Anhedonia: a concept analysis

Childhood unpredictability is associated with increased risk for long- and short-term depression and anhedonia symptoms following combat deployment

High unpredictability has emerged as a dimension of early-life adversity that may contribute to a host of deleterious consequences later in life. Early-life unpredictability affects development of limbic and reward circuits in both rodents and humans, with a potential to increase sensitivity to stressors and mood symptoms later in life. Here, we examined the extent to which unpredictability during childhood was associated with changes in mood symptoms (anhedonia and general depression) after two adult life stressors, combat deployment and civilian reintegration, which were assessed ten years apart. We also examined how perceived stress and social support mediated and /or moderated links between childhood unpredictability and mood symptoms. To test these hypotheses, we leveraged the Marine Resiliency Study, a prospective longitudinal study of the effects of combat deployment on mental health in Active-Duty Marines and Navy Corpsman. Participants (N = 273) were assessed for depression and anhedonia before (pre-deployment) and 3-6 months after (acute post-deployment) a combat deployment. Additional assessment of depression and childhood unpredictability were collected 10 years post-deployment (chronic post-deployment). Higher childhood unpredictability was associated with higher anhedonia and general depression at both acute and chronic post-deployment timepoints (βs ≥ 0.16, ps ≤.007). The relationship between childhood unpredictability and subsequent depression at acute post-deployment was partially mediated by lower social support (b = 0.07, 95% CI [0.03, 0.15]) while depression at chronic post-deployment was fully mediated by a combination of lower social support (b = 0.14, 95% CI [0.07, 0.23]) and higher perceived stress (b = 0.09, 95% CI [0.05, 0.15]). These findings implicate childhood unpredictability as a potential risk factor for depression in adulthood and suggest that increasing the structure and predictability of childhood routines and developing social support interventions after life stressors could be helpful for preventing adult depression.

Determining cut-off values and predictors for the Snaith-Hamilton Pleasure Scale: comparison between clinical and school settings

BACKGROUND

Few previous studies have established Snaith-Hamilton Pleasure Scale (SHAPS) cut-off values using receiver operating characteristic curve analysis and applied these values to compare predictors of anhedonia between clinical and nonclinical groups.

AIMS

To determine the optimal cut-off values for the SHAPS and use them to identify predictors of anhedonia in clinical and nonclinical groups in Taiwan.

METHOD

This cross-sectional and correlational study used convenience sampling to recruit 160 patients from three hospitals and 412 students from two universities in northern Taiwan. Data analysis included receiver operating characteristic curve, univariate and multivariate analyses.

RESULTS

The optimal SHAPS cut-off values were 29.5 and 23.5 for the clinical and nonclinical groups, respectively. Moreover, two-stage analysis revealed that participants in the clinical group who perceived themselves as nondepressed, and participants in the nonclinical group who did not skip classes and whose fathers exhibited higher levels of care and protection were less likely to attain the cut-off values. Conversely, participants in the nonclinical group who reported lower academic satisfaction and were unwilling to seek help from family or friends were more likely to attain the cut-off values.

CONCLUSIONS

Our findings highlight the importance of optimal cut-off values in screening for depression risk within clinical and nonclinical groups. Accordingly, the development of comprehensive, individualised programmes to monitor variation trends in SHAPS scores and relevant predictors of anhedonia across different target populations is crucial.

Assessing the Link Between General Causality Orientations and Problem Gambling, and the Mediational Role of Nonattachment, Greed, and Anhedonia

Gambling is common in the US, yet nearly one in three players experience gambling-related problems. Using Self-Determination Theory, this study explores how three causality orientations-autonomous, controlled, and impersonal-affect the severity of problem gambling. The study further investigates the mediating roles of nonattachment, dispositional greed, and anhedonia to illuminate how these orientations relate to problem gambling. The data from 675 participants (59% male; Mean age = 40.4 years, SD = 12.9) via Amazon's Mechanical Turk were collected following a screening procedure to identify at-risk players. Findings showed that dispositional greed mediated the impact of a controlled orientation on problem gambling severity, while anhedonia mediated the effect of impersonal orientation. Unexpectedly, nonattachment did not explain the effect of autonomous orientation on problem gambling, though a negative association was still observed. This research enhances understanding of how individual differences and causality orientations contribute to problem gambling behavior. The implications are discussed.

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

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

Anhedonia and Depressive Disorders

Anhedonia is a core symptom of depression and of several psychiatric disorders. Anhedonia has however expanded from its original definition to encompass a spectrum of reward processing deficits that received much interest in the last decades. It is a relevant risk factor for possible suicidal behaviors, and that it may operate as an independent risk factor for suicidality apart from the episode severity. Anhedonia has also been linked to inflammation with a possible reciprocal deleterious effect on depression. Its neurophysiological bases mainly include alterations in striatal and prefrontal areas, with dopamine being the most involved neurotransmitter. Anhedonia is thought to have a significant genetic component and polygenic risk scores are a possible tool for predicting an individual's risk for developing anhedonia. Traditional antidepressants, such as selective serotonin reuptake inhibitors, showed a limited benefit on anhedonia, also considering their potential pro-anhedonic effect in some subjects. Other treatments may be more effective in treating anhedonia, such as agomelatine, vortioxetine, ketamine and transcranial magnetic stimulation. Psychotherapy is also widely supported, with cognitive-behavioral therapy and behavioral activation both showing benefit. In conclusion, a large body of evidence suggests that anhedonia is, at least partially, independent from depression, therefore it needs careful assessment and targeted treatment.

Factorial and network structure of the Reynolds Adolescent Depression Scale (RADS-2) in Peruvian adolescents

Depression in young people is considered a public health problem, given that it affects their personal, social, and academic lives; therefore, early detection of depressive symptoms is of importance for a favorable prognosis. This study aimed to estimate the psychometric properties of the second edition of the Reynolds Adolescent Depression Scale (RADS-2) in Peruvian adolescents. The sample was composed of 917 Peruvian adolescents, aged 13 to 18 years (M = 15,241, SD = 1,020), who were selected from two public educational institutions in Metropolitan Lima. Confirmatory factor analysis supported the 25-item model with the four-dimensional structure and its overall and interdimensional reliability. This structure was found to be gender invariant. Finally, network analysis was performed to assess the relationships and centralities of the depressive symptoms of the validated version of the RADS-2. The results show that the RADS-2 measure is a consistent and reliable test that yields valid results in the Peruvian adolescent context.

Subjective Impact of Age-Related Hearing Loss Is Worse for Those Who Routinely Experience Boredom and Failures of Attention

OBJECTIVES

Despite extensive evidence supporting the benefits of hearing treatments for individuals affected by hearing loss, many leave their hearing issues unaddressed. This underscores the need to better understand the individual factors influencing decision-making regarding hearing loss treatments. One consideration regarding the low uptake of treatment is the finding that the subjective impact of hearing loss is greater for some individuals than for others, yielding a significant discrepancy between subjective measures of hearing loss (e.g., self-report hearing-handicap scales) and objective audiometric assessments (e.g., audiograms). The current study seeks to elucidate some of the cognitive-affective factors that give rise to these individual differences in the subjective impact of hearing loss. Specifically, we hypothesized that a stronger trait tendency to experience boredom would be correlated with more intensely negative experiences of hearing-related issues, and that this relationship would be mediated by underlying attentional difficulties.

METHODS

Through a partnership with hearing care clinics (Connect Hearing Canada), we recruited a large sample of older adults (n = 1840) through their network of hearing-care clinics. Audiometric thresholds provided an objective measure of hearing ability for each participant, while self-report questionnaires assessed individual differences in the subjective impact of hearing-related issues (hearing handicap), subjective strain experienced when listening (listening effort), tendency to experience boredom, tendency to experience difficulty maintaining task-focused attention (mind-wandering), and self-perceived level of cognitive functioning.

RESULTS

The subjective impact of hearing loss-both in terms of hearing handicap and strain when listening-was found to be more intensely negative for those who are characteristically more susceptible to experiencing boredom, and this relationship was shown to be mediated by self-reported differences in the ability to maintain task-focused attention. This relationship between trait boredom proneness and the subjective impact of hearing-related issues was evident across all levels of objective hearing abilities. Moreover, there was no evidence that the subjective impact of hearing loss is worse for those who routinely experience boredom because of objectively-poorer hearing abilities in those individuals.

CONCLUSIONS

A greater trait susceptibility to experiencing boredom was associated with a more aversive subjective experience of hearing loss, and this relationship is mediated by attentional difficulties. This is a novel discovery regarding the cognitive-affective factors that are linked to individual differences in the effect that hearing loss has on individuals' daily functioning. These results may be helpful for better understanding the determinants of hearing-rehabilitation decisions and how to improve the uptake of treatments for hearing loss. The observational nature of the current study restricts us from drawing any definitive conclusions about the casual directions among the factors being investigated. Further research is therefore needed to establish how individual differences in the characteristic tendency to experience boredom are related to attentional-control difficulties and the experience of hearing-related issues. More research is also required to determine how all of these factors may influence decisions regarding hearing-loss treatments.

Orgasm and Related Disorders Depend on Neural Inhibition Combined With Neural Excitation

INTRODUCTION

Prevalent models of sexual desire, arousal and orgasm postulate that they result from an excitatory process, whereas disorders of sexual desire, arousal and orgasm result from an inhibitory process based on psychosocial, pharmacological, medical, and other factors. But neuronal excitation and active neuronal inhibition normally interact at variable intensities, concurrently and continuously. We propose herein that in conjunction with neuronal excitation, neuronal inhibition enables the generation of the intense, non-aversive pleasure of orgasm. When this interaction breaks down, pathology can result, as in disorders of sexual desire, arousal, and orgasm, and in anhedonia and pain. For perspective, we review some fundamental behavioral and (neuro-) physiological functions of neuronal excitation and inhibition in normal and pathological processes.

OBJECTIVES

To review evidence that the variable balance between neuronal excitation and active neuronal inhibition at different intensities can account for orgasm and its disorders.

METHODS

We selected studies from searches on PubMed, Google Scholar, Dialnet, and SciELO for terms including orgasm, neuronal development, Wallerian degeneration, prenatal stress, parental behavior, sensorimotor, neuronal excitation, neuronal inhibition, sensory deprivation, anhedonia, orgasmic disorder, hypoactive sexual desire disorder, persistent genital arousal disorder, sexual pain.

RESULTS

We provide evidence that the intensity of neuronal inhibition dynamically covaries concurrently with the intensity of neuronal excitation. Differences in these relative intensities can facilitate the understanding of orgasm and disorders of orgasm.

CONCLUSION

Neuronal excitation and neuronal inhibition are normal, continuously active processes of the nervous system that are necessary for survival of neurons and the organism. The ability of genital sensory stimulation to induce concurrent neuronal inhibition enables the stimulation to attain the pleasurable, non-aversive, high intensity of excitation characteristic of orgasm. Excessive or deficient levels of neuronal inhibition relative to neuronal excitation may account for disorders of sexual desire, arousal and orgasm.

An evolutionary investigation of depressed mood: The relationship between daily stressors and patterns of depressive symptoms

BACKGROUND AND OBJECTIVES

The situation-symptom congruence hypothesis (SSCH; (Keller & Nesse, 2006), grounded in evolutionary theory, argues that different types of adversity should lead to distinct patterns of depressive symptoms that help individuals deal with adaptive challenges. Situation-symptom congruence hypotheses were tested in this study using experience sampling methodology.

METHODS

Two hundred and sixty-five individuals, including 54% who scored at least 16 on the Center for Epidemiologic Studies Revised Depression Scale, responded to text prompts daily for up to 9 days, reporting depressive symptoms as well as the most stressful event or issue they had experienced or focused on within the past 24 h.

RESULTS

Multilevel modeling analyses indicated that the relationships between stressors and depressive symptom patterns were largely consistent with SSCH predictions. All stressors were significantly associated with symptoms hypothesized to be adaptive in response to those stressors. Moreover, in separate analyses, nine of the ten symptoms examined were either predicted by the stressors hypothesized to lead to that symptom or negatively related to stressors hypothesized to not elicit those symptoms.

LIMITATIONS

It is unclear whether the results generalize to those diagnosed with a major depressive disorder; the study did not assess actual life events.

CONCLUSIONS

Findings suggest that depressive symptoms may, in part, be adaptations that have evolved through natural selection to help individuals cope with adverse situations.

The effect of ketamine on anhedonia: improvements in dimensions of anticipatory, consummatory, and motivation-related reward deficits

Anhedonia is a common, persistent, and disabling condition. However, available therapeutics primarily focus on the reduction of depressive and negative symptoms rather than amelioration of deficits in positive affect. As such, extant drug treatments remain largely ineffective in treating symptoms of anhedonia. Ketamine is a rapid-acting and novel therapeutic treatment for treatment-resistant depression, which has also been demonstrated to attenuate symptoms of anhedonia. However, the literature on the anti-anhedonic effects of ketamine is limited-especially within independent dimensions of this symptom domain. Herein, this review examined the impact of ketamine treatment on anhedonia and its dimensions on anticipatory, consummatory, and motivation-related reward deficits. Overall, the findings have shown a trend towards symptom reduction and/or improvements in anhedonia and their respective subdomains, in both human and preclinical studies, as well as its potential to provide additional benefit in reducing suicidality and improving quality-of-life. Although further research is required in understanding the long-term efficacy and mechanism, ketamine may provide an effective and rapid-acting therapeutic in an otherwise unmet domain.

The Transdiagnostic Nature of Social Anhedonia: Historical and Current Perspectives

In this chapter, we trace the historical roots of the social anhedonia (SoA) construct to current conceptualizations. We first describe the aspects of SoA that distinguish it from anhedonia in general. We summarize evidence that SoA is a transdiagnostic symptom and risk factor. Although several forms of psychopathology are associated with elevated rates of self-reported SoA, one unresolved issue is whether the processes and mechanisms underlying SoA in one disorder are the same as the processes and mechanisms underlying SoA seen in another disorder. We assert that there may be different causal factors underlying SoA across disorders. Considering both the principles of equifinality and multifinality, we offer an integrative model for social reward processing. This conceptualization considers roles for the following: attention; social cognition, including, but not limited to, social skills; reward learning and valuation; working memory; anticipation, prediction, and remembering; and motivation and effort. We conclude that SoA may be caused by multiple underlying impairments, all of which may serve as targets for intervention. This conceptualization is provided as an impetus for further research in the area.

Psychometric properties of the Dimensional Anhedonia Rating Scale in Chinese typical, subthreshold, and clinically depressed adolescents

The Dimensional Anhedonia Rating Scale measures state anhedonia in multiple domains, such as hobbies, food and drink, social activities, and sensory experience, and it has good reliability and validity in adult samples. However, no study has examined the psychometrical properties of this scale in adolescents. The present study examined its reliability and validity in adolescents with and without depression. In Study 1, 988 high-school students completed the Dimensional Anhedonia Rating Scale; 915 completed the second-round survey 3 months later. Confirmatory factor analysis was used to determine the factor structure. Additionally, internal consistency and test-retest reliability, and concurrent, convergent, and divergent validity were assessed in typical adolescents. In Study 2, the Dimensional Anhedonia Rating Scale was administrated to 108 patients with major depressive disorder, 108 adolescents with subthreshold depression, and 108 healthy controls. Factor structure and convergent validity were assessed in the clinical and subclinical groups. Finally, a one-way analysis of variance (ANOVA) was applied to examine the effect of depression severity on the scale scores. The results of Study 1 indicated that a four-factor model (i.e., hobbies, food and drink, social activities, and sensory experience) best fit the data. Meanwhile, the scale also yielded good concurrent, convergent, and divergent validity, as well as high internal consistency and test-retest reliability, in typical adolescents. In Study 2, goodness-of-fit statistics also suggested a good fit for the four-factor model in the two depressed groups. The one-way ANOVA revealed significant group differences in the total and factor scores, whereby the major depressive disorder group had lower scores than the subthreshold depression group, whose scores were lower than the healthy controls, indicating excellent eligibility of the scale in depressed adolescents. The Chinese version of the Dimensional Anhedonia Rating Scale is a reliable and valid instrument to comprehensively measure state anhedonia in Chinese typical and depressed adolescents.

Validation of the Oxford Depression Questionnaire: Sensitivity to change, minimal clinically important difference, and response threshold for the assessment of emotional blunting

BACKGROUND

The Oxford Depression Questionnaire (ODQ) is a patient-reported scale for assessing emotional blunting in patients with major depressive disorder (MDD). This analysis was undertaken to further validate the scale in patients experiencing emotional blunting while receiving antidepressant treatment.

METHODS

Patients with MDD who experienced inadequate depressive-symptom resolution 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. ODQ total scores were assessed excluding and including the "antidepressant-as-cause" domain (ODQ-20 and ODQ-26, respectively). Anchor- and distribution-based methods were used to determine the minimal clinically important difference in ODQ scores in terms of change from baseline to week 8 of antidepressant treatment.

RESULTS

After 8 weeks of vortioxetine treatment, the mean change in ODQ-20 and ODQ-26 scores from baseline was -24.8 and -30.1 points, respectively. Greater mean changes from baseline in ODQ-20 and ODQ-26 scores were seen in patients reporting no emotional blunting vs those still experiencing emotional blunting after 8 weeks of vortioxetine treatment (ODQ-20: -27.0 vs -22.6 points; ODQ-26: -32.8 vs -27.5 points, respectively). In patients considered clinically minimally improved (Clinical Global Impression-Improvement score, 3) after 8 weeks of vortioxetine treatment, respective mean (standard deviation) change in ODQ-20 and ODQ-26 score from baseline was -15.5 (18.1) and -20.0 (20.5) points.

LIMITATIONS

Short study duration.

CONCLUSIONS

These results provide further validation of the clinical utility of the ODQ for assessing emotional blunting in patients with MDD. The suggested minimal clinically important difference for change in ODQ-20 and ODQ-26 scores is 16 and 20 points, respectively, after 8 weeks of antidepressant treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03835715.

Anhedonia in tobacco withdrawal among African-American smokers

Anhedonia-diminished interest and pleasure in response to rewards-may be a symptom of tobacco withdrawal that is understudied in priority populations. This experiment investigated the magnitude and correlates of various dimensions of anhedonia during tobacco withdrawal among African-American (AA) smokers-a population subject to health disparities. AA smokers (N = 607; ≥ 10 cigarettes/day, 37.8% female, M[SD] age = 50.0[10.6] years) completed self-report measures assessing expected pleasure from (i.e., consummatory anhedonia) and desire to engage in (i.e., anticipatory anhedonia) various types of hypothetically experienced rewards at counterbalanced 16-hr tobacco deprived and nondeprived lab visits. Other tobacco withdrawal symptom measures (e.g., craving, negative affect, hunger) were also assessed. Tobacco deprivation most robustly increased scores on a composite measure of consummatory anhedonia directed toward various reward domains (i.e., hobbies, sensory experiences, social activities; d = .32, p < .001). Deprivation modestly increased consummatory and anticipatory anhedonia directed toward sexual rewards (ds = .09-.12, ps < .02), did not significantly change anhedonia toward food rewards, and decreased anhedonia directed toward psychoactive drug rewards (i.e., increased desire for and pleasure from drugs; ds = -.21 to -.19, ps < .001). Deprivation-induced changes in anhedonia were modestly correlated with other withdrawal symptoms (average |r|s = .04-.23) and were amplified among participants with higher nicotine dependence and lower positive affect-related traits (|β|s = .10-.12, ps < .01). Some dimensions of anhedonia may be genuine expressions of acute tobacco withdrawal in AA smokers. Applying multi-dimensional anhedonia conceptualizations might advance basic knowledge and treatment of tobacco use disorder, improve smoking cessation outcomes, and address tobacco-related health disparities facing AA smokers. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Personalized lifestyle advice alters affective reactivity to negative events in anhedonic young adults

BACKGROUND

Anhedonia is a common symptom of several disorders, but cost-effective treatments that focus on anhedonia specifically have been lacking. Therefore, personalized lifestyle advice has recently been investigated as a suitable means of enhancing pleasure and positive affect (PA) in young adults with anhedonia. This intervention provided individuals with a personalized lifestyle advice which was based on observed individual patterns of lifestyle behaviors and experienced pleasure in daily life. The present study extends this previous work by examining a potential mechanism of treatment success, affective reactivity.

METHODS

We explored changes in affective reactivity to events in daily life from pre- to post-intervention in a subclinical sample of young adults with anhedonia (N = 69). Using the Experience Sampling Method (ESM), participants answered questions on their activities, their pleasure levels, PA and negative affect (NA) before and after the intervention.

RESULTS

Multilevel analysis revealed that participants did not experience an altered affective reactivity to positive events after the intervention. The affective reactivity to negative events depended on the level of improvement in mean-PA after the lifestyle advice intervention.

LIMITATIONS

The present study used a subclinical sample with the majority of participants being female which limited the generalizability of the findings.

CONCLUSION

This study suggests that an altered affective reactivity to negative events is an underlying mechanism of the effectiveness of a personalized lifestyle advice.

Factor structure and sex invariance of the temporal experience of pleasure scale (TEPS) in Chinese university students and clinical population

BACKGROUND

A motivation dimension of the core psychiatric symptom anhedonia additional has been suggested. The Temporal Experience of Pleasure Scale (TEPS) has been reported to assess anticipatory and consummatory pleasure separately in multiple factor-structure models. This study explored the factor structure of a Chinese version of the 18-item TEPS and further explored the measurement invariance of the TEPS across sex and clinical status (non-clinical, psychiatric).

METHODS

Best-fit factor structure of the TEPS was examined in a non-clinical cohort of 7410 undergraduates, randomized into sample 1 (N = 3755) for exploratory factor analysis (EFA) and sample 2 (N = 3663) for confirmatory factor analysis (CFA). Additionally, serial CFA was conducted to evaluate measurement invariance across sex and between clinical (N = 313) and non-clinical (N = 341) samples.

RESULTS

EFA supported a new four-factor structure with a motivation component, based on the original two-factor model (consummatory pleasure with/without motivation drive, anticipatory pleasure with/without motivation drive). CFA confirmed the four-factor model as the best-fit structure and revealed a second-order hierarchy in non-clinical and clinical samples. Full scalar invariance was observed across clinical and non-clinical samples and across sex in the clinical sample; only partial scalar invariance was observed across sex in the non-clinical sample.

CONCLUSIONS

A four-factor structured TEPS can assess motivation-driving dimensions of anticipatory and consummatory pleasure, consistent with the recently advanced multidimensional structure of anhedonia. CFA and measurement invariance results support application of the TEPS for assessing motivation aspects of anhedonia.

Inflammatory cytokines, complement factor H and anhedonia in drug-naïve major depressive disorder

OBJECTIVE

Anhedonia is a core symptom of major depressive disorder (MDD) and often associated with poor prognosis. The main objective of the present study was to explore the relationship between complement factor H (CFH), inflammatory cytokines and anhedonia in drug-naïve MDD patients.

METHODS

A total of 215 participants (61 MDD patients with anhedonia, 78 MDD patients without anhedonia, and 76 control subjects) were included. Severity of depression and levels of anhedonia were evaluated by Hamilton Rating Scale for Depression-17 (HAMD-17) and SHAPS (Snaith-Hamilton Pleasure Scale). Plasma levels of CFH, interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α) were measured.

RESULTS

The plasma levels of CFH, IL-10 and TNF-α were higher in drug-naïve MDD patients than control subjects. Compared to MDD patients without anhedonia, patients with anhedonia showed higher levels of CFH and IL-6. The stepwise regression analysis revealed that IL-10, TNF-α, as well as IL-10 × TNF-α were associated with depressive symptoms measured by HAMD-17 in drug-naïve MDD patients, while only CFH levels were identified as a mediator factor for the severity of anhedonia in the patients.

CONCLUSION

MDD patients with anhedonia showed different inflammatory characteristics compared to patients without anhedonia. Our results provide novel evidence suggesting that increased plasma CFH levels may be a potential biomarker of anhedonia of subtyping MDD.

Knockout of the Serotonin Transporter in the Rat Mildly Modulates Decisional Anhedonia

Serotonin transporter gene variance has long been considered an essential factor contributing to depression. However, meta-analyses yielded inconsistent findings recently, asking for further understanding of the link between the gene and depression-related symptoms. One key feature of depression is anhedonia. While data exist on the effect of serotonin transporter gene knockout (5-HTT^-/-) in rodents on consummatory and anticipatory anhedonia, with mixed outcomes, the effect on decisional anhedonia has not been investigated thus far. Here, we tested whether 5-HTT^-/- contributes to decisional anhedonia. To this end, we established a novel touchscreen-based go/go task of visual decision-making. During the learning of stimulus discrimination, 5-HTT^+/+ rats performed more optimal decision-making compared to 5-HTT^-/- rats at the beginning, but this difference did not persist throughout the learning period. During stimulus generalization, the generalization curves were similar between both genotypes and did not alter as the learning progress. Interestingly, the response time in 5-HTT^+/+ rats increased as the session increased in general, while 5-HTT^-/- rats tended to decrease. The response time difference might indicate that 5-HTT^-/- rats altered willingness to exert cognitive effort to the categorization of generalization stimuli. These results suggest that the effect of 5-HTT ablation on decisional anhedonia is mild and interacts with learning, explaining the discrepant findings on the link between 5-HTT gene and depression.

Possible New Symptoms of Tobacco Withdrawal III: Reduced Positive Affect-A Review and Meta-analysis

INTRODUCTION

Most descriptions of tobacco withdrawal have not changed in >30 years despite new research. This meta-analysis tested whether abstinence leads to decreased positive affect (PA) because abstinence-induced symptom changes are a core feature of the tobacco withdrawal syndrome. In addition, we examined whether reduced PA was due to withdrawal (ie, temporary decrease in a "U-shaped" curve) or offset (ie, return to baseline) effect.

METHODS

Our main inclusion criterion was a prospective within-participant test of change in PA during abstinence conditions among people who smoke cigarettes daily who were not using a cessation medication. Our search of PubMed, PsycINFO, and personal libraries yielded a total of 32 tests with 2054 participants.

RESULTS

There was a medium effect size indicating an overall decrease in PA following abstinence from cigarettes (Cohen's d = -0.40, 95% CI = -0.30 to -0.49). There was large heterogeneity (I2 = 70.7%). Most (79%) of the 24 trials that conducted significance tests reported that reduction in PA was significant. Seven tests were adequately designed to detect a withdrawal versus offset effect. Over half (57%) displayed a U-shaped curve for abstinence-induced change in PA indicative of a withdrawal symptom rather than offset effect.

CONCLUSIONS

Abstinence from cigarettes is associated with a decrease in PA. Whether low PA should be added to withdrawal measures and diagnostic criteria requires replication of the time-course of change in PA and tests of whether abstinence-induced changes in PA and negative affect occur independently.

IMPLICATIONS

Though there was substantial heterogeneity among trials, our findings suggest that (1) abstinence from cigarettes decreases positive affect and (2) this decrease may represent a withdrawal effect (vs. an offset effect). However, it is unclear whether abstinence-induced losses in positive affect are independent from increased negative affect.

Exploring Anhedonia in Kennelled Dogs: Could Coping Styles Affect Hedonic Preferences for Sweet and Umami Flavours?

Simple Summary

Kennelled dogs are susceptible to suffer chronic stress when social interactions with conspecifics and spatial needs are long-term restricted. Chronic stress may affect pleasure perception of food and solutions in dogs as observed in several animals, a phenomenon known as anhedonia. However, little information exists on how different coping styles could prevent the onset of anhedonia. Fourteen kennelled Beagle dogs were used to study the acceptability and preference for different dilute palatable sucrose and monosodium glutamate (MSG) solutions. Coping style of animals was previously evaluated through a modified human-approach test. This test consisted in assessing whether or not dogs approached an unfamiliar human when a feeding opportunity was presented, classifying them as close dogs (CD; proactive) or distant dogs (DD; reactive) respectively. It was observed that DD presented a lower intake of both sucrose and MSG dilute solutions compared with CD. Moreover, DD exhibited a higher consumption of MSG than CD at the highest concentrations, supporting that their intake depends on solution palatability. Finally, DD did not prefer sucrose or MSG solutions over water at any dilute solution offered. Together, these results suggest that dogs that are categorized as reactive animals could diminish their ability to perceive dilute palatable solutions reflecting depressive-like behaviours such as anhedonia.

Abstract

Kennelled dogs are at risk of suffering chronic stress due to long-term spatial, social and feeding restrictions. Chronic stress may decrease the dogs’ capacity to feel pleasure when facing hedonic experiences, modifying their perception for palatable ingredients. However, different abilities to cope with environmental stressors could prevent the onset of anhedonia. Fourteen kennelled Beagle dogs were used to study the acceptability and preference for different dilute sucrose and monosodium glutamate (MSG) solutions. Coping style of animals was previously evaluated through a human approach test (HAT) and classified as close dogs (CD; proactive) or distant dogs (DD; reactive) according to whether or not they approached an unfamiliar human when a feeding opportunity was presented. Consumption results were analysed taking into account the sucrose/MSG concentrations, HAT (CD or DD), age, and weight of the animals. DD presented a lower intake of sucrose (p = 0.041) and MSG (p = 0.069) solutions compared with CD. However, DD exhibited a higher consumption of MSG than CD at its highest concentrations, supporting that their intake depends on solution palatability. Finally, DD did not prefer sucrose or MSG solutions over water at any dilute solution offered. Together, these results suggest that dogs that are categorized as reactive animals could diminish their ability to perceive dilute palatable solutions, reflecting depressive-like behaviours as anhedonia.

Disentangling fatigue from anhedonia: a scoping review

Fatigue and anhedonia are commonly reported, co-occurring clinical symptoms associated with chronic illnesses. Fatigue is a multidimensional construct that is defined as a distressing, persistent, subjective sense of physical, cognitive, or emotional tiredness that interferes with usual functioning. Anhedonia is a component of depressive disorders and other psychiatric conditions, such as schizophrenia, and is defined by the reduced ability to experience pleasure. Both symptoms greatly affect the health-related quality of life of patients with chronic illnesses. Although fatigue and anhedonia are commonly associated with each other, understanding the differences between the two constructs is necessary for diagnosis and clinical treatment. A scoping review was conducted based on published guidance, starting with a comprehensive search of existing literature to understand the similarities and differences between fatigue and anhedonia. An initial search of PubMed using fatigue and anhedonia as medical subject headings yielded a total of 5254 articles. A complete full-text review of the final 21 articles was conducted to find articles that treated both constructs similarly and articles that presented fatigue and anhedonia as distinct constructs. About 60% of the reviewed articles consider both constructs as distinct, but a considerable number of the reviewed articles found these constructs indistinguishable. Nomenclature and biology were two themes from the reviewed articles supporting the idea that anhedonia and fatigue are indistinguishable constructs. The information generated from this review is clinically relevant to optimize the management of fatigue related to anhedonia from other fatigue subtypes.

Dissociating self-generated volition from externally-generated motivation

Insight into motivational processes may be gained by examining measures of willingness to exert effort for rewards, which have been linked to neuropsychiatric symptoms of anhedonia and apathy. However, while much work has focused on the development of models of motivation based on classic tasks of externally-generated levels of effort for reward, there has been less focus on the question of self-generated motivation or volition. We developed a task that aims to capture separate measures of self-generated and externally-generated motivation, with two task variants for physical and cognitive effort, and sought to test and validate this measure in two populations of healthy volunteers (N = 27 and N = 28). Similar to previous reports, a sigmoid function represented a better overall fit to the effort-reward data than a linear or Weibull model. Individual sigmoid function shapes were governed by two free parameters: bias (the amount of reward needed for effort initiation) and reward insensitivity (the amount of increase in reward needed to accelerate effort expenditure). For both physical and cognitive effort, bias was higher in the self-generated condition, indicating reduced self-generated volitional effort initiation, compared to externally-generated effort initiation, across effort domains. Bias against initial effort initiation in the self-generated condition was related to a specific dimensional measure of anticipatory anhedonia. For physical effort only, reward insensitivity was also higher in the self-generated condition compared to the externally-generated motivation condition, indicating lower self-generated effort acceleration. This work provides a novel objective measure of self-generated motivation that may provide insights into mechanisms of anhedonia and related symptoms.

Developmental antecedents of social anhedonia: The roles of early temperament and sex

Social anhedonia is well established as a transdiagnostic factor, but little is known about its development. This study examined whether temperament and parenting in early childhood predict social anhedonia in early adolescence. We also explored whether the relationships between early predictors and social anhedonia are moderated by a child's sex. A community sample of children participated in laboratory observations of temperament and parenting practices at age 3 (n = 275). The participants returned at age 12 and completed the Anticipatory and Consummatory Interpersonal Pleasure Scale-Child Version (ACIPS-C). Our results indicated that, at age 3, lower observed sociability predicted higher levels of social anhedonia at age 12. These associations were moderated by child sex, such that males with diminished sociability reported greater social anhedonia. These findings indicate that predictors of early adolescent social anhedonia are evident as early as 3 years of age. However, these effects were evident only for males, suggesting that the pathways to social anhedonia in early adolescence differ as a function of sex.

Psychosocial factors and multiple health risk behaviors among early adolescents: a latent profile analysis

Early adolescence is a pivotal developmental period when multiple health risk behaviors, such as obesity and substance use, are often established. Several psychosocial factors, often considered traits, have been independently associated with these increases, including executive function (EF), mindfulness disposition (MD), perceived stress, distress tolerance (DT), and anhedonia. However, these factors have not been evaluated for their conjoint relationships to determine whether different patterns may signal greater or lesser risk for obesity and substance use, and whether the same patterns relate to obesity and substance use in the same ways (same magnitude of risk). To evaluate these patterns, a latent profile analysis was conducted, resulting in a three-profile model. Profile 1 (8% of sample) was characterized by the lowest levels of EF, MD, DT and highest levels of stress and anhedonia, profile 2 (44%) intermediate levels, and profile 3 (48%) the highest levels of EF, MD, DT and lowest levels of stress and anhedonia. Youth classified to profile 1 reported significantly greater levels of both obesogenic and substance use behaviors relative to other profiles. Findings suggest that adolescents engaging in obesogenic and substance use behaviors may share common profiles of psychosocial risk.

Possible New Symptoms of Tobacco Withdrawal II: Anhedonia-A Systematic Review

INTRODUCTION

When animals undergo nicotine deprivation, rewards become less rewarding (ie, anhedonia occurs). We searched for tests of whether anhedonia occurs in abstinent smokers.

METHODS

The major inclusion criterion was a within-participants comparison of behavioral measures of reward sensitivity or self-reported anhedonia during smoking versus during abstinence among daily smokers. A computerized search of PubMed, PsychInfo, and Cochrane databases and other methods located 13 studies. All but one were laboratory studies.

RESULTS

The number of studies and participants were small and the results mixed. In terms of anticipatory anhedonia (ie, wanting a reward), abstinence appeared to decrease willingness to work for immediately available rewards, but did not appear to influence how much adding rewards to a task increased responding. Abstinence also appeared to produce small increases in self-reported anticipatory anhedonia. In terms of consummatory anhedonia (ie, liking a reward), self-report measures found anhedonia decreased pleasure from rewards in some but not all tests. In terms of learning (ie, learning to choose a more frequent reward), abstinence did not reliably decrease allocating responding to high versus low frequency reward options.

CONCLUSIONS

Although results were mixed, abstinence appears to increase anticipatory anhedonia. It is unclear if abstinence increases consummatory or reward learning-based anhedonia. Further studies of anhedonia in clinical settings are needed (1) to estimate the reliability and clinical significance of anhedonia as a symptom of tobacco withdrawal, (2) to assess if effects represent withdrawal versus offset processes, and (3) to assess if anhedonia interferes with the ability to stop smoking.

IMPLICATIONS

Anticipatory anhedonia appears to be a symptom of tobacco withdrawal and should be added to tobacco withdrawal checklists and diagnostic criteria. Further study of consummatory and learning-based anhedonia is warranted.

[Angedonia in the structure of affective disorders: therapeutic opportunities]

Anhedonia is one of the core features of depression. The article considers the place of anhedonia in the structure of affective disorders, its influence on the prognosis and effectiveness of therapy. The authors stress that various manifestations of anhedonia must be considered in correlation with the basic ability to feel pleasure. Therapy of anhedonia is not always effective. According to literature, agomelatin occupies a leading position among the drugs that reduce anhedonia.

Anhedonia as a key clinical feature in the maintenance and treatment of opioid use disorder

There is a critical need for research on clinical features that may influence response to treatment for opioid use disorder (OUD). Given its neurobiology and relevance to opioid use, anhedonia may be one such promising clinical feature. We identified and reviewed 11 studies that measured anhedonia in humans with OUD to characterize the current state of evidence and highlight potential implications for treatment. The majority of studies were cross-sectional, indicating higher anhedonia scores in opioid-dependent samples compared to healthy controls. Rates of participants with clinically significant anhedonia ranged from 21% to 48%. Anhedonia scores were correlated with opioid craving and use, however there are significant knowledge gaps regarding its time course and impact on treatment adherence and outcomes. Repeated assessment of anhedonia early in treatment for OUD is recommended, as it may be a unique predictor of dropout or non-response, and a potential target for behavioral and/or pharmacological intervention.

Pharmacological interventions targeting anhedonia in patients with major depressive disorder: A systematic review

Anhedonia is defined as a diminished ability to experience interest or pleasure, and is a critical psychopathological dimension of major depressive disorder (MDD). The purpose of the current systematic review is to evaluate the therapeutic efficacy of pharmacological treatments on measures of anhedonia in adults with MDD. Electronic databases Cochrane Library (CENTRAL), Ovid MEDLINE, PubMed, PsycINFO, and Google Scholar were searched from inception to June 1, 2018 for longitudinal studies utilizing pharmacotherapy for the treatment of anhedonia in patients with MDD. A total of 17 eligible studies were identified (i.e., evaluated the effects of pharmacotherapy on a measure of anhedonia). Among the identified studies, the efficacy of 14 different pharmacotherapies on measures of anhedonia were evaluated, including melatonergic agents (i.e. agomelatine), monoaminergic agents (i.e. moclobemide, clomipramine, bupropion, venlafaxine, fluoxetine, amitifadine and levomilnacipran, escitalopram, and sertraline), glutamatergic agents (i.e., ketamine and riluzole), stimulants (i.e., methylphenidate), and psychedelics (i.e., psilocybin). Based on the available evidence, most antidepressants demonstrated beneficial effects on measures of anhedonia as well as the other depressive symptoms. Only escitalopram/riluzole combination treatment was ineffective in treating symptoms of anhedonia in MDD. Continued research is warranted to further support the efficacy of mechanistically-distinct antidepressants in treating symptoms of anhedonia in MDD. Future research should also aim to parse out the heterogeneous effects of different pharmacotherapies on anhedonic symptoms.

Conceptualizing anhedonias and implications for depression treatments

Anhedonia has been implicated as a core symptom of depression and schizophrenia, and studying anhedonia has yielded a wide array of important findings aiding the understanding and identification of psychological disorders. However, anhedonia is a complex and multifaceted construct; indeed, the term anhedonia has been defined in psychological and psychiatric research as many different concepts, a number of which are theoretically and methodologically independent of one another. In this review alone, we discuss research that separates social aspects of anhedonia from the physical contexts of anhedonia, with the former emphasizing interpersonal relationships as important to anhedonic symptoms, and the latter emphasizing biological and brain-related impairment as potential causes of chronic anhedonia states. We highlight research that distinguishes between interest in (wanting) or experience of (liking) potential pleasure as definitions of anhedonia and also disambiguate methodologically and theoretically distinct ways of assessing 1) trait-level dispositional tendencies, 2) state-level cross-sectional assessments, and 3) symptom-based recent changes from baseline, all of which have been used to indicate anhedonia. Lastly, we describe cutting-edge translations of basic anhedonia research into treatment and discuss how different conceptualizations of anhedonia, guided by recent theoretical and methodological advances, have begun to usher in a science of anhedonia that is consistent with increasingly personalized assessment and treatment. We conclude with a note for future research, emphasizing that continued application of theoretically based operationalizations of anhedonia and sound design are paramount to continue the recent progress toward meaningful and specific use of the anhedonia construct in clinical research.

The Measurement of Positive Valence Forms of Empathy and Their Relation to Anhedonia and Other Depressive Symptomatology

Construct validity of a brief self-report measure of "positive-valence empathy" (the tendency to exude positive emotion as a means to stimulate positive affect in others, and/or to vicariously share in another's positive emotion; Light et al., 2009) was attained utilizing a sample of 282 healthy adults. Positive-valence empathy may have unique predictive ability for differentiating depression versus depression with anhedonia. Confirmatory factor analyses revealed a two-factor structure for the final 15-item Light-Moran Positive Empathy Scale (PES), with an 8-item "Empathic Happiness" subscale (e.g., "I find that other people's happiness easily rubs off on me") and a 7-item "Empathic Cheerfulness" subscale (e.g., "I enjoy making others feel good"). "Empathic Happiness" was a significantly better predictor of overall depressive symptomatology (Beck et al., 1996) than anhedonia (Snaith et al., 1995). The Light-Moran PES-15 may have real-world impact and predictive utility for well-being.

Anhedonia in irritable bowel syndrome and in inflammatory bowel diseases and its relationship with abdominal pain

BACKGROUND

Anhedonia is the lowered ability to experience pleasure from rewarding or enjoyable activities and is considered a symptom of depression. Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are frequently accompanied by psychiatric disorders such as depression. However, to our knowledge, studies have yet to investigate the anhedonia in these patients. Our aim was to study the level of anhedonia in patients with IBD and IBS in comparison with healthy controls (HC), and to relate anhedonia levels with the severity of abdominal pain.

METHODS

We consecutively recruited IBD and IBS patients. All patients fulfilled the Snaith-Hamilton Pleasure Scale (SHAPS), a self-rating scale consisting of 14 items that cover the domains of social interaction, food, and drink, sensory experiences, achievement and pastimes, and the Beck Depression Inventory-II (BDI-II) to screen for depression. Moreover, we calculated abdominal pain on a (0-100) Visual Analog Scale (VAS) in all patients.

KEY RESULTS

We enrolled 120 patients (64 IBD and 56 IBS) and 81 HC. Among IBD patients, 34 had Crohn's disease and 30 ulcerative colitis. All patients as a whole had significantly higher SHAPS and BDI-II scores than HC (1.3 ± 1.5 vs 0.8 ± 0.1; P = 0.01 and 10.4 ± 7.5 vs 5.9 ± 4.9; P < 0.001, respectively), while no significant differences were found among groups. SHAPS score showed a significant correlation in only a few statements of BDI-II. In our cohort, a multivariate regression analysis showed that SHAPS score was significantly related to current abdominal pain (0-100 VAS) (P = 0.03) independent of gender and age.

CONCLUSIONS AND INFERENCES

The level of anhedonia was higher in all patients compared to healthy controls. The more the subject is anhedonic, the higher the VAS scale for abdominal pain. This study suggests that anhedonia would need to be very carefully weighed in IBD and IBS patients.

Spanish adaptation of the Dimensional Anhedonia Rating Scale (DARS)

BACKGROUND

Anhedonia is defined as the lack of enjoyment, engagement in, or energy for life's experiences. Only two scales to measure anhedonia have been adapted for use in Spanish-speaking populations. The aim of this study was to determine the reliability and validity of the Dimensional Anhedonia Rating Scale (DARS) following translation and adaptation for Spanish population.

METHOD

The study sample included 134 patients over 18 years of age with a range of psychiatric diagnoses. Those with substance use, decompensated medical conditions, illiteracy, or lack of fluency in Spanish were excluded. The structure of the Spanish adaptation was evaluated through factor analysis. Internal reliability was assessed through Cronbach's alpha and validity was measured using Pearson's correlation between total scores for DARS and its subscales and SHAPS score.

RESULTS

A strong internal consistency was observed (Cronbach alpha = 0.92 for total scale score and 0.91-0.92 for subscale scores). Similarly, a significant and strong correlation between total scores for DARS and SHAPS was found (r = 0.51, p < 0.01).

LIMITATIONS

The heterogeneous distribution of diagnoses included in the study may limit our results.

CONCLUSIONS

The Spanish DARS maintains the psychometric properties of the original questionnaire, with strong internal consistency and adequate validity. DARS is a specific questionnaire for evaluating anhedonia, incorporating elements that reflect motivation, interest, and effort, and one which offers possible advantages over other anhedonia scales.

Predicting Predischarge Anhedonia Among Inpatients With Schizophrenia and Schizoaffective Disorders: A Large-scale Analysis

This study sought to evaluate predischarge anhedonia level and its predictors in 125 inpatients with schizophrenia and schizoaffective disorders. Consecutively admitted inpatients were assessed before discharge from the hospital using the Specific Loss of Interest and Pleasure Scale (SLIPS) and a battery of measures for clinical and psychosocial variables. When symptoms, distress, and social anhedonia scores were controlled, the SLIPS score inversely correlated with self-constructs, social support, quality of life, recovery, and unmet needs. Using two cutoff points of the data set of SLIPS, we identified three groups: 19 (15.2%) patients reported "no loss of pleasure"; 46 (36.8%), "some loss of pleasure"; and 60 (48.0%), "marked diminishment of pleasure." The SLIPS score is predicted by sensitivity, unmet needs, deficient interpersonal pleasure, poor quality of life, and friend support. The study underlines the importance of assessing anhedonia and related psychosocial factors in patients with serious mental illness.

A randomized controlled double-blind clinical trial comparing versus placebo the effect of an edible algal extract (Ulva Lactuca) on the component of depression in healthy volunteers with anhedonia

BACKGROUND

The effects of the seaweed extract were evaluated on the animal model equivalent of depression compared with a control group treated with the carrier (spring water) and a reference group treated with Imipramine and showed significative effect. This clinical trial was intended to confirm in humans the potential efficacy identified in animals. The primary objective was to compare against a placebo the effect of Ulva L.L extract in healthy volunteers whose anhedonia was characterized by a component of depression.

METHODS

Single-centre double-blind randomized placebo-controlled clinical trial on parallel arms of two groups of 45 subjects. The study could include men or women aged 18 to 65 years with anhedonia characterized by a Snaith Hamilton Pleasure Scale score (SHAPS) of ≥5 and feeling low morale for at least four weeks characterized by a component of depression evaluated on the Quick Inventory of Depressive Symptomatology - Self Report (QIDS-SR). Evaluation criteria: QIDS-SR; Patient Global Improvement Impression (PGII) and Clinical Global Improvement Impression (CGII).

RESULTS

86 subjects were included in the trial: 42 in the placebo group and 44 Ulva group. At D84, QIDS-SR significantly decreased more in the Ulva.L.L. group than in the placebo group (p: 0.0389). This difference is essentially linked to an improvement of the sleep disorders (p: 0.0219), of the psychomotor consequences (p: 0.002) and of the nutrition behaviour (p: 0.0694). 90.1% have the feeling of being improved in the Ulva group vs 72.5% in the placebo group (p: 0.0114) and in parallel 90.9% of the practitioners have the feeling that the subject has improved vs 70.8% (p: 0.0214).

CONCLUSION

This double-blind randomized placebo-controlled trial shows that daily intake for three months of a water-soluble extract of Ulva L.L. continues to significantly improve the component of depression of subjects presenting anhedonia compared with a placebo.

TRIAL REGISTRATION

Trial retrospectively registred on ClinicalTrial.gov under ID: NCT03545399 Date: 05/22/2018.

Assessment of Snaith-Hamilton Pleasure Scale (SHAPS): the dimension of anhedonia in Italian healthy sample

The Snaith-Hamilton Pleasure Scale (SHAPS) is a rapid screening battery created for assessing the presence of anhedonia, namely the inability to experience pleasure. Although, this symptom has widely been investigated in clinical settings, individual differences in anhedonia are also present in healthy population. The aim of present study was to validate the translated Italian version of this test. One thousand six hundred ninety-seven consecutive healthy subjects (55% female) of different ages (age 18-82 years) underwent SHAPS. Participants who showed mild level of anhedonia also completed the Apathy Evaluation Scale (AES), Beck Depression Inventory (BDI), Toronto Alexithymia Scale-20 (TAS), Mood Disorders Insight Scale (MDIS), and Beck Hopelessness Scale (BHS). The SHAPS showed good internal consistency and discriminant validity; moreover, the factorial analysis highlighted that SHAPS had a three-factor structure for explaining the anhedonic construct. 14.9% showed a significant reduction of hedonic tone (SHAPS ≥ 3). Finally, the degree of anhedonia was significantly correlated with BDI and BHS scores, but not with age or gender. Although anhedonia is a prominent feature of many psychiatric and neurological disorders, the presence of this symptom in the healthy population highlighted the importance to develop reliable tool. SHAPS shows good psychometric properties to assess multidimensional anhedonia symptoms also in Italian healthy population.

Development of a Self-Report Measure of Reward Sensitivity:A Test in Current and Former Smokers

Introduction

Tobacco use or abstinence may increase or decrease reward sensitivity. Most existing measures of reward sensitivity were developed decades ago, and few have undergone extensive psychometric testing.

Methods

We developed a 58-item survey of the anticipated enjoyment from, wanting for, and frequency of common rewards (the Rewarding Events Inventory-REI). The current analysis focuses on ratings of anticipated enjoyment. The first validation study recruited current and former smokers from Internet sites. The second study recruited smokers who wished to quit and monetarily reinforced them to stay abstinent in a laboratory study and a comparison group of former smokers. In both studies, participants completed the inventory on two occasions, 3-7 days apart. They also completed four anhedonia scales and a behavioral test of reduced reward sensitivity.

Results

Half of the enjoyment ratings loaded on four factors: socializing, active hobbies, passive hobbies, and sex/drug use. Cronbach's alpha coefficients were all ≥0.73 for overall mean and factor scores. Test-retest correlations were all ≥0.83. Correlations of the overall and factor scores with frequency of rewards and anhedonia scales were 0.19-0.53, except for the sex/drugs factor. The scores did not correlate with behavioral tests of reward and did not differ between current and former smokers. Lower overall mean enjoyment score predicted a shorter time to relapse.

Discussion

Internal reliability and test-retest reliability of the enjoyment outcomes of the REI are excellent, and construct and predictive validity are modest but promising. The REI is comprehensive and up-to-date, yet is short enough to use on repeated occasions. Replication tests, especially predictive validity tests, are needed.

Implications

Both use of and abstinence from nicotine appear to increase or decrease how rewarding nondrug rewards are; however, self-report scales to test this have limitations. Our inventory of enjoyment from 58 rewards appears to be reliable and valid as well as comprehensive and up-to-date, yet is short enough to use on repeated occasions. Replication tests, especially of the predictive validity of our scale, are needed.

Considerations on nonclinical approaches to modeling risk factors of suicidal ideation and behavior

Given the serious nature of suicidal ideation and behavior (SIB) and the possibility of treatment-emergent SIB, pharmaceutical companies are now applying more proactive approaches in clinical trials and are considering the value of nonclinical models to predict SIB. The current review summarizes nonclinical approaches to modeling three common risk factors associated with SIB: aggression, impulsivity, and anhedonia. For each risk factor, a general description, advantages and disadvantages, species considerations, nonclinical to clinical translation, and pharmacological validation with respect to treatments associated with SIB are summarized. From this review, several gaps were identified that need to be addressed before use of these nonclinical models can be considered a viable option to predict the relative risk for SIB. Other future directions that may compliment these nonclinical approaches, including the use of selectively-bred or genetically-modified rodent models, transgenic models, gene expression profiling, and biomarker analysis, are discussed. This article was developed with the support of the DruSafe Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ, www.iqconsortium.org).

Social defeat-induced anhedonia: effects on operant sucrose-seeking behavior

Reduced capacity to experience pleasure, also known as anhedonia, is a key feature of the depressive state and is associated with poor disease prognosis and treatment outcome. Various behavioral readouts (e.g., reduced sucrose intake) have been employed in animal models of depression as a measure of anhedonia. However, several aspects of anhedonia are poorly represented within the repertoire of current preclinical assessments. We recently adopted the social defeat-induced persistent stress (SDPS) paradigm that models a maintained depressive-like state in the rat, including social withdrawal and deficits in short-term spatial memory. Here we investigated whether SDPS elicited persistent deficits in natural reward evaluation, as part of anhedonia. We examined cue-paired operant sucrose self-administration, enabling us to study acquisition, motivation, extinction, and relapse to sucrose seeking following SDPS. Furthermore, we addressed whether guanfacine, an α2-adrenergic agonist that reduces stress-triggered maladaptive behavioral responses to drugs of abuse, could relief from SDPS-induced anhedonia. SDPS, consisting of five social defeat episodes followed by prolonged (≥8 weeks) social isolation, did not affect sucrose consumption during acquisition of self-administration. However, it strongly enhanced the motivational drive to acquire a sucrose reward in progressive ratio training. Moreover, SDPS induced initial resilience to extinction and rendered animals more sensitive to cue-induced reinstatement of sucrose-seeking. Guanfacine treatment attenuated SDPS-induced motivational overdrive and limited reinstatement of sucrose seeking, normalizing behavior to control levels. Together, our data indicate that long after the termination of stress exposure, SDPS induces guanfacine-reversible deficits in evaluation of a natural reward. Importantly, the SDPS-triggered anhedonia reflects many aspects of the human phenotype, including impaired motivation and goal-directed conduct.

Serotonin transporter clustering in blood lymphocytes predicts the outcome on anhedonia scores in naïve depressive patients treated with antidepressant medication

BACKGROUND

We have shown that serotonin transporter (SERT) clustering in blood lymphocytes is altered in major depression and correlates with pharmacological therapeutic responses measured with the Hamilton scale. In the present report, we extend these results to the self-assessment anhedonia scale, as anhedonia is a cardinal symptom of major depression that is difficult to treat with first-line antidepressants.

METHODS

We collected blood samples from 38 untreated depression patients at the time of enrolment and 8 weeks after pharmacological treatment. We used the self-assessment anhedonia scale to evaluate anhedonia symptoms before and after treatment. We also used quantitative immunocytochemistry to measure SERT clusters in blood lymphocytes.

RESULTS

Evaluation of the distribution of SERT clusters size in the plasma membrane of lymphocytes identified two subpopulations of naive depression patients: Depression I (D-I) and Depression II (D-II). While naïve D-I and D-II patients initially showed similar anhedonia scores, D-II patients showed a good response in anhedonia symptoms after 8 weeks of psychopharmacological treatment, whereas D-I patients failed to show any improvement. Psychopharmacological treatment also induced an increase in the number of SERT clusters in lymphocytes in the D-II group, and this increase correlated with the improvement in anhedonia symptoms.

CONCLUSIONS

SERT clustering in peripheral lymphocytes can be used to identify patient response to antidepressant therapy as ascertained by anhedonia scores.

Anhedonia in depressed patients on treatment with selective serotonin reuptake inhibitor anti-depressant--A two-centered study in Malaysia

OBJECTIVE

Anhedonia is the reduced ability to experience pleasure. It is a core symptom of depression and is particularly difficult to treat. This study aims to compare the level of anhedonia between depressed patients on anti-depressants and healthy subjects.

METHOD

A total of 111 depressed patients on selective serotonin reuptake inhibitor (SSRI) and 82 healthy subjects were recruited from the outpatient psychiatric services at two major general hospitals in a cross-sectional study. Subjects were assessed using the Mini International Neuropsychiatric Interview 5.0.0 or MINI, Beck's Depression Index (BDI), and Snaith-Hamilton Pleasure Scale (SHAPS). Relevant personal and sociodemographic information were also collected.

RESULTS

There was a significant association between educational level and SHAPS-M scores (P < 0.01) among the participants. Most items in the SHAPS scores were significantly different (P < 0.01) in the depressed subjects treated with anti-depressant compared with the healthy subjects, after adjusting the confounding factors, BDI score, and educational level.

CONCLUSION

Anhedonia often persists in depressed patients despite on SSRI anti-depressant treatment.