Assessing anhedonia in psychiatric patients

Pretreatment anhedonia as a predictor of exposure-based anxiety treatment outcomes

Reward processes can reinforce extinction learning and aide cognitive processes involved with inhibitory learning. Anhedonia, characterized by deficits in reward incentivization, hedonic response, and learning, may therefore predict worse treatment outcomes. The current study examined associations between pretreatment self-reported anhedonia and several measures of anxiety symptom severity and treatment outcomes in a naturalistic exposure-based treatment setting. We used multilevel models to examine the relationship between pretreatment anhedonia with change in general treatment response and disorder-specific symptoms for obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic disorder (PD). Consistent with hypotheses, pretreatment anhedonia severity was associated with higher pretreatment anxiety symptom severity across all measures. However, inconsistent with hypotheses, higher anhedonia scores were associated with greater symptom improvement across treatment for OCD, GAD, and PD, and had no significant relationships with diagnosis-general outcome measures, PTSD symptoms, or SAD symptoms. In sensitivity analyses including number of sessions, higher anhedonia was associated with more sessions across treatment and anhedonia no longer significantly predicted OCD or GAD treatment outcomes when controlling for treatment dose. Together, findings suggest that individuals with higher pretreatment anhedonia still respond to exposure therapy for anxiety disorders, but may require more sessions. More broadly, results highlight challenges in translating laboratory research to naturalistic clinical settings and the need for intensive longitudinal studies that can assess the role of reward processes in exposure therapy.

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

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

Establishing content validity of the Dimensional Anhedonia Rating Scale

BACKGROUND

This study was designed to evaluate content validity of the Dimensional Anhedonia Rating Scale (DARS), a patient-reported outcome measure, in adults with anhedonia in the context of major depressive disorder (MDD). To accomplish this, a conceptual model including the symptoms and impacts of anhedonia in the context of MDD was developed and refined through a targeted literature review, clinician interviews (N = 6), and participant interviews (N = 20).

RESULTS

Using the final conceptual model, an item mapping exercise was conducted for the DARS, demonstrating that it provided suitable concept coverage in this population. Cognitive debriefing of the DARS with participants demonstrated that it was generally well understood and clear.

CONCLUSIONS

Overall, the study established that the DARS demonstrates content validity in adults with anhedonia in the context of MDD. Other measurement properties of the DARS will be evaluated in planned psychometric analyses.

L-type calcium channel blockade attenuates the anxiogenic-like effects of cocaine abstinence in female and male rats

Cocaine abstinence and withdrawal are linked to relapse and heightened anxiety. While L-type calcium channels (LTCCs) have been associated with cocaine use disorders in humans and drug-seeking in rodents, their role in mood-related symptoms during cocaine abstinence remains unclear. We addressed this by investigating the ability of LTCC blockade with isradipine to alter the mood-related behavioral phenotypes induced by cocaine abstinence. Female and male Sprague-Dawley rats were trained to self-administer cocaine or saline, followed by a 14-day period of abstinence. Subsequently, behavioral responses were examined using the sucrose preference test (SPT), elevated plus maze (EPM), and forced swim test (FST). Cocaine-abstinent rats showed decreased open arm time in the EPM and increased immobility time in the FST with no changes in the SPT. Isradipine (0.4 mg/kg or 1.2 mg/kg, i.p.), reversed the anxiogenic-like EPM behavior in female cocaine-abstinent rats, whereas only the higher dose (1.2 mg/kg, i.p.) was effective in male cocaine-abstinent rats. In the FST, the lower dose (0.4 mg/kg, i.p.) of isradipine reversed the increased immobility time observed in cocaine-abstinent female and male rats, with no isradipine effect in saline-abstinent rats. In contrast 1.2 mg/kg, i.p. isradipine decreased immobility time in both cocaine and saline abstinent female and male rats. In summary, isradipine administration reversed the anxiogenic and increased the FST immobility time associated with cocaine abstinence in a dose and sex-dependent manner. The data underscore the importance of further investigation of LTCC mechanisms and their therapeutic potential for mood disorders associated with cocaine use disorder.

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

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

Effect of antidepressants and social defeat stress on the activity of dorsal raphe serotonin neurons in free-moving animals

Major depressive disorder (MDD) is among the most common mental disorders worldwide and is characterized by dysregulated reward processing associated with anhedonia. Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for MDD; however, their onset of action is delayed. Recent reports have shown that serotonin neurons in the dorsal raphe nucleus (DRN) are activated by rewards and play a vital role in reward processing. However, whether antidepressant treatment affects the DRN serotonin neuronal response to rewards in awake animals remains unknown. In this study, we measured the activity of DRN serotonin neurons in awake mice and determined the effects of antidepressants and chronic stress on DRN serotonin neuronal activity. We found that acute treatment with citalopram, an SSRI, significantly decreased sucrose-induced activation of DRN serotonin neurons. The decrease in response to acute citalopram treatment was attenuated by chronic citalopram treatment. Acute treatment with (S)-WAY100135, a 5-HT1A receptor antagonist, dose-dependently inhibited the response to acute citalopram treatment. These results indicate that autoinhibition by activating 5-HT1A receptors via acute SSRI treatment may blunt the reward response, which can be recovered after chronic SSRI treatment.

Pleasurable emotions and internalizing psychopathology: A multi-study examination of specificity and alternative explanations

OBJECTIVES

Past research has been inconclusive regarding the specificity of associations between discrete pleasurable emotions and internalizing symptoms. Contentment may be especially relevant to depression, whereas tranquillity may be especially relevant to worry. The goal of the current research was to clarify the mixed findings regarding the relation between pleasure deficits and internalizing psychopathology.

METHODS

Participants from three samples (Total N = 757) completed alternative measures of depression and pleasurable emotions. Participants in Study 1 also completed a measure of anticipatory and consummatory pleasure, and close peers to a subset of participants (N = 64) reported their perceptions of participants' depression severity. Participants in Studies 2 and 3 also completed a measure of worry.

RESULTS

Across the three samples, contentment was significantly negatively associated with self-reported depression. This association could not be accounted for by tranquillity, cheerfulness, anticipatory pleasure, or consummatory pleasure. Contentment was also strongly negatively associated with peer-reported depression. Contentment was more strongly associated with depression than was cheerfulness. However, the strength of the association between contentment and depression relative to the strength of the association between tranquillity and depression depended on how contentment and depression were measured. Conversely, tranquillity was more strongly associated with worry than were contentment or cheerfulness.

CONCLUSIONS

This study provides further evidence of the potential importance of the role of contentment in depression and tranquillity in worry. It may be useful to attend to contentment when assessing and treating depression and to attend to tranquillity when assessing and treating elevated worry.

L-type calcium channel regulation of depression, anxiety and anhedonia-related behavioral phenotypes following chronic stress exposure

Exposure to chronic and unpredictable stressors can precipitate mood-related disorders in humans, particularly in individuals with pre-existing mental health challenges. L-type calcium channels (LTCCs) have been implicated in numerous neuropsychiatric disorders, as LTCC encoding genes have been identified as candidate risk factors for neuropsychiatric illnesses. In these sets of experiments, we sought to examine the ability of LTCC blockade to alter depression, anxiety, and anhedonic-related behavioral responses to chronic unpredictable stress (CUS) exposure in female and male rats. Rats first underwent either 21 days of CUS or no exposure to chronic stressors, serving as home cage controls (HCC). Then rats were examined for anhedonia-related behavior, anxiety and depression-like behavioral responses as measured by the sucrose preference test (SPT), elevated plus maze (EPM), and forced swim test (FST). CUS exposed females and males showed anhedonic and anxiogenic-like behavioral responses on the SPT and EPM, respectively, when compared to HCCs. In female and male rats, systemic administration of the LTCC blocker isradipine (0.4 mg/kg and 1.2 mg/kg, I.P.) attenuated the CUS-induced decrease in sucrose preference and reversed the CUS-induced decrease in open arm time. In the FST, systemic isradipine decreased immobility time across all groups, consistent with an antidepressant-like response. However, there were no significant differences in forced swim test immobility time between HCC and CUS exposed animals. Taken together, these data point to a role of LTCCs in the regulation of mood disorder-related behavioral phenotype responses to chronic stress exposure.

Development of a multivariate prediction model for antidepressant resistant depression using reward-related predictors

Introduction

Individuals with depression who do not respond to two or more courses of serotonergic antidepressants tend to have greater deficits in reward processing and greater internalizing symptoms, yet there is no validated self-report method to determine the likelihood of treatment resistance based on these symptom dimensions.

Methods

This online case-control study leverages machine learning techniques to identify differences in self-reported anhedonia and internalizing symptom profiles of antidepressant non-responders compared to responders and healthy controls, as an initial proof-of-concept for relating these indicators to medication responsiveness. Random forest classifiers were used to identify a subset from a set of 24 reward predictors that distinguished among serotonergic medication resistant, non-resistant, and non-depressed individuals recruited online (N = 393). Feature selection was implemented to refine model prediction and improve interpretability.

Results

Accuracies for full predictor models ranged from .54 to .71, while feature selected models retained 3-5 predictors and generated accuracies of .42 to .70. Several models performed significantly above chance. Sensitivity for non-responders was greatest after feature selection when compared to only responders, reaching .82 with 3 predictors. The predictors retained from feature selection were then explored using factor analysis at the item level and cluster analysis of the full data to determine empirically driven data structures.

Discussion

Non-responders displayed 3 distinct symptom profiles along internalizing dimensions of anxiety, anhedonia, motivation, and cognitive function. Results should be replicated in a prospective cohort sample for predictive validity; however, this study demonstrates validity for using a limited anhedonia and internalizing self-report instrument for distinguishing between antidepressant resistant and responsive depression profiles.

Using the Beck Depression Inventory to Assess Anhedonia: A Scale Validation Study

Anhedonia is central to several psychological disorders and a frequent target of psychosocial and pharmacological treatments. We evaluated the psychometric properties of two widely used anhedonia measures derived from the Beck Depression Inventory: a 3-item (BDI-Anh3) and a 4-item version (BDI-Anh4). We evaluated these measures in a large undergraduate sample, a community sample, and a clinical sample. Both the BDI-Anh3 and the BDI-Anh4 showed adequate internal consistency, with BDI-Anh4 performing somewhat better, across the three samples. Both measures showed good convergent and discriminant validity, even after controlling for shared variance with other items on the BDI. These findings indicate that both measures have sufficient reliability and validity to support their use by researchers and clinicians.

A Delphi consensus on clinical features, diagnosis and treatment of major depressive disorder patients with anhedonia amongst psychiatrists in the Asia-Pacific

Background

Anhedonia, a core diagnostic feature for major depressive disorder (MDD), is defined as the loss of pleasure and interest in daily activities. Its prevalence in MDD patients vary from 35 to 70%. Anhedonia in MDD negatively impacts functioning and is associated with treatment resistance and poorer prognosis for various clinical outcomes. Owing to its complexity, there remains considerable heterogeneity in the conceptualization, diagnosis and clinical management of anhedonia in MDD.

Methods

This modified Delphi panel was conducted to elicit expert opinion and establish consensus on concepts relating to clinical features, diagnosis and treatment of MDD with anhedonia (MDDwA) amongst psychiatrists in the Asia-Pacific region. Seven themes were covered. A three-stage process was adopted for consensus generation (two online survey rounds, followed by a moderated consensus meeting). Statements were developed based on a literature review and input from a steering committee of six regional experts. The panel included 12 psychiatrists practicing in Australia, China, Hong Kong, Japan, South Korea and Taiwan with ≥5 years of specialist clinical experience, including assessment or management of patients with MDDwA.

Results

Overall, consensus was achieved (median ≥8) on 89/103 statements (86%). About half of the statements (55/103, 53%) achieved consensus in Round 1, and 29/36 modified statements achieved consensus in Round 2. At the moderated consensus meeting, five modified statements were discussed by the steering committee and consensus was achieved on all statements (5/5). The findings highlighted a lack of clear and practical methods in clinical practice for assessing anhedonia in MDD patients and limited physician awareness of anhedonia in Asia-Pacific.

Conclusion

Insights from this Delphi consensus provide a reference point for psychiatrists in Asia-Pacific to optimize their strategies for personalized diagnosis and management of patients with MDDwA. Identification of distinct and clinically relevant subtypes in MDD may be valuable for guiding personalized diagnosis and management approaches, including type-specific therapies.

Relationships between experimental task and questionnaire measures of reward/punishment sensitivity in attention-deficit/hyperactivity disorder (ADHD): protocol for a scoping review

INTRODUCTION

One of the purported underlying causal mechanisms of attention deficit hyperactivity disorder (ADHD) is altered motivational processes. Questionnaires have been used to identify the characteristics of reward and punishment sensitivity in individuals with ADHD. However, these questionnaires were initially developed to measure individual traits related to anxiety (inhibitory) and impulsivity (approach) tendencies or differences in pleasure-seeking. These reward and punishment sensitivity questionnaires are useful but might not capture all relevant aspects of altered motivational processes in ADHD. The proposed scoping review aims to: (1) examine which aspects of hypothesised altered reward and punishment sensitivity correspond to constructs measured by existing questionnaires, (2) characterise the relationships between ADHD symptomatology and reward and punishment sensitivity as measured by existing questionnaires and (3) evaluate the consistency between the altered reward and punishment sensitivity as measured by existing questionnaires and experimental task performance.

METHODS AND ANALYSIS

Reporting of the scoping review results will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews and the Joanna Briggs Methodology for Scoping Reviews. Published English-language literature was searched in three electronic databases (PubMed, Web of Science, APA PsycINFO) on 16 November 2023, with no restriction on the year of publication. Two researchers independently screened all identified titles/abstracts before proceeding to full-text review and additional handsearching of relevant studies. A narrative review and conclusions will be presented together with tables summarising the articles reviewed and the results organised by the three aims.

ETHICS AND DISSEMINATION

This study reviews existing publications with ethical approval in place. Therefore, ethical approval is not required. Review results will be disseminated through academic conferences and peer-reviewed manuscripts. Scoping review results will also inform future research to measure and identify altered motivational processes in ADHD.

Measuring Pleasure from Food-Validation of the Food Pleasure Scale by Multiple Techniques and Mixed Methods

The development of scales and questionnaires to assess pleasure perception has gained prominence, particularly for evaluating anhedonia in mental disorders. The Food Pleasure Scale is a comprehensive tool exclusively dedicated to measuring pleasure perception from food and food-related experiences. This study aimed to evaluate the face validity and consistency reliability of the Food Pleasure Scale using a mixed methods approach. Twenty-two participants completed the Food Pleasure Scale questionnaire and participated in in-depth interviews to understand their interpretation of the scale items. The interview data underwent thematic analysis, and the quantitative survey data was compared to the qualitative interview responses. Results indicated a high level of understanding of all items in the Food Pleasure Scale, confirming its face validity and applicability. The mixed methods approach supported the consistency reliability, showing consistency between quantitative measures and participants' explicit and implicit expressions of food pleasure. Furthermore, the study revealed a novel aspect related to food pleasure: the concept of "making an effort". Overall, this study highlights the comprehensibility, validity, and potential of the Food Pleasure Scale in consumer studies. It effectively captures the subjective experience of pleasure derived from food and food-related encounters, making it a valuable tool for further research in this domain.

Polish adaptation of the Dimensional Anhedonia Rating Scale (DARS) - validation in the clinical sample

Background

Anhedonia is the core symptom of depression. Its presence has been linked to worsened prognosis. The Dimensional Anhedonia Rating Scale (DARS) is a scale measuring desire, motivation, effort and consummatory pleasure across different domains. The aim of this paper was to confirm factor structure, assess reliability and validity of the Polish adaptation of the DARS in a clinical sample of patients with mood disorders and healthy controls (HC).

Methods

The study sample included 161 participants aged 18-65 years - 34 HC, 72 patients with bipolar disorder and 55 with major depressive disorder (in depressive episode or remission). Reliability of the Polish adaptation of the DARS was assessed using Cronbach's α and the average inter-item correlation (AIC). Convergent and divergent validity was established by Pearson's correlations between the DARS and the Snaith-Hamilton Pleasure Scale (SHAPS), the Quick Inventory of Depressive Symptomatology- self-report (QIDS-SR), the Hospital Anxiety and Depression Scale (HADS). The structure of the scale was examined by factor analysis.

Results

The factor structure was consistent with the original scale. Strong internal consistency for the DARS total score (Cronbach's α = 0.95) and all subscales (0.86-0.93) was observed. The DARS demonstrated good convergent (moderate to strong correlations with measures of anhedonia and depression) and divergent validity (weak correlations with anxiety level).

Conclusion

The Polish DARS demonstrated excellent internal consistency and very good validity. The scale is a valuable contribution to the psychometrics of anhedonia measures in patients with mood disorders.

Apathy in melancholic depression and abnormal neural activity within the reward-related circuit

Major depressive disorder is a heterogeneous syndrome, of which the most common subtype is melancholic depression (MEL). Previous studies have indicated that anhedonia is frequently a cardinal feature in MEL. As a common syndrome of motivational deficit, anhedonia is closely associated with dysfunction in reward-related networks. However, little is currently known about apathy, another syndrome of motivational deficits, and the underlying neural mechanisms in MEL and non-melancholic depression (NMEL). Herein, the Apathy Evaluation Scale (AES) was used to compare apathy between MEL and NMEL. On the basis of resting-state functional magnetic resonance imaging, functional connectivity strength (FCS) and seed-based functional connectivity (FC) were calculated within reward-related networks and compared among 43 patients with MEL, 30 patients with NMEL, and 35 healthy controls. Patients with MEL had higher AES scores than those with NMEL (t = -2.20, P = 0.03). Relative to NMEL, MEL was associated with greater FCS (t = 4.27, P < 0.001) in the left ventral striatum (VS), and greater FC of the VS with the ventral medial prefrontal cortex (t = 5.03, P < 0.001) and dorsolateral prefrontal cortex (t = 3.18, P = 0.005). Taken together the results indicate that reward-related networks may play diverse pathophysiological roles in MEL and NMEL, thus providing potential directions for future interventions in the treatment of various depression subtypes.

Promoting Recovery from Disasters, Pandemics, and Trauma: A Systematic Review of Brief Psychological Interventions to Reduce Distress in Adults, Children, and Adolescents

A substantial number of survivors of disasters, pandemics, and other severe stressors develop persistent distress that impairs mental health and well-being. However, only a few brief psychological interventions target distress or subclinical symptoms. This systematic review aimed to identify and describe brief psychological interventions to reduce distress or subclinical symptoms in survivors of disasters, pandemics, and other severe stressors. Based on a systematic literature search (MEDLINE, PsycINFO, PSYNDEX, PTSDpubs, and Web of Science), we reviewed published studies and study protocols on self-help, psychosocial support, or brief psychotherapeutic interventions to reduce distress and/or subclinical symptoms following natural hazards and man-made disasters, pandemics, or other traumatic events. We included 27 published studies or study protocols (n = 15 RCTs, n = 3 controlled pre-post studies, and n = 9 uncontrolled pre-post studies) describing 22 interventions. We found evidence for reducing psychological distress and/or subclinical symptoms in 9 out of 15 RCTs, 2 out of 3 controlled pre-post studies, and 9 out of 9 uncontrolled pre-post studies. One RCT provided evidence of increasing well-being. Innovative brief interventions have been developed to reduce distress and/or subclinical symptoms that have an emerging evidence base.

The neural correlation of emotion recognition ability and depressive symptoms-evidence from the HCP database

INTRODUCTION

Negative bias of emotional face is the core feature of depression, but its underlying neurobiological mechanism is still unclear. The neuroimaging findings of negative emotional recognition and depressive symptoms are inconsistent.

METHODS

The neural association between depressive symptoms and negative emotional bias were analyzed by measuring the associations between resting state functional connectivity (FC), brain structures, negative emotional bias, and depressive problems. Then, we performed a mediation analysis to assess the potential overlapping neuroimaging mechanisms.

RESULTS

We found a negative correlation between depressive symptoms and emotional recognition. Secondly, the structure and function of the inferior and lateral orbitofrontal gyrus are related to depressive symptoms and emotional recognition. Thirdly, the thickness of the inferior orbitofrontal cortex and the FC between the inferior orbitofrontal gyrus and fusiform gyrus, precuneate and cingulate gyrus mediated and even predicted the interaction between emotion recognition and depressive symptoms. Finally, in response to a negative stimulus, the activation of the frontal pole and precuneus lobe associated with the inferior orbitofrontal gyrus was higher in participants with depressive symptoms.

CONCLUSION

The core brain regions centered on the inferior orbitofrontal cortex such as middle temporal gyrus, precuneus lobe, frontal pole, insula and cingulate gyrus are the potential neuroimaging basis for the interaction between depressive symptoms and emotional recognition.

Montgomery-Åsberg Depression Rating Scale factors in treatment-resistant depression at onset of treatment: Derivation, replication, and change over time during treatment with esketamine

OBJECTIVE

Derive and confirm factor structure of the Montgomery-Åsberg Depression Rating Scale (MADRS) in patients with treatment-resistant depression (TRD) and evaluate how the factors evident at baseline change over 4 weeks of esketamine treatment.

METHODS

Two similarly-designed, short-term TRANSFORM trials randomized adults to esketamine or matching placebo nasal spray, each with a newly-initiated oral antidepressant, for 4 weeks (TRANSFORM-1: N = 342 patients; TRANSFORM-2: N = 223 patients). The factor structure of MADRS item scores at baseline was determined by exploratory factor analysis in TRANSFORM-2 and corroborated by confirmatory factor analysis in TRANSFORM-1. Change in MADRS factor scores from baseline (day 1) to the end of the 28-day double-blind treatment phase of TRANSFORM-2 was analyzed using a mixed-effects model for repeated measures (MMRM).

RESULTS

Three factors were identified based on analysis of MADRS items: Factor 1 labeled affective and anhedonic symptoms (apparent sadness, reported sadness, lassitude, inability to feel), Factor 2 labeled anxiety and vegetative symptoms (inner tension, reduced sleep, reduced appetite, concentration difficulties), and Factor 3 labeled hopelessness (pessimistic thoughts, suicidal thoughts). The three-factor structure observed in TRANSFORM-2 was verified in TRANSFORM-1. Treatment benefit at 24 h with esketamine versus placebo was observed on all 3 factors and continued throughout the 4-week double-blind treatment period.

CONCLUSIONS

A three-factor structure for MADRS appears to generalize to TRD. All three factors improved over 4 weeks of treatment with esketamine nasal spray.

Patient-reported outcome measures for life engagement in mental health: a systematic review

Background

Life engagement in the context of mental health is a broad term that describes positive health aspects relating to cognition, vitality, motivation and reward, and the ability to feel pleasure—concepts that are meaningful to patients. The aim of this systematic literature review was to identify validated patient-reported outcomes (PROs) that can assess any aspect of life engagement in adults, in the field of general mental health.

Methods

This was a systematic literature review of articles in English from the MEDLINE database (date of search: September 9, 2020). The search strategy had three components: (1) terms to capture PROs; (2) terms to capture mental health; and (3) terms to capture aspects of life engagement. Articles were eligible if they included a PRO that: (1) is named; (2) can be used across mental health disorders; (3) is used to assess any aspect of life engagement; and (4) has undergone psychometric validation and/or qualitative content validation. A list of PROs was extracted.

Results

A total of 1585 records were screened and 233 articles were eligible for inclusion. Within these 233 articles, 49 distinct PROs were identified, two of which specifically captured their authors’ interpretation of life engagement: the Engaged Living Scale (ELS) and the Life Engagement Test (LET). However, while the ELS and LET covered motivation and reward, life fulfillment, and value-based living, neither scale captured the cognitive or vitality aspects of life engagement. The remaining identified PROs generally captured single aspects of life engagement, most commonly motivation/reward/energy–apathy, pleasure–anhedonia, and mental/psychological well-being.

Conclusion

Numerous PROs are available that may capture aspects of life engagement. However, a need remains for a new PRO that can be used in clinical trials to provide a more comprehensive description of the improvements in life engagement that patients with mental health disorders may experience with successful treatment.

Sucrose Preference Test as a Measure of Anhedonic Behavior in a Chronic Unpredictable Mild Stress Model of Depression: Outstanding Issues

Despite numerous studies on the neurobiology of depression, the etiological and pathophysiological mechanisms of this disorder remain poorly understood. A large number of animal models and tests to evaluate depressive-like behavior have been developed. Chronic unpredictable mild stress (CUMS) is the most common and frequently used model of depression, and the sucrose preference test (SPT) is one of the most common tests for assessing anhedonia. However, not all laboratories can reproduce the main effects of CUMS, especially when this refers to a decrease in sucrose preference. It is also unknown how the state of anhedonia, assessed by the SPT, relates to the state of anhedonia in patients with depression. We analyzed the literature available in the PubMed database using keywords relevant to the topic of this narrative review. We hypothesize that the poor reproducibility of the CUMS model may be due to differences in sucrose consumption, which may be influenced by such factors as differences in sucrose preference concentration threshold, water and food deprivation, and differences in animals’ susceptibility to stress. We also believe that comparisons between animal and human states of anhedonia should be made with caution because there are many inconsistencies between the two, including in assessment methods. We also tried to offer some recommendations that should improve the reproducibility of the CUMS model and provide a framework for future research.

Clinical and Preclinical Assessments of Anhedonia in Psychiatric Disorders

Anhedonia is a prevalent symptom across many psychiatric disorders. The contemporary scope of anhedonia across various models includes interest, reward anticipation, motivation, effort expenditure, reward valuation, expectation, pleasure, satiation, and learning. In order to further elucidate the impact of anhedonia on treatment outcomes, quality of life, as well as brain function, validated tools to probe the various facets of anhedonia are necessary. This chapter evaluates assessment tools for anhedonia in clinical populations and in animals. Subjective clinical scales have been in use for decades, and as the construct of anhedonia evolved, contemporary scales were developed to integrate these new concepts. Clinical scales are useful for understanding the subjective experience of anhedonia but do not account for objective aspects of anhedonia, including implicit learning. Behavioral tasks that probe responses to rewarding stimuli have been useful to fill this gap and to delineate the specific brain processes underlying facets of anhedonia. Although there have been translational challenges in the assessments of anhedonia and reward deficits from preclinical to clinical (and vice versa), the multifaceted clinical scales and reward tasks provide valuable insights into the conceptualization of anhedonia and its neural basis across psychiatric disorders.

Vicarious ratings of self vs. other-directed social touch in women with and recovered from Anorexia Nervosa

Anorexia Nervosa (AN) is an eating pathology characterized by restricted eating, body image distortions and impaired socio-cognitive abilities. Altered responses to affective touch—a pleasant interoceptive stimulus hypothesised to involve activation of the C-Tactile (CT) system, may contribute to the aetiology and maintenance of this disorder. Here, we investigated whether third-party social touch vicarious ratings of different body sites at CT-optimal vs. non-CT optimal velocities differed in women with and recovered from AN (RAN) and healthy controls (HCs). Thirty-five HCs, 27 AN and 29 RAN provided pleasantness ratings for two different tasks designed to probe expectations of how touch is perceived by self (self-directed touch) vs. others (other-directed touch). Findings revealed that both clinical groups, compared to HCs, did not differ in their pleasantness ratings to touch for another but when evaluating touch for self, both clinical groups rated CT-optimal touch as less pleasant than HCs. These findings suggest that AN and RAN women demonstrate an atypical vicarious pleasantness response to affective touch involving self, but not others. Novel therapeutic approaches that help anorexics to better interpret or improve tolerance of affective tactile experiences involving the self may be an important addition to current standard treatments.

Is Stress Taking the Pleasure out of Food?—A Characterization of the Food Pleasure Profiles, Appetite, and Eating Behaviors of People with Chronic Stress

Psychological stressors frequently occur in modern society, and are associated with general anhedonic traits (inability to experience pleasure) and altered eating behavior. As eating behavior is largely motivated by a desire for pleasure, the Food Pleasure Scale (FPS) was introduced as a new research tool for investigating aspects of pleasure from food-related experiences. Thereby, insights on whether some aspects of pleasure are more affected by stress than others can be investigated, and can help explain why changes in eating behavior are seen when under the influence of stress. A consumer survey including n = 190 Danish consumers all with moderate or high levels of perceived stress was conducted to explore the perception of pleasure from food, general appetite, meal patterns, as well as specific food preferences. The study showed that the majority found pleasure in the sensory modalities of food, as well as in the ‘comforting’ aspects of food pleasure. Furthermore, the moderately stressed respondents had fewer main meals and more post-dinner snacks and night meals, as compared to before falling ill, whereas the highly stressed group showed signs of anhedonic traits and losing appetite altogether. The present study contributes to our understanding of how a common condition, such as chronic stress, can affect individual, as well as public, health.

Link between structural connectivity of the medial forebrain bundle, functional connectivity of the ventral tegmental area, and anhedonia in unipolar depression

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Tract volume and number of tracts are reduced in the left slMFB.

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Those microstructural alterations are related to depression severity and anhedonia.

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There is increased VTA-PFC functional connectivity in depression.

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Those increases are more pronounced in patients with severe anhedonia.

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Our results extend pathophysiological models of anhedonia in depression.

The ventral tegmental area (VTA), nucleus accumbens (NAcc), and prefrontal cortex (PFC) are essential for experiencing pleasure and initiating motivated behaviour. The VTA, NAcc, and PFC are connected through the medial forebrain bundle (MFB). In humans, two branches have been described: an infero-medial branch (imMFB) and a supero-lateral branch (slMFB). This study aimed to explore the associations between structural connectivity of the MFB, functional connectivity (FC) of the VTA, anhedonia, and depression severity in patients with depression. Fifty-six patients with unipolar depression and 22 healthy controls matched for age, sex, and handedness were recruited at the University Hospital of Psychiatry and Psychotherapy in Bern, Switzerland. Diffusion-weighted imaging and resting-state functional magnetic resonance imaging scans were acquired. Using manual tractography, the imMFB and slMFB were reconstructed bilaterally for each participant. Seed-based resting-state FC was computed from the VTA to the PFC. Hedonic tone was assessed using the Fawcett-Clark Pleasure Scale. We identified reduced tract volume and reduced number of tracts in the left slMFB. There was an increase in FC between the VTA and right medial PFC in patients with depression. Depression severity was associated with reduced tract volume and fewer tracts in the left slMFB. Reduced hedonic tone was associated with reduced tract volume. Conversely, reduced hedonic tone was associated with increased FC between the VTA and the PFC. In conclusion, our results suggest reduced structural connectivity of the slMFB in patients with depression. Increases in FC between the VTA and PFC may be associated with anhedonia or compensatory hyperactivity.

Evaluating the item-level factor structure of anhedonia

BACKGROUND

Anhedonia has long been theorized to be a multidimensional construct, focusing on domains of reward stimuli and temporal relationship to reward. However, little empirical work has directly examined whether there is support for this assertion.

METHODS

The study used data from young adults from four independent samples (n = 2098). Participants completed multiple measures of anhedonia.

RESULTS

We used rigorous conducted exploratory and confirmatory factor analyses on items from six commonly used anhedonia measures to examine dimensions underlying anhedonia. Results suggested a four-factor solution with factors reflecting social reward, social disinterest, status/achievement, and physical/natural reward. The identified factors reflected broad content domains of pleasure, but not specific reward processes. The four factors were modestly associated with one another, suggesting a weak common underlying anhedonia trait that manifests across multiple dimensions. Factor scores were associated with personality measures, reward-related indices, and depression symptoms, supporting the validity of the factors.

LIMITATIONS

Participants were all young adults and we assessed anhedonia only at the level of self-report.

CONCLUSION

Anhedonia is a multidimensional construct. However, the dimensions of anhedonia only distinguish domains of, but not temporal processes of anhedonia. Future work should continue to refine the structures underlying the construct of anhedonia through iterative theory- and data-driven research and examine associations between anhedonia and clinical outcomes.

A cross-species assay demonstrates that reward responsiveness is enduringly impacted by adverse, unpredictable early-life experiences

Exposure to early-life adversity (ELA) is associated with several neuropsychiatric conditions, including major depressive disorder, yet causality is difficult to establish in humans. Recent work in rodents has implicated impaired reward circuit signaling in anhedonic-like behavior after ELA exposure. Anhedonia, the lack of reactivity to previously rewarding stimuli, is a transdiagnostic construct common to mental illnesses associated with ELA. Here, we employed an assay of reward responsiveness validated across species, the Probabilistic Reward Task (PRT). In the PRT, healthy participants reliably develop a response bias toward the more richly rewarded stimulus, whereas participants with anhedonia exhibit a blunted response bias that correlates with current and future anhedonia. In a well-established model of ELA that generates a stressful, chaotic, and unpredictable early-life environment, ELA led to blunted response biases in the PRT in two separate cohorts, recapitulating findings in humans with anhedonia. The same ELA rats had blunted sucrose preference, further supporting their anhedonic-like phenotypes. Probing the aspects of ELA that might provoke these deficits, we quantified the unpredictability of dam/pup interactions using entropy measures and found that the unpredictability of maternal care was significantly higher in the ELA groups in which PRT and sucrose preference reward deficits were present later in life. Taken together, these data position the PRT, established in clinical patient populations, as a potent instrument to assess the impact of ELA on the reward circuit across species. These findings also implicate the unpredictability of maternal signals during early life as an important driver of reward sensitivity deficits.

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.

Acute tryptophan depletion alters affective touch perception

RATIONALE

Affiliative tactile interactions help regulate physiological arousal and confer resilience to acute and chronic stress. C-tactile afferents (CTs) are a population of unmyelinated, low threshold mechanosensitive cutaneous nerve fibres which respond optimally to a low force stimulus, moving at between 1 and 10 cm/s. As CT firing frequencies correlate positively with subjective ratings of touch pleasantness, they are hypothesised to form the first stage of encoding affiliative tactile interactions. Serotonin is a key modulator of social responses with known effects on bonding.

OBJECTIVES

The aim of the present study was to determine the effect of acutely lowering central serotonin levels on perceptions of CT-targeted affective touch.

METHODS

In a double blind, placebo-controlled design, the effect of acute tryptophan depletion (ATD) on 25 female participants' ratings of directly and vicariously experienced touch was investigated. Psychophysical techniques were used to deliver dynamic tactile stimuli; some velocities were targeted to optimally activate CTs (1-10 cm/s), whereas other, faster and slower strokes fell outside the CT optimal range. Discriminative tactile function, cold pain threshold and tolerance were also measured.

RESULTS

ATD significantly increased pleasantness ratings of both directly and vicariously experienced affective touch, increasing discrimination of the specific hedonic value of CT targeted velocities. While ATD had no effect on either tactile or cold pain thresholds, there was a trend for reduced tolerance to cold pain.

CONCLUSIONS

These findings are consistent with previous reports that depletion of central serotonin levels modulates neural and behavioural responsiveness to appetitive sensory signals.

Effectiveness of a Videoconferencing-Delivered Psychological Intervention for Mental Health Problems during COVID-19: A Proof-of-Concept Randomized Clinical Trial

INTRODUCTION

Anxiety and depression have increased markedly during the COVID-19 pandemic. There is a lack of evidence-based strategies to address these mental health needs during the pandemic.

OBJECTIVE

We aim to conduct a proof-of-concept trial of the efficacy of a brief group-based psychological intervention delivered via videoconferencing for adults in Australia distressed by the pandemic.

METHODS

In this single-blind, parallel, randomised controlled trial, adults who screened positive for COVID-related psychological distress across Australia were randomly allocated to either a 6-session group-based program based on behavioural principles (n = 120) or enhanced usual care (EUC, n = 120). Primary outcome was total score on the Hospital Anxiety and Depression (HADS) anxiety and depression subscales assessed at baseline, 1 week posttreatment, 2 months (primary outcome time point), and 6 months after treatment, as well as secondary outcome measures of worry, sleep impairment, anhedonia, mood, and COVID-19-related stress.

RESULTS

Between May 20, 2020, and October 20, 2020, 240 patients were enrolled into the trial. Relative to EUC, at 2 months participants receiving intervention showed greater reduction on anxiety (mean difference, 1.4 [95% CI, 0.3 to 2.6], p = 0.01; effect size, 0.4 [95% CI, 0.1 to 0.7]) and depression (mean difference, 1.6 [95% CI, 0.4 to 2.8], p = 0.009; effect size, 0.4 [95% CI, 0.2 to 0.7]) scales. These effects were maintained at 6 months. There were also greater reductions of worry, anhedonia, COVID-19-related fears, and contamination fears.

CONCLUSIONS

This trial provides initial evidence that brief group-based behavioural intervention delivered via videoconferencing results in moderate reductions in common psychological problems arising during the COVID-19 pandemic. This program may offer a viable and scalable means to mitigate the rising mental health problems during the pandemic.

Toward a Quantification of Anhedonia: Unified Matching Law and Signal Detection for Clinical Assessment and Drug Development

Anhedonia, the loss of pleasure from previously rewarding activities, is a core symptom of several neuropsychiatric conditions, including major depressive disorder (MDD). Despite its transdiagnostic relevance, no effective therapeutics exist to treat anhedonia. This is due, in part, to inconsistent assays across clinical populations and laboratory animals, which hamper treatment development. To bridge this gap, recent work has capitalized on two long-standing research domains dedicated to quantifying responsivity to antecedents and consequences across species: the generalized matching law and signal detection theory. This review traces the integration of these quantitative frameworks, which yielded two empirically derived metrics: response bias (log b) and task discriminability (log d). These metrics serve as primary dependent variables in the Probabilistic Reward Task (PRT). In this computerized task, subjects make visual discriminations and probabilistic contingencies are arranged such that correct responses to one alternative are rewarded more often (rich) than correct responses to the other (lean). Under these conditions, healthy participants consistently develop a response bias in favor of the rich alternative, whereas participants with MDD exhibit blunted biases, which correlate with current and predict future anhedonia. Given the correspondence between anhedonic phenotypes and response bias, the PRT has been reverse-translated for rodents and nonhuman primates. Orderly log b and log d values have been observed across diverse clinical populations and laboratory animals. In addition, pharmacological challenges have produced similar outcomes across species. Taken together, this quantitative framework offers a highly translational approach to assaying reward responsiveness to accelerate treatment development for neuropsychiatric disorders involving anhedonia.

Neural signatures of saliency-mapping in anhedonia: A narrative review

Anhedonia is the loss of pleasure or motivation to engage in previously enjoyable activities, and is a transdiagnostic symptom associated with significant clinical impairment. Anhedonia is implicated in several different psychiatric disorders, presenting a promising opportunity for transdiagnostic treatment. Thus, developing targeted treatments for anhedonia is of critical importance for population mental health. An important first step in doing so is establishing a thorough understanding of the neural correlates of anhedonia. The Triple Network Model of Psychopathology provides a frame for how brain activity may go awry in anhedonia, specifically in the context of Salience Network (SN) function (i.e., saliency-mapping). We present a narrative review examining saliency-mapping as it relates to anhedonia severity in depressed and transdiagnostic adult samples. Results revealed increased anhedonia to be associated with hyperactivity of the SN at rest and in the context of negative stimuli, as well as a global lack of SN engagement in the context of positive stimuli. Potential treatments for anhedonia are placed within this model, and future directions for research are discussed.

A Conceptual Framework for Multi-Dimensional Measurements of Food Related Pleasure-The Food Pleasure Scale

In modern times, the majority of food intake is believed to be driven by hedonic processes, rather than homeostatic ones. Various factors have been found to influence the hedonic eating experience and thereby influence eating behaviour, and each factor can be regarded a piece that contributes to parts of the total picture of the hedonic response to food. As a result, the literature on the hedonic response to food-related experiences is comprehensive, but at the same time rather fragmented; and importantly, it is not clear how individuals/segments differ in key drivers of their hedonic experience and the extent to which food pleasure is perceived. In this paper, we present a conceptual framework for the development of a scale (self-report questionnaire) to measure the qualitative and quantitative aspects of food-related pleasure, the Food Pleasure Scale. We introduce the concept of (an)hedonia and scales developed in the past for its measurement, identify the spectrum of characteristics influencing food-related pleasure and explain the relevance of developing such a scale. Based on this theoretical framework, a strategy for the development of the Food Pleasure Scale is proposed.

Anhedonia as a central factor in depression: Neural mechanisms revealed from preclinical to clinical evidence

Anhedonia is one of the core symptoms of major depressive disorder (MDD), which is often inadequately treated by traditional antidepressants. The modern framework of anhedonia extends the definition from impaired consummatory pleasure or interest in rewards to a broad spectrum of deficits that impact functions such as reward anticipation, approach motivation, effort expenditure, reward valuation, expectation, and reward-cue association learning. Substantial preclinical and clinical research has explored the neural basis of reward deficits in the context of depression, and has implicated mesocorticolimbic reward circuitry comprising the nucleus accumbens, ventral pallidum, ventral tegmental area, amygdala, hippocampus, anterior cingulate, insula, orbitofrontal cortex, and other prefrontal cortex regions. Dopamine modulates several reward facets including anticipation, motivation, effort, and learning. As well, serotonin, norepinephrine, opioids, glutamate, Gamma aminobutyric acid (GABA), and acetylcholine are also involved in anhedonia, and medications targeting these systems may also potentially normalize reward processing in depression. Unfortunately, whereas reward anticipation and reward outcome are extensively explored by both preclinical and clinical studies, translational gaps remain in reward motivation, effort, valuation, and learning, where clinical neuroimaging studies are in the early stages. This review aims to synthesize the neurobiological mechanisms underlying anhedonia in MDD uncovered by preclinical and clinical research. The translational difficulties in studying the neural basis of reward are also discussed.

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.

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.

Genetic and Depressive Traits Moderate the Reward-Enhancing Effects of Acute Nicotine in Young Light Smokers

INTRODUCTION

Rates of light smoking have increased in recent years and are associated with adverse health outcomes. Reducing light smoking is a challenge because it is unclear why some but not others, progress to heavier smoking. Nicotine has profound effects on brain reward systems and individual differences in nicotine's reward-enhancing effects may drive variability in smoking trajectories. Therefore, we examined whether a genetic risk factor and personality traits known to moderate reward processing, also moderate the reward-enhancing effects of nicotine.

METHODS

Light smokers (n = 116) performed a Probabilistic Reward Task to assess reward responsiveness after receiving nicotine or placebo (order counterbalanced). Individuals were classified as nicotine dependence 'risk' allele carriers (rs16969968 A-allele carriers) or non-carriers (non-A-allele carriers), and self-reported negative affective traits were also measured.

RESULTS

Across the sample, reward responsiveness was greater following nicotine compared to placebo (p = 0.045). For Caucasian A-allele carriers but not non-A-allele carriers, nicotine enhanced reward responsiveness compared to placebo for those who received placebo first (p = 0.010). Furthermore, for A-allele carriers but not non-A-allele carriers who received nicotine first, the enhanced reward responsiveness in the nicotine condition carried over to the placebo condition (p < 0.001). Depressive traits also moderated the reward-enhancing effects of nicotine (p = 0.010) and were associated with blunted reward responsiveness following placebo but enhanced reward responsiveness following nicotine.

CONCLUSION

These findings suggest that individual differences in a genetic risk factor and depressive traits alter nicotine's effect on reward responsiveness in light smokers and may be important factors underpinning variability in smoking trajectories in this growing population.

IMPLICATIONS

Individuals carrying genetic risk factors associated with nicotine dependence(rs16969968 A-allele carriers) and those with higher levels of depressive personality traits, showmore pronounced increases in reward learning following acute nicotine exposure. These findingssuggest that genetic and personality factors may drive individual differences in smoking trajectoriesin young light smokers by altering the degree to which nicotine enhances reward processing.

CLINICAL TRIAL REGISTRATION

NCT02129387 (pre-registered hypothesis: www.clinicaltrials.gov).

Assessing the relationship between the human learned helplessness depression model and anhedonia

The learned helplessness (LH) model is one of the most commonly used acute stress models to explain depression and it has shown good face and predictive validity. However, despite being able to induce depressed-like behaviors and corresponding psychophysiological changes, there is little evidence showing that the LH paradigm can produce anhedonia, a core symptom seen in all forms of depression in humans. So far a couple of studies showed that rodents bred for helplessness develop anhedonic-like behaviors in response to stress; yet, to the best of our knowledge, no similar human research has tried to investigate the direct relationship between the LH model and anhedonia. In the present study, we use a modified version of the original LH task to experimentally and temporarily induce learned helplessness in college students and then examine if the human LH paradigm induces anhedonia. We aim to 1: address the ill-defined connection between the LH model and anhedonia, and 2: directly assess helplessness in humans as opposed to the majority of non-human animal subjects used in the helplessness literature. We believe that our study will fill an important gap in the learned helplessness model literature, and will advance our understanding of the relationship between depression and perceived control, as well as place limitations to what can and cannot be inferred from non-human animal data in this topic.

The relations between pleasurable emotions and depression: Exploring the potential significance of contentment

BACKGROUND

Previous research has found that the diminished ability to experience pleasure is a common feature of depression, but has not examined whether depression is associated equally strongly with the different types of pleasurable emotions. Contentment, which has been found to be especially strongly associated with life satisfaction and is associated with a sense of completeness or completion, was expected to be especially relevant to depression.

METHODS

In two studies, participants (N = 70, and N = 109), who were receiving outpatient treatment, completed self-report measures of depression, contentment, tranquility, and cheerfulness. Worry and suicidality were also measured, in Studies 1 and 2, respectively.

RESULTS

As hypothesized: (a) contentment was associated as strongly with depression as was cheerfulness; (b) contentment was more strongly associated with depression than was tranquility; (c) contentment was more strongly associated with depression than it was with worry; and (d) contentment was associated with suicidality even after taking into account depression severity, cheerfulness and tranquility.

LIMITATIONS

The present research relied on self-report. Because both studies employed cross-sectional designs, conclusions regarding causality cannot be drawn.

CONCLUSIONS

Contentment is associated with depression, even after taking into account other pleasurable emotions. The present findings raise the possibility that attending to different types of pleasurable emotions, such as contentment, may be important for understanding the different potential pathways to depression, and may be capable of predicting differential responses to alternative treatments for depression.

Brief videoconferencing psychological intervention for reducing COVID-19 related distress: study protocol for a randomized controlled trial

Background

Globally COVID-19 has had a profound impact on the psychological wellbeing of millions of people, and there is an urgent imperative to address elevated levels of distress during the COVID-19 pandemic. The World Health Organization (WHO) has developed Problem Management Plus (PM+), a low intensity psychological intervention for adults experiencing psychological distress. This paper outlines the study protocol for a trial that tests the effectiveness of an adapted version of PM+ to reduce distress associated with COVID-19.

Methods

A single-blind, parallel, randomized controlled trial will be carried out for distressed people across Australia. via video conferencing on a small group basis. Following informed consent, adults that screen positive for levels of psychological distress (General Health Questionnaire-12 (GHQ-12 score ≥ 3) and have access to videoconferencing platform will be randomised to an adapted version of gPM+ (n = 120) or enhanced treatment as usual (ETAU) (n = 120). The primary outcome will be reduction in psychological distress including anxiety and depression at 2-months post treatment. Secondary outcomes include worry, sleep problems, anhedonia, social support, and stress in relation to COVID-19.

Discussion

The trial aims assess whether an adapted version of videoconferencing PM+ that is specifically designed to target COVI-19 related distress will result in reduced distress relative to enhanced usual care.

Trial registration

This trial was prospectively registered on the ANZCTR on 14/4/20 (ACTRN12620000468921).

Time-varying effects of 'optimized smoking treatment' on craving, negative affect and anhedonia

AIMS

To identify when smoking cessation treatments affect craving, negative affect and anhedonia, and how these symptoms relate to abstinence, to help evaluate the effects of particular intervention components in multi-component treatments and accelerate treatment refinement.

DESIGN

Secondary analysis of data from a two-arm randomized controlled trial.

SETTING

Seven primary care clinics in Wisconsin, United States.

PARTICIPANTS

Adult primary care patients who smoked daily (n = 574).

INTERVENTION AND COMPARATOR

Intervention was abstinence-optimized treatment (A-OT, n = 276) comprising 3 weeks of nicotine mini-lozenges pre-target quit day (TQD), 26 weeks of combination nicotine patch and mini-lozenges post-TQD and extensive psychosocial support. The comparator was recommended usual care (RUC, n = 298), comprising brief counseling and 8 weeks of nicotine patch post-TQD.

MEASUREMENTS

Time-varying effect models examined dynamic effects of A-OT (versus RUC) on the primary outcomes of nightly cigarette craving, negative affect and anhedonia from 1 week pre- to 2 weeks post-TQD. Exploratory models examined within-person relations between nicotine medication use and same-day symptom ratings. Secondary logistic regression analyses examined associations between post-TQD craving, negative affect and anhedonia and 1-month post-TQD abstinence.

FINDINGS

A-OT significantly suppressed pre- and post-TQD craving (β = -0.27 to -0.46 across days) and post-TQD anhedonia (β = -0.24 to -0.38 across days), relative to RUC. Within individuals, using patches was associated with lower negative affect in RUC (β = -0.42 to -0.52), but not in A-OT. Using more mini-lozenges was associated with greater craving (β = 0.04-0.07) and negative affect (β = 0.03-0.05) early, and with lower anhedonia (β = -0.06 to -0.12) later. Greater post-TQD craving (OR = 0.68) and anhedonia (OR = 0.85) predicted lower odds of abstinence 1 month post-TQD.

CONCLUSION

Time-varying effect models showed that a multi-component treatment intervention for smoking cessation suppressed significant withdrawal symptoms more effectively than recommended usual care among daily adult smokers motivated to quit. The intervention reduced craving pre- and post-target quit day (TQD) and anhedonia post-TQD.

Factor Structure and Measurement Invariance of the Chinese version of the Snaith-Hamilton Pleasure Scale (SHAPS) in Non-clinical and Clinical populations

BACKGROUND

Anhedonia, a key symptom of depression and schizophrenia, has emerged as a potential endophenotype. The aim of this study was to evaluate the psychometric properties of a Chinese version of the Snaith-Hamilton Pleasure Scale(SHAPS), a self-report anhedonia scale, in a non-clinical sample and clinical sample inclusive of major depressive disorder (MDD), schizophrenia, or a personality disorder.

METHODS

A total of 4,722 undergraduate students and 352 clinical patients participated in this study. Internal consistency was assessed by calculating Cronbach's α and mean inter-item correlation (MIC) values. Test-retest reliability and convergent validity were assessed with Pearson r coefficients. The best fitting of six potential factor-structure models was determined by confirmatory factor analysis (CFA). Measurement invariance across genders and samples was determined by multi-group CFA.

RESULTS

Internal consistency of the Chinese version of the SHAPS was acceptable in non-clinical (Cronbach's α = 0.90) and clinical (Cronbach's α = 0.91) samples. Four-week interval test-retest reliability was 0.60. Moreover, the Spanish four-factor structure had the best fit indexes in both samples. Scalar invariance was established across genders as well as across non-clinical sample and clinical sample. SHAPS was significantly related with the Temporal Experience of Pleasure Scale (TEPS) and Beck Depression Inventory (BDI).

LIMITATIONS

There was a restricted scope of convergent validity and the size of clinical sample is relatively small, psychometric properties in elderly sample is also required.

CONCLUSION

The Chinese version of the SHAPS is a reliable, effective, simple and convenient tool for assessing and screening for anhedonia.

Severe anhedonia among adolescents with bipolar disorder is common and associated with increased psychiatric symptom burden

BACKGROUND

Anhedonia, a deficit in the ability to experience pleasure, is a cardinal symptom of major depressive episodes. In contrast to adolescent major depressive disorder, there is limited research examining anhedonia in the context of depression among adolescents with bipolar disorder (BD). We therefore examined clinical characteristics of anhedonia in a large sample of adolescents with BD.

METHODS

Participants were 197 adolescents, aged 13-20 years old, with BD type I, II or not otherwise specified. Diagnoses were determined using a semi-structured interview. Anhedonia severity was rated from one to six on the Depression Rating Scale (DRS). Adolescents were divided into "severe" and "non-severe" anhedonia groups based on the DRS item scoring. The association of anhedonia with clinical and demographic variables was evaluated in univariate analyses followed by logistic regression analyses for variables with p ≤ 0.1.

RESULTS

Threshold anhedonia was evident among 90.9% during their most severe depressive episode. Significant factors associated with severe most severe lifetime anhedonia ("lifetime anhedonia") included: female sex, lifetime history of self-injurious behavior, physical abuse, affective lability, higher lifetime depression severity, comorbid anxiety disorders, family history of ADHD, and second-generation antipsychotic use. In regression analyses, severe lifetime anhedonia was independently associated with female sex, comorbid anxiety disorders, most severe lifetime mania severity, and lifetime second-generation antipsychotic use.

CONCLUSION

The vast majority of adolescents with BD experience anhedonia. More severe anhedonia is associated with indicators of greater illness severity. Future research is warranted to evaluate the neurobiological underpinnings of anhedonia among adolescents with BD.

Psychometric properties the of Brazilian Portuguese version of Snaith-Hamilton Pleasure Scale (SHAPS)

INTRODUCTION

Anhedonia is defined as the reduced ability to feel pleasure and is a core symptom of various psychiatric disorders such as depression and schizophrenia. The Snaith-Hamilton Pleasure Scale (SHAPS) was developed to assess the presence of anhedonia. The objective of this study was to assess the psychometric properties of the Brazilian Portuguese version of the SHAPS.

METHODS

In this study, the SHAPS (14 items) was translated into Brazilian Portuguese and validated using data obtained from 228 subjects within a clinical sample. Psychometric properties were assessed using item response theory (logistic models) and classical test theory (Cronbach's alpha). We checked for external validity using a non-parametric correlation with an independent scale: Hospital Anxiety and Depression Scale - Depression subscale (HAD-D).

RESULTS

The SHAPS presented good internal consistency, with a Cronbach's α coefficient of 0.759 and adequacy to an IRT 1 parameter logistic (Rasch) model. The SHAPS presented significant correlation with the external measure HAD-D, with Spearman's ρ = 0.249 (S = 1368914; p < 0.001).

CONCLUSION

These results suggest that the Brazilian Portuguese version of the SHAPS is a reliable and valid instrument to assess hedonic tone.

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.

Toward Precision Medicine for Smoking Cessation: Developing a Neuroimaging-Based Classification Algorithm to Identify Smokers at Higher Risk for Relapse

INTRODUCTION

By improving our understanding of the neurobiological mechanisms underlying addiction, neuroimaging research is helping to identify new targets for personalized treatment interventions. When trying to quit, smokers with larger electrophysiological responses to cigarette-related, compared with pleasant, stimuli ("C > P") are more likely to relapse than smokers with the opposite brain reactivity profile ("P > C").

AIM AND METHOD

The goal was to (1) build a classification algorithm to identify smokers characterized by P > C or C > P neuroaffective profiles and (2) validate the algorithm's classification outcomes in an independent data set where we assessed both smokers' electrophysiological responses at baseline and smoking abstinence during a quit attempt. We built the classification algorithm applying discriminant function analysis on the event-related potentials evoked by emotional images in 180 smokers.

RESULTS

The predictive validity of the classifier showed promise in an independent data set that included new data from 177 smokers interested in quitting; the algorithm classified 111 smokers as P > C and 66 as C > P. The overall abstinence rate was low; 15 individuals (8.5% of the sample) achieved CO-verified 12-month abstinence. Although individuals classified as P > C were nearly 2.5 times more likely to be abstinent than smokers classified as C > P (12 vs. 3, or 11% vs. 4.5%), this result was nonsignificant, preliminary, and in need of confirmation in larger trials.

CONCLUSION

These results suggest that psychophysiological techniques have the potential to advance our knowledge of the neurobiological underpinnings of nicotine addiction and improve clinical applications. However, larger sample sizes are necessary to reliably assess the predictive ability of our algorithm.

IMPLICATIONS

We assessed the clinical relevance of a neuroimaging-based classification algorithm on an independent sample of smokers enrolled in a smoking cessation trial and found those with the tendency to attribute more relevance to rewards than cues were nearly 2.5 times more likely to be abstinent than smokers with the opposite brain reactivity profile (11% vs. 4.5%). Although this result was not statistically significant, it suggests our neuroimaging-based classification algorithm can potentially contribute to the development of new precision medicine interventions aimed at treating substance use disorders. Regardless, these findings are still preliminary and in need of confirmation in larger trials.

The bipolar disorders: A case for their categorically distinct status based on symptom profiles

BACKGROUND

It is unclear whether the bipolar disorders (i.e. BP-I/BP-II) differ dimensionally or categorically. This study sought to clarify this issue.

METHODS

We recruited 165 patients, of which 69 and 96 had clinician-assigned diagnoses of BP-I and BP-II respectively. Their psychiatrists completed a data sheet seeking information on clinical variables about each patient, while the patients completed a different data sheet and scored a questionnaire assessing the prevalence and severity of 96 candidate manic/hypomanic symptoms.

RESULTS

We conducted a series of analyses examining a set (and two sub-sets) of fifteen symptoms that were significantly more likely to be reported by the clinically diagnosed BP-I patients. Latent class analyses favoured two-class solutions, while mixture analyses demonstrated bimodality, thus arguing for a BP-I/BP-II categorical distinction. Statistically defined BP-I class members were more likely when manic to have experienced psychotic features and over-valued ideas. They were also more likely to have been hospitalised, and to have been younger when they received their bipolar diagnosis and first experienced a depressive or manic episode.

LIMITATIONS

The lack of agreement between some patients and managing clinicians in judging the presence of psychotic features could have compromised some analyses. It is also unclear whether some symptoms (e.g. grandiosity, noting mystical events) were capturing formal psychotic features or not.

CONCLUSIONS

Findings replicate our earlier study in providing evidence to support the modelling of BP-I and BP-II as categorically discrete conditions. This should advance research into aetiological factors and determining optimal (presumably differing) treatments for the two conditions.

Chronic Stress Shifts Effort-Related Choice Behavior in a Y-Maze Barrier Task in Mice

Mood disorders, including major depressive disorder, can be precipitated by chronic stress. The Y-maze barrier task is an effort-related choice test that measures motivation to expend effort and obtain reward. In mice, chronic stress exposure significantly impacts motivation to work for a higher value reward when a lesser value reward is freely available compared to unstressed mice. Here we describe the chronic corticosterone administration paradigm, which produces a shift in effortful responding in the Y-maze barrier task. In the Y-maze task, one arm contains 4 food pellets, while the other arm contains only 2 pellets. After mice learn to select the high reward arm, barriers with progressively increasing height are then introduced into the high reward arm over multiple test sessions. Unfortunately, most chronic stress paradigms (including corticosterone and social defeat) were developed in male mice and are less effective in female mice. Therefore, we also discuss chronic non-discriminatory social defeat stress (CNSDS), a stress paradigm we developed that is effective in both male and female mice. Repeating results with multiple distinct chronic stressors in male and female mice combined with increased usage of translationally relevant behavior tasks will help to advance the understanding of how chronic stress can precipitate mood disorders.