that significantly affects patients' quality of life and functioning. Despite available treatments, many patients continue to suffer due to incomplete symptom resolution and side effects.

AREAS COVERED

This manuscript examines Vortioxetine's role in Major Depressive Disorder (MDD) treatment, highlighting its potential to reshape therapeutic strategies due to its unique Multimodal action and proven broad-spectrum efficacy in multiple depressive domains. A detailed examination of Vortioxetine's pharmacological aspects, including indications, dosage, pharmacodynamics, and pharmacokinetics, is provided, emphasizing its safety and effectiveness. The discussion extends to Vortioxetine's role in acute-phase treatment and maintenance of MDD and its profound impact on specialized depression domains.

EXPERT OPINION

Vortioxetine is distinguished for its novel multimodal serotonin modulation mechanism, showcasing significant promise as an innovative treatment for MDD. Its efficacy, which is dose-dependent, along with a commendable tolerability profile, positions it as a potential leading option for initial treatment strategies. The discourse on dosage titration, particularly the strategy of initiating treatment at lower doses followed by gradual escalation, underscores the approach toward minimizing initial adverse effects while optimizing therapeutic outcomes, aligning with the principles of personalized medicine in psychiatric care.

Infant hedonic/anhedonic processing index (HAPI-Infant): Assessing infant anhedonia and its prospective association with adolescent depressive symptoms

BACKGROUND

Anhedonia, an impairment in the motivation for or experience of pleasure, is a well-established transdiagnostic harbinger and core symptom of mental illness. Given increasing recognition of early life origins of mental illness, we posit that anhedonia should, and could, be recognized earlier if appropriate tools were available. However, reliable diagnostic instruments prior to childhood do not currently exist.

METHODS

We developed an assessment instrument for anhedonia/reward processing in infancy, the Infant Hedonic/Anhedonic Processing Index (HAPI-Infant). Exploratory factor and psychometric analyses were conducted using data from 6- and 12-month-old infants from two cohorts (N = 188, N = 212). Then, associations were assessed between infant anhedonia and adolescent self-report of depressive symptoms.

RESULTS

The HAPI-Infant (47-items), exhibited excellent psychometric properties. Higher anhedonia scores at 6 (r = 0.23, p < .01) and 12 months (r = 0.19, p < .05) predicted elevated adolescent depressive symptoms, and these associations were stronger than for established infant risk indicators such as negative affectivity. Subsequent analyses supported the validity of short (27-item) and very short (12-item) versions of this measure.

LIMITATIONS

The primary limitations of this study are that the HAPI-Infant awaits additional tests of generalizability and of its ability to predict clinical diagnosis of depression.

CONCLUSIONS

The HAPI-Infant is a novel, psychometrically strong diagnostic tool suitable for recognizing anhedonia during the first year of life with strong predictive value for later depressive symptoms. In view of the emerging recognition of increasing prevalence of affective disorders in children and adolescents, the importance of the HAPI-Infant in diagnosing anhedonia is encouraging. Early recognition of anhedonia could target high-risk individuals for intervention and perhaps prevention of mental health disorders.

Evolution of anhedonia in adolescent depression: An interpretative phenomenological analysis study

INTRODUCTION

Anhedonia is a symptom complex currently linked to dysfunctional reward processing. Phenomenological studies capture anhedonia as a loss of hedonic and eudemonic pleasure. However, there is a lack of integration between neurobiological understanding and clinical phenomenology. This study used a qualitative method to explore the interplay of sociocultural contexts and individual factors associated with the evolution of dysfunctional reward processing in adolescents with depression and anhedonia.

METHODS

Ten female adolescents with a current or prior diagnosis of major depressive disorder were recruited from a public tertiary care child and adolescent psychiatry service. In-depth interviews were conducted, voice recorded, and transcribed verbatim. The transcripts were analyzed using Interpretative Phenomenological Analysis (IPA).

FINDINGS

The adolescents hailed from urban families. Educational stress and relational difficulties figured prominently. Amotivation was the most important subdomain of anhedonia affected. An integrated framework for understanding the evolution of anhedonia is presented. Five main patterns of dysfunctional reward processing emerged in our study: an overworked system, erroneous reward valuation, reward-effort imbalance, and diversion of the reward processing system for self-preservation.

CONCLUSION

There is a necessity to build robust theoretical models of the evolution of anhedonia, hence finding homogenous sub-groups, paving the way for person-centric interventions for anhedonia.

Anhedonia in Acne Vulgaris: A Cross-Sectional Study of 104 Consecutive Acne Patients

Background

Anhedonia is defined as a reduced ability to experience or even a total loss of pleasure.

Purpose

This study was undertaken to evaluate anhedonia in 104 consecutive acne patients.

Material and Methods

Acne severity was assessed with Investigator Global Assessment (IGA), anhedonia was studied with the Snaith-Hamilton Pleasure Scale (SHAPS), Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS) and Temporal Experience of Pleasure Scale (TEPS). Moreover, the quality of life (QoL) and stigmatization, as well as depression and anxiety (Hospital Anxiety and Depression Scale - HADS), were additionally evaluated.

Results

Anhedonia was found in 20.19% of acne patients and was more common (p=0.007) in males (34.29%) than in females (13.04%). Based on SHAPS, males with acne showed significantly (p=0.049) higher levels of anhedonia (2.39 ± 3.18 points) than acne females (1.26 ± 2.36 points). Anhedonia significantly correlated with the clinical acne severity (SHAPS: r=0.205, p=0.038 and ACIPS: r=-0.222, p=0.026). Although the intensity of anhedonia did not show any relationship with QoL and stigmatization assessments, there was a significant correlation between anhedonia and depressive symptoms (SHAPS: r=0.310, p<0.001; ACIPS: r=-0.364, p<0.001). Such dependency was not documented for anxiety.

Conclusion

Anhedonia seems to be a common phenomenon in acne and should be considered in the holistic approach to acne patients.

Validation of the maximal cardiopulmonary exercise test in adolescents with major depressive disorder and comparison of cardiorespiratory fitness with sex- and age-related control values

Endurance training has been shown to be effective in treating adolescents with major depressive disorder (MDD). To integrate endurance training into the therapeutic setting and the adolescents' daily lives, the current performance status of the adolescents should be accurately assessed. This study aims to examine adolescents with MDD concerning exhaustion criteria during a cardiopulmonary exercise test (CPET), as well as to compare the values obtained thereon with sex- and age-related control values. The study included a retrospective examination of exhaustion criteria ((i) oxygen consumption (V̇O2) plateau, (ii) peak respiratory exchange ratio (RERpeak) > 1.0, (iii) peak heart rate (HRpeak) ≥ 95% of the age-predicted maximal HR, and (iv) peak blood lactate concentration (BLCpeak) > 8.0 mmol⋅L-1) during a graded CPET on a cycle ergometer in adolescents with MDD (n = 57). Subsequently, maximal V̇O2, peak minute ventilation, V̇O2 at the first ventilatory threshold, and peak work rate of participants who met at least two of four criteria were compared with published control values using an independent-sample t-test. Thirty-three percent of the total population achieved a V̇O2 plateau and 75% a RERpeak > 1.0. The HR and BLC criteria were met by 19% and 22%, respectively. T-test results revealed significant differences between adolescents with MDD and control values for all outcomes. Adolescents with MDD achieved between 56% and 83% of control values.   Conclusions: The study shows that compared with control values, fewer adolescents with MDD achieve the exhaustion criteria on a CPET and adolescents with MDD have significantly lower cardiorespiratory fitness.   Clinical trial registration: No. U1111-1145-1854. What is Known: • It is already known that endurance training has a positive effect on depressive symptoms. What is New: • A relevant proportion of adolescents with major depressive disorder do not achieve their V̇O2max during a graded cardiopulmonary exercise test. • Adolescents with major depressive disorder have significantly lower cardiorespiratory fitness compared to sex- and age-related control values.

The longitudinal relationship between bullying victimization and depressive symptoms for middle school students: A cross-lagged panel network analysis

BACKGROUND

Previous research about the relationship between bullying victimization and adolescent depressive symptoms was mostly based on latent variable modeling. This study, instead, applied item-level analysis to explore the cross-sectional relationship and longitudinal development between bullying victimization and adolescent depressive symptoms with network models.

METHODS

This study used Olweus Bully/Victim Questionnaire and Children's Depression Inventory to collect data. A total of 1911 middle school students (55.2 % female; Mage = 12.98 ± 0.60 at T1) completed measures on four occasions at 6-month intervals. Nine network analysis models were employed to better understand the relationship between variables.

RESULTS

(1) "Being threatened or intimidated" was the most influential bullying behavior within bullying victimization items; (2) "being excluded", "being spoken ill of" and "negative mood" were the bridge items between bullying victimization and adolescent depressive symptoms; (3) the most influential bullying victimization item on adolescent depressive symptoms was "being robbed or blackmailed" for short-term development and "being excluded" for long-term development. While the most affected depressive symptom by bullying victimization was "anhedonia" for short-term development and "negative mood" for long-term development.

LIMITATIONS

Self-report measure is adopted for all variables in the study, and there may be some deviation. Due to the questionnaires, the items of bullying behaviors and depressive symptoms included in the network analysis are limited.

CONCLUSIONS

From the item level, this study found more specific relationships between bullying victimization and adolescent depressive symptoms. These findings highlight depressed mood and anhedonia are depressive symptoms that should be more paid attention to in clinical intervention for bullying victims.

Effectiveness of online cognitive behavioural therapy on quality of life in adults with depression: A systematic review

WHAT IS KNOWN ON THE SUBJECT

Depression is a leading cause of disability worldwide that negatively impacts quality of life. Talk therapy such as cognitive behavioural therapy is an effective treatment for depression. The Internet is an important tool for mental healthcare delivery. Internet-delivered or online talk therapy interventions are associated with lower costs and improved accessibility. Current reviews do not address the effectiveness of Internet-delivered cognitive behavioural therapy (iCBT) on quality of life (QoL).

WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE

Interventions for iCBT have better QoL improvements for individuals with greater depressive symptom severity, females, young adults and individuals with complex comorbid disorders. Support from a healthcare provider for iCBT interventions have better outcomes than self-guided therapy interventions. Tailoring the iCBT intervention to the specialized needs of the population is beneficial.

WHAT ARE THE IMPLICATIONS FOR PRACTICE

There is potential to address treatment gaps for managing the care of individuals with depression. Utilizing iCBT promotes the integration of accessible mental healthcare in clinical settings. Healthcare providers can have a more comprehensive approach to delivering iCBT by considering adaptations relevant to the clinical population being treated.

ABSTRACT

INTRODUCTION: Major depressive disorder (MDD) is a leading cause of disability resulting from social, psychological and biological factors affecting quality of life (QoL). Cognitive behavioural therapy (CBT) is an effective psychotherapy for MDD. Internet-delivered CBT (iCBT) is associated with lower costs and improved accessibility.

AIM

We aimed to examine the effectiveness of iCBT on QoL in adults with depression.

METHOD

PubMed, Embase and PsycINFO were searched between 2010 and 2022. Inclusion criteria were experimental designs, adults ≥18 years old, depression diagnosis or valid self-report measure, iCBT intervention; and QoL outcome. Exclusion criteria were studies without depression analysis and intellectual disabilities or psychosis.

RESULTS

Seventeen articles were included, with a negative correlation between depression severity and QoL. Sex, age and physical comorbidity positively influenced effectiveness. Depressive severity, dysfunctional attitude and negative thinking were predictors and moderators of QoL. Clinician support can impact social interactions and sense of belonging.

DISCUSSION

Internet-delivered cognitive behavioural therapy is effective for improving QoL in adults with MDD. Severe depression, females, younger age and comorbid disorders were associated with greater QoL improvements.

IMPLICATIONS FOR PRACTICE

The findings suggest iCBT could address depression treatment gaps related to improving QoL. Utilizing iCBT potentially improves the care continuum for individuals with complex disorders.

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.

Emotional behaviors as well as the hippocampal reelin expression in C57BL/6N male mice chronically treated with corticosterone

Depression is a common psychiatric disorder affecting around 300 million people worldwide. Serum cortisol and glucocorticoid levels in humans are reportedly higher in patients with depression compared to controls. Furthermore, rodents repeatedly treated with exogenous corticosterone (CORT), a glucocorticoid in rodents, exhibit deficits in emotional behaviors. To confirm the availability of mice with chronic CORT treatment as an animal model of depression, we investigated the effect of chronic CORT treatment on depression-like behavioral and neuropathological phenotypes in C57BL/6N male mice. Behavioral studies showed depression- and anxiety-like behaviors in mice treated with CORT compared with control mice in the forced-swim and elevated-plus maze tests. Additionally, treated mice represented anhedonia and social behavior impairments in the sucrose preference and social interaction tests, respectively. Brains of depression patients have altered expression of reelin, an extracellular matrix protein involved in neuronal development and function. Likewise, in the present study, mice with chronic CORT treatment also exhibited reelin downregulation in cells of the hippocampus. Hence, we investigated therapeutic effects of reelin supplementation on CORT-induced behavioral abnormalities in mice. Microinjections of recombinant reelin protein into the hippocampus did not rescue behavioral deficits in mice with chronic CORT treatment. These results suggest that C57BL/6N male mice chronically treated with CORT are a suitable animal depression model, in which depressive behaviors may occur independently of the alternation of hippocampal Reelin expression.

Depression severity is associated with reduced pleasantness of observed social touch and fewer current intimate touch experiences

Depression is associated with loss of pleasure in previously enjoyed activities and withdrawal from social interactions. Depression alters the perception of social cues, but it is currently unclear whether this extends to social touch. In the current cross-sectional study, we explored the association between depression severity, perceived pleasantness of observed social touch, and general longing for touch. For observed touch, we contrasted videos of slow touch (1-10cm/s), which optimally activates C tactile afferent nerve fibres and generally feels pleasant, with 'non-CT-optimal' touch (i.e., outside the 1-10cm/s range, commonly rated more neutral). We predicted that greater depression severity would be related to lower pleasantness ratings specifically for CT-optimal touch, and less longing for touch. N = 226 adults completed self-report measures of depression severity and longing for touch, and rated touch pleasantness for six videos depicting social touch at three velocities (3cm/s in the CT-optimal range, 0.5 and 30cm/s outside this range) and at two locations varying in CT innervation (palm vs. arm). We controlled for general anhedonia and individual differences in touch experiences and attitudes. Across touch locations, greater depression severity was associated with lower perceived pleasantness of touch, especially for the fastest non-CT-optimal (rather than the CT-optimal) velocity, contrary to our prediction. However, when grouping participants into probable vs. no/minimal depression, the probable depression group rated both the fastest non-CT-optimal and the CT-optimal velocity as less pleasant than did the no/minimal depression group. Overall, while depression was associated with perceived pleasantness of observed touch, this was not specific to CT-optimal touch. Furthermore, touch longing was not associated with depression severity. Instead, variance in depression symptoms was better explained by reduced levels of current intimate touch. Though the direction of causality is unclear, greater depression severity is related to lower pleasantness of observed social touch, and lower levels of current intimate touch.

Heat-Killed L. helveticus Enhances Positive Mood States: A Randomized, Double-Blind, Placebo-Controlled Study

When mood states are impaired, daily life is severely disrupted. To maintain a specific mood state, both positive and negative moods must be controlled; however, methods to maintain a positive mood have not been fully established. Previous studies have suggested that heat-killed L. helveticus MCC1848 has the potential to improve positive moods. This study aimed to test the efficacy of heat-killed L. helveticus MCC1848 in maintaining and improving a positive mood with PANAS, a questionnaire specifically designed to assess positive and negative mood, as the primary endpoint. Healthy Japanese nursing students (n = 46) were randomized to receive heat-killed L. helveticus MCC1848 (5 billion/day) or placebo powder for four weeks. Mood state was assessed before and two and four weeks after the intervention began; ingestion of heat-killed L. helveticus MCC1848 significantly improved PANAS 'Positive Affect' compared to the placebo. These results indicate that heat-killed L. helveticus MCC1848 is effective in enhancing positive mood.

Electroacupuncture prevents astrocyte atrophy to alleviate depression

Astrocyte atrophy is the main histopathological hallmark of major depressive disorder (MDD) in humans and in animal models of depression. Here we show that electroacupuncture prevents astrocyte atrophy in the prefrontal cortex and alleviates depressive-like behaviour in mice subjected to chronic unpredictable mild stress (CUMS). Treatment of mice with CUMS induced depressive-like phenotypes as confirmed by sucrose preference test, tail suspension test, and forced swimming test. These behavioural changes were paralleled with morphological atrophy of astrocytes in the prefrontal cortex, revealed by analysis of 3D reconstructions of confocal Z-stack images of mCherry expressing astrocytes. This morphological atrophy was accompanied by a decrease in the expression of cytoskeletal linker Ezrin, associated with formation of astrocytic leaflets, which form astroglial synaptic cradle. Electroacupuncture at the acupoint ST36, as well as treatment with anti-depressant fluoxetine, prevented depressive-like behaviours, astrocytic atrophy, and down-regulation of astrocytic ezrin. In conclusion, our data further strengthen the notion of a primary role of astrocytic atrophy in depression and reveal astrocytes as cellular target for electroacupuncture in treatment of depressive disorders.

Associations between resting state functional brain connectivity and childhood anhedonia: A reproduction and replication study

BACKGROUND

Previously, a study using a sample of the Adolescent Brain Cognitive Development (ABCD)® study from the earlier 1.0 release found differences in several resting state functional MRI (rsfMRI) brain connectivity measures associated with children reporting anhedonia. Here, we aim to reproduce, replicate, and extend the previous findings using data from the later ABCD study 4.0 release, which includes a significantly larger sample.

METHODS

To reproduce and replicate the previous authors' findings, we analyzed data from the ABCD 1.0 release (n = 2437), from an independent subsample from the newer ABCD 4.0 release (excluding individuals from the 1.0 release) (n = 6456), and from the full ABCD 4.0 release sample (n = 8866). Additionally, we assessed whether using a multiple linear regression approach could improve replicability by controlling for the effects of comorbid psychiatric conditions and sociodemographic covariates.

RESULTS

While the previously reported associations were reproducible, effect sizes for most rsfMRI measures were drastically reduced in replication analyses (including for both t-tests and multiple linear regressions) using the ABCD 4.0 (excluding 1.0) sample. However, 2 new rsfMRI measures (the Auditory vs. Right Putamen and the Retrosplenial-Temporal vs. Right-Thalamus-Proper measures) exhibited replicable associations with anhedonia and stable, albeit small, effect sizes across the ABCD samples, even after accounting for sociodemographic covariates and comorbid psychiatric conditions using a multiple linear regression approach.

CONCLUSION

The most statistically significant associations between anhedonia and rsfMRI connectivity measures found in the ABCD 1.0 sample tended to be non-replicable and inflated. Contrastingly, replicable associations exhibited smaller effects with less statistical significance in the ABCD 1.0 sample. Multiple linear regressions helped assess the specificity of these findings and control the effects of confounding covariates.

Heat-killed Lactobacillus helveticus improves mood states: a randomised, double-blind, placebo-controlled study

We investigated the effects of heat-killed Lactobacillus helveticus MCC1848 on daily mood states in healthy young adults. Participants (n=58) were randomised to receive heat-killed L. helveticus MCC1848 powder or placebo powder for 4 weeks. During the study period, adverse events were recorded in the participant diary. Mood states were assessed before and 2 and 4 weeks after initiation of the intervention. The primary outcomes were the shortened version of the Profile of Mood States 2 (POMS 2) scores. Secondary outcomes included other mood state (State-Trait Anxiety Inventory (STAI); visual analogue scale (VAS)), quality of life (acute form of the SF-36v2), sleep (Athens Insomnia Scale (AIS)) and fatigue (Chalder Fatigue Scale (CFS)) scores. Four weeks of heat-killed L. helveticus MCC1848 intake, compared to placebo, significantly improved the shortened version of the POMS 2 'friendliness' and the VAS 'relaxed' scores, which are two indicators of positive mood states. On the other hand, heat-killed L. helveticus MCC1848 intake had no significant effects on negative mood state items (e.g. anger, nervousness, confusion) assessed by the shortened version of the POMS 2, STAI and VAS. AIS and CFS scores also showed no significant differences. No adverse effects were observed with 4 weeks of heat-killed L. helveticus MCC1848 intake. These results suggest that daily consumption of heat-killed L. helveticus MCC1848 is safe and has the potential to improve positive mood states. UMIN Clinical Trial Registry: UMIN000043697.

Changes in white matter microstructure following serial ketamine infusions in treatment resistant depression

Ketamine produces fast-acting antidepressant effects in treatment resistant depression (TRD). Though prior studies report ketamine-related changes in brain activity in TRD, understanding of ketamine's effect on white matter (WM) microstructure remains limited. We thus sought to examine WM neuroplasticity and associated clinical improvements following serial ketamine infusion (SKI) in TRD. TRD patients (N = 57, 49.12% female, mean age: 39.9) received four intravenous ketamine infusions (0.5 mg/kg) 2-3 days apart. Diffusion-weighted scans and clinical assessments (Hamilton Depression Rating Scale [HDRS-17]; Snaith Hamilton Pleasure Scale [SHAPS]) were collected at baseline and 24-h after SKI. WM measures including the neurite density index (NDI) and orientation dispersion index (ODI) from the neurite orientation dispersion and density imaging (NODDI) model, and fractional anisotropy (FA) from the diffusion tensor model were compared voxelwise pre- to post-SKI after using Tract-Based Spatial Statistics workflows to align WM tracts across subjects/time. Correlations between change in WM metrics and clinical measures were subsequently assessed. Following SKI, patients showed significant improvements in HDRS-17 (p-value = 1.8 E-17) and SHAPS (p-value = 1.97 E-10). NDI significantly decreased in occipitotemporal WM pathways (p < .05, FWER/TFCE corrected). ΔSHAPS significantly correlated with ΔNDI in the left internal capsule and left superior longitudinal fasciculus (r = -0.614, p-value = 6.24E-09). No significant changes in ODI or FA were observed. SKI leads to significant changes in the microstructural features of neurites within occipitotemporal tracts, and changes in neurite density within tracts connecting the basal ganglia, thalamus, and cortex relate to improvements in anhedonia. NODDI may be more sensitive for detecting ketamine-induced WM changes than DTI.

Anhedonia and sensitivity to punishment in schizophrenia, depression and opiate use disorder

BACKGROUND

From a behavioural perspective anhedonia is defined as diminished interest in the engagement of pleasurable activities. Despite its presence across a range of psychiatric disorders, the cognitive processes that give rise to anhedonia remain unclear.

METHODS

Here we examine whether anhedonia is associated with learning from positive and negative outcomes in patients diagnosed with major depression, schizophrenia and opiate use disorder alongside a healthy control group. Responses in the Wisconsin Card Sorting Test - a task associated with healthy prefrontal cortex function - were fitted to the Attentional Learning Model (ALM) which separates learning from positive and negative feedback.

RESULTS

Learning from punishment, but not from reward, was negatively associated with anhedonia beyond other socio-demographic, cognitive and clinical variables. This impairment in punishment sensitivity was also associated with faster responses following negative feedback, independently of the degree of surprise.

LIMITATIONS

Future studies should test the longitudinal association between punishment sensitivity and anhedonia also in other clinical populations controlling for the effect of specific medications.

CONCLUSIONS

Together the results reveal that anhedonic subjects, because of their negative expectations, are less sensitive to negative feedbacks; this might lead them to persist in actions leading to negative outcomes.

The Motivation and Energy Inventory (MEI): Analysis of the clinically relevant response threshold in patients with major depressive disorder and emotional blunting using data from the COMPLETE study

BACKGROUND

The Motivation and Energy Inventory (MEI) is a patient-reported scale for assessment of the impact of mental/cognitive energy, social motivation, and physical energy on daily functioning in patients with major depressive disorder (MDD). This analysis was undertaken to establish the clinically relevant response threshold for the MEI in patients with MDD receiving antidepressant treatment.

METHODS

Patients with MDD experiencing inadequate response and emotional blunting on selective serotonin reuptake inhibitor or serotonin-noradrenaline reuptake inhibitor monotherapy (adequate dose for ≥6 weeks) were switched to vortioxetine 10-20 mg/day for 8 weeks. Anchor- and distribution-based methods were used to determine the minimal clinically important difference (MCID) in MEI total score.

RESULTS

After 8 weeks of vortioxetine treatment, mean (standard deviation) change in MEI total score from baseline was 33.0 (27.3) points. At week 8, mean change in MEI total score from baseline was 37.5 (27.8) points in patients no longer reporting emotional blunting and 28.3 (26.2) points in those still experiencing emotional blunting. In patients considered minimally improved (i.e. Clinical Global Impression-Improvement [CGI-I] score of 3 after 8 weeks of vortioxetine), mean change in MEI total score from baseline was 14.7 (19.1) points. In patients defined as responders (CGI-I score of 2 at 8 weeks), mean change in MEI total score was 33.0 (24.7) points.

LIMITATIONS

Short study duration.

CONCLUSIONS

These results provide further validation of the clinical utility of the MEI for assessing treatment response in patients with MDD. The suggested MCID for MEI total score is 15 points.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03835715.

Escaping negative moods and concentration problems play bridge roles in the symptom network of problematic smartphone use and depression

Background

Problematic smartphone use (PSU) has become an issue of great concern in the age of smartphones. PSU is associated with emotional problems, one of which is depression, as shown by empirical studies. However, previous studies have been limited in that they have focused solely on the total score for symptoms of PSU and depression while ignoring the symptomatic heterogeneity of these two concepts.

Method

This study filled this gap by exploring links between symptoms of PSU and depression among 1,849 university students (59.17% female participants, 17-23 years old). Network analysis was utilized to reveal symptom connections, central symptoms, and bridge symptoms between PSU and depression.

Results

(1) A total of 17 of 81 symptom connections (about 21%) between PSU and depression existed in the symptom network. For example, "self-control failure" for PSU was positively correlated with "concentration problems" for depression; (2) "recklessly continuing" for PSU and "fatigue" for depression were central symptoms within the PSU symptom network and depression symptom network, respectively; (3) "escaping negative moods" for PSU and "concentration problems" for depression were bridge symptoms. The former was maximumly connected with the depression symptoms and the latter was maximumly connected with the PSU symptoms; and (4) gender had very minimal influence on the network characteristics.

Conclusion

The results are in keeping with the central idea of the compensatory internet use theory that excessive smartphone use may be a coping strategy for depressed emotions derived from escaping motivation. Moreover, concentration problems may be a mediator explaining how negative emotions (e.g., depression) cause PSU, which is undefined in current internet use theories. Finally, symptom connections, central symptoms, and bridge symptoms could be potential targets for the prevention and intervention of PSU and depression in young adults.

The Relationship between Social Anhedonia and Perceived Pleasure from Food-An Exploratory Investigation on a Consumer Segment with Depression and Anxiety

Anhedonia, the diminished ability to experience pleasure, is a key symptom of a range of mental and neurobiological disorders and is associated with altered eating behavior. This research study investigated the concept of anhedonia in relation to mental disorders and the perception of pleasure from food to better understand the link between anhedonia and eating behavior. A consumer survey (n = 1051), including the Food Pleasure Scale, the Chapman Revised Social Anhedonia Scale, the Patient Health Questionnaire, and the Generalized Anxiety Disorder scale, was conducted to explore the perception of pleasure from food among people with anhedonic traits. Comparative analyses were performed between people with symptoms of depression and/or anxiety and people with no symptoms of these conditions. A segmentation analysis was furthermore performed based on three levels of anhedonia: Low, Intermediate and High anhedonia. Thus, insights into how food choice and eating habits may be affected by different levels of anhedonia are provided for the first time. Our findings showed that the 'Low anhedonia' segment found pleasure in all aspects of food pleasure, except for the aspect 'eating alone'. 'Eating alone' was, however, appreciated by the 'Intermediate anhedonia' and 'High anhedonia' segments. Both the 'Intermediate anhedonia' and 'High anhedonia' segments proved that their perceptions of food pleasure in general were affected by anhedonia, wherein the more complex aspects in particular, such as 'product information' and 'physical sensation', proved to be unrelated to food pleasure. For the 'High anhedonia' segment, the sensory modalities of food were also negatively associated with food pleasure, indicating that at this level of anhedonia the food itself is causing aversive sensations and expectations. Thus, valuable insights into the food pleasure profiles of people with different levels of anhedonia have been found for future research in the fields of mental illness, (food) anhedonia, and consumer behaviors.

The anti-anxiety/depression effect of a combined complex of casein hydrolysate and γ-aminobutyric acid on C57BL/6 mice

In view of a series of adverse side effects of drugs for anxiety/depression on the market at present, it is imminent to extract and develop novel anti-anxiety and depression drugs from plants and proteins (like casein hydrolysate) as adjuncts or substitutes for existing anti-anxiety and depression drugs. Consequently, this study investigated the improvement of the anxiety/depression function by the compound of casein hydrolysate and γ-aminobutyric acid (GABA) (casein hydrolysate: GABA = 4:1; CCHAA) on mice induced by chronic restraint stress-corticosterone injection. Animal experiments revealed that oral gavage administration of CCHAA significantly reversed the anxiety/depression-like behaviors. Compared to the model control group, body weights were increased after treatment with CCHAA groups [1.5, 0.75 mg/(g⋅d)]. As a diagnostic index of anxiety and depression, we assessed GABA and 5-HT levels in response to CCHAA ingestion. The GABA and 5-HT levels were increasingly enhanced by the CCHAA diet. In addition, histopathological changes in the hippocampus CA3 region of the anxious/depressed mice were also alleviated after the treatment with the CCHAA. Thus, the casein hydrolysate and GABA formula diets may induce beneficial effects on the mice with anxiety/depression.

The diagnostic and predictive potential of personality traits and coping styles in major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a global public health concern that is notably underdiagnosed and undertreated due to its complexity and subjective diagnostic methods. A holistic diagnostic procedure, which sufficiently considers all possible contributors to MDD symptoms, would improve MDD diagnosis and treatment. This study aims to explore whether personality and coping styles can predict MDD status and differentiate between depressed patients and healthy individuals.

METHODS

Seventy healthy controls (N = 54 females) were matched to 70 MDD patients for age, sex, ethnicity, and years of education. MDD severity was measured using the Hamilton Depression Rating Scale, while personality traits and coping styles were measured by the Ten-Item Personality (TIPI) and Brief COPE questionnaires, respectively. Logistic regression analyses were conducted to investigate the diagnostic and predictive potential of personality and coping styles. Receiver operating characteristic (ROC) analyses were also conducted to examine their discriminative ability to distinguish between depressed and healthy individuals.

RESULTS

Introversion, lack of organisation skills, and neuroticism were statistically significant in predicting MDD status. Dysfunctional coping strategies, such as denial and self-blame, were also shown to significantly predict MDD status. ROC analyses found both the TIPI questionnaire (AUC = 0.90), and dysfunctional coping (as measured by Brief COPE) (AUC = 0.90) to be excellent predictors of MDD.

CONCLUSIONS

Our findings demonstrate the diagnostic and predictive potential of personality and coping styles for MDD in the clinical setting. They also demonstrate the remarkable ability of personality and coping styles to differentiate between depressed patients and healthy controls.

Mood Disturbances Across the Continuum of Care Based on Self-Report and Clinician Rated Measures in the interRAI Suite of Assessment Instruments

BACKGROUND

Mood disturbance is a pervasive problem affecting persons of all ages in the general population and the subset of those receiving services from different health care providers. interRAI assessment instruments comprise an integrated health information system providing a common approach to comprehensive assessment of the strengths, preferences and needs of persons with complex needs across the continuum of care.

OBJECTIVE

Our objective was to create new mood scales for use with the full suite of interRAI assessments including a composite version with both clinician-rated and self-reported items as well as a self-report only version.

METHODS

We completed a cross-sectional analysis of 511,641 interRAI assessments of Canadian adults aged 18+ in community mental health, home care, community support services, nursing homes, palliative care, acute hospital, and general population surveys to develop, test, and refine new measures of mood disturbance that combined clinician and self-rated items. We examined validity and internal consistency across diverse care settings and populations.

RESULTS

The composite scale combining both clinician and self-report ratings and the self-report only variant showed different distributions across populations and settings with most severe signs of disturbed mood in community mental health settings and lowest severity in the general population prior to the COVID-19 pandemic. The self-report and composite measures were strongly correlated with each other but differed most in populations with high rates of missing values for self-report due to cognitive impairment (e.g., nursing homes). Evidence of reliability was strong across care settings, as was convergent validity with respect to depression/mood disorder diagnoses, sleep disturbance, and self-harm indicators. In a general population survey, the correlation of the self-reported mood scale with Kessler-10 was 0.73.

CONCLUSIONS

The new interRAI mood scales provide reliable and valid mental health measures that can be applied across diverse populations and care settings. Incorporating a person-centered approach to assessment, the composite scale considers the person's perspective and clinician views to provide a sensitive and robust measure that considers mood disturbances related to dysphoria, anxiety, and anhedonia.

Anhedonia in Eating Disorders

Anhedonia is frequently observed among individuals with eating disorders (ED), though its relevance to ED pathology and clinical outcomes remain poorly understood. This chapter will present the latest findings regarding anhedonia in ED, with the majority of data available for anorexia nervosa (AN) and bulimia nervosa (BN). We consider anhedonia from the mechanistic lens of altered reward processing, with attention given to subjective experience, neurotransmitter function, neural correlates, and cognitive performance corresponding to distinct components of reward (i.e., liking, wanting, and learning). Findings from animal models are also highlighted. The chapter concludes with a discussion of implications for treatment and future directions aimed at better understanding anhedonia in ED.

Towards Modeling Anhedonia and Its Treatment in Zebrafish

Mood disorders, especially depression, are a major cause of human disability. The loss of pleasure (anhedonia) is a common, severely debilitating symptom of clinical depression. Experimental animal models are widely used to better understand depression pathogenesis and to develop novel antidepressant therapies. In rodents, various experimental models of anhedonia have already been developed and extensively validated. Complementing rodent studies, the zebrafish (Danio rerio) is emerging as a powerful model organism to assess pathobiological mechanisms of affective disorders, including depression. Here, we critically discuss the potential of zebrafish for modeling anhedonia and studying its molecular mechanisms and translational implications.

The Relationship Between State Loneliness and Depression Among Youths During COVID-19 Lockdown: Coping Style as Mediator

The coronavirus disease (COVID-19) pandemic has had a great impact on public mental health. However, loneliness during the lockdown related to depression and whether the relationship would be mediated by coping style or whether sex moderates loneliness and coping style are not clear. The study aimed to examine the mediating role of coping style in the relationship between state loneliness and depression as well as the moderating role of sex in the relationship between state loneliness and coping styles during the COVID-19 lockdown. Participants were 337 college students in China during the COVID-19 pandemic (January–February 2020). States of depression and anxiety, state loneliness, and coping styles with COVID-19 were measured. The results show that loneliness was an effective predictor of depression during self-quarantine. Moreover, coping style mediated the relationship between state loneliness and depression although sex did not moderate the relationship between state loneliness and coping style. Youths were inclined to use more positive coping strategies than negative coping strategies. Our results indicate less loneliness is an effective way to relieve depression, and coping strategies, especially the positive ones, are important for youths to prevent depression and loneliness during the lockdown of the COVID-19 pandemic.

Molecular and functional properties of cortical astrocytes during peripherally induced neuroinflammation

Astrocytic contributions to neuroinflammation are widely implicated in disease, but they remain incompletely explored. We assess medial prefrontal cortex (PFC) and visual cortex (VCX) astrocyte and whole-tissue gene expression changes in mice following peripherally induced neuroinflammation triggered by a systemic bacterial endotoxin, lipopolysaccharide, which produces sickness-related behaviors, including anhedonia. Neuroinflammation-mediated behavioral changes and astrocyte-specific gene expression alterations peak when anhedonia is greatest and then reverse to normal. Notably, region-specific molecular identities of PFC and VCX astrocytes are largely maintained during reactivity changes. Gene pathway analyses reveal alterations of diverse cell signaling pathways, including changes in cell-cell interactions of multiple cell types that may underlie the central effects of neuroinflammation. Certain astrocyte molecular signatures accompanying neuroinflammation are shared with changes reported in Alzheimer's disease and mouse models. However, we find no evidence of altered neuronal survival or function in the PFC even when neuroinflammation-induced astrocyte reactivity and behavioral changes are significant.

The Effects of Anhedonia in Social Context

Purpose of Review

Anhedonia is a transdiagnostic symptom comprising reduced subjective reward or pleasure. Anhedonia influences subjective anticipation and in-the-moment experiences. This review draws together affective learning and engagement evidence for anhedonia affecting subjective experiences of social environments.

Recent Findings

While social engagement is diminished consistently, subjective appraisals of social contexts vary across different mental health disorders. Low positive affect during social experiences or stimuli is reported in PTSD, mood, schizophrenia, and anxiety disorders. Diminished neural reward networks underpin the anticipation of social experiences in ADHD, schizophrenia spectrum, and autistic spectrum disorders. Multiple theories exist to explain how anhedonia might interfere with social environments.

Summary

Anhedonia is a barrier to engagement, motivation, and enjoyment of social contexts. While many studies characterize experiences during social contexts, learning theories provide the most promise for developing targeted interventions.

Exploring anhedonia in adolescents with Chronic Fatigue Syndrome (CFS): A mixed-methods study

BACKGROUND

Chronic Fatigue Syndrome (CFS/ME) may get in the way of enjoying activities. A substantial minority of adolescents with CFS/ME are depressed. Anhedonia is a core symptom of depression. Anhedonia in adolescents with CFS/ME has not been previously investigated.

METHOD

One hundred and sixty-four adolescents, age 12 to 18, with CFS/ME completed a diagnostic interview (K-SADS) and questionnaires (HADS, RCADS). We used a mixed-methods approach to explore the experience of anhedonia and examine how common it is, comparing those with clinically significant anhedonia to those without.

RESULTS

Forty-two percent of adolescents with CFS/ME reported subclinical or clinical levels of anhedonia. Fifteen percent had clinically significant anhedonia. Thematic analysis generated two themes: (1) stopping activities that they previously enjoyed and (2) CFS/ME obstructs enjoyment. Most (72%) of those who reported clinically significant anhedonia met the depression diagnostic criteria. Those who were depressed used more negative language to describe their experience of activities than in those who were not depressed, although the themes were broadly similar.

CONCLUSIONS

Experiencing pleasure from activities may be affected in CFS/ME, particularly in those who are depressed. Anhedonia may get in the way of behavioural strategies used within CFS/ME treatments.

Efficacy of Vortioxetine on Anhedonia: Results from a Pooled Analysis of Short-Term Studies in Patients with Major Depressive Disorder

PURPOSE

Anhedonia is a core symptom of major depressive disorder (MDD), which has important functional consequences for the patient. This post hoc analysis investigated the relationship between anhedonia and functioning in patients with MDD treated with vortioxetine.

PATIENTS AND METHODS

We conducted a pooled analysis of all 11 short-term, double-blind, randomized, placebo-controlled studies of vortioxetine (fixed dose, 5-20 mg/day) in patients with MDD which included Montgomery-Åsberg Depression Rating Scale (MADRS) and Sheehan Disability Scale (SDS) assessments. A short-term, randomized, active-controlled trial of flexible-dose treatment with vortioxetine (10-20 mg/day) versus agomelatine (25-50 mg/day) was also analyzed. Mean changes from baseline to study endpoint in MADRS total, MADRS anhedonia subscale, SDS total, and SDS social-functioning scores were analyzed by a mixed model for repeated measures. The relationship between treatment effects on anhedonia and functioning was investigated using path analysis.

RESULTS

A total of 4988 patients with MDD were included in the placebo-controlled studies and 495 in the active-comparator study. Significant dose-dependent improvements in overall depressive symptoms, anhedonia, and measures of functioning were seen in vortioxetine-treated patients compared with those who received placebo or agomelatine. Results of the path analysis for the placebo-controlled studies suggested that the effect on functioning was mostly driven by the effect of treatment on MADRS anhedonia factors.

CONCLUSION

Vortioxetine showed significant short-term efficacy against anhedonia in this large population of patients with MDD. In the placebo-controlled studies, improvements in functioning associated with vortioxetine appeared to be mostly driven by the effect of treatment on MADRS anhedonia factors.