Anhedonia in schizophrenia and major depression: state or trait?

Increased BOLD signal in the fusiform gyrus during implicit emotion processing in anorexia nervosa

Background

The behavioural literature in anorexia nervosa (AN) has suggested impairments in psychosocial functioning and studies using facial expression processing tasks (FEPT) have reported poorer recognition and slower identification of emotions.

Methods

Functional magnetic resonance imaging (fMRI) was used alongside a FEPT, depicting neutral, mildly happy and happy faces, to examine the neural correlates of implicit emotion processing in AN. Participants were instructed to specify the gender of the faces. Levels of depression, anxiety, obsessive–compulsive symptoms and eating disorder behaviour were obtained and principal component analysis (PCA) was performed to acquire uncorrelated variables.

Results

fMRI analysis revealed a greater blood-oxygenation level dependent (BOLD) response in AN in the right fusiform gyrus to all facial expressions. This response showed a linear increase with the happiness of the facial expression and was found to be stronger in those not taking medication. PCA analysis revealed a single component indicating a greater level of general clinical symptoms.

Conclusion

Neuroimaging findings would suggest that alterations in implicit emotion processing in AN occur during early perceptual processing of social signals and illustrate greater engagement on the FEPT. The lack of separate components using PCA suggests that the questionnaires used might not be suited as predictive measures.

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Greater BOLD response in AN in the right fusiform gyrus to all facial expressions.

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The BOLD response showed a linear increase with the happiness of the expression

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The BOLD response was stronger in those not taking psychotropic medication

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These alterations occur during early perceptual processing of social signals

Anhedonia revisited: is there a role for dopamine-targeting drugs for depression?

It is 16 years since we reviewed anhedonia in depression. Since then, there have been important developments in the study of anhedonia, mainly using the new techniques that neuroimaging made available, which provide very interesting new insights. It is becoming increasingly apparent that anhedonia, with psychomotor retardation, defines a dimension in depressive disorder that seems to be distinct from a dimension encompassing mood plus somatic symptoms. These dimensions can coexist, but may also be present separately. The first appears associated with disturbances (under-functioning) in dopamine function; the other appears to be related to a similar under-functioning in the serotonin system. Furthermore, anhedonia itself increasingly appears to be a composite symptom, consisting of at least two dimensions (i.e. a motivational/appetitive and a consummatory one). Depression appears to be characteristically linked more to the first one, in contrast to what was originally thought. We discuss the significance of the above in the evolving treatment of depression and the potential use of dopamine-targeting drugs.

Mood-congruent amygdala responses to subliminally presented facial expressions in major depression: associations with anhedonia

BACKGROUND

Anhedonia has long been recognized as a key feature of major depressive disorders, but little is known about the association between hedonic symptoms and neurobiological processes in depressed patients. We investigated whether amygdala mood-congruent responses to emotional stimuli in depressed patients are correlated with anhedonic symptoms at automatic levels of processing.

METHODS

We measured amygdala responsiveness to subliminally presented sad and happy facial expressions in depressed patients and matched healthy controls using functional magnetic resonance imaging. Amygdala responsiveness was compared between patients and healthy controls within a 2 (group) x 2 (emotion) design. In addition, we correlated patients' amygdala responsiveness to sad and happy facial stimuli with self-report questionnaire measures of anhedonia.

RESULTS

We included 35 patients and 35 controls in our study. As in previous studies, we observed a strong emotion x group interaction in the bilateral amygdala: depressed patients showed greater amygdala responses to sad than happy faces, whereas healthy controls responded more strongly to happy than sad faces. The lack of automatic right amygdala responsiveness to happy faces in depressed patients was associated with higher physical anhedonia scores.

LIMITATIONS

Almost all depressed patients were taking antidepressant medications.

CONCLUSION

We replicated our previous finding of depressed patients showing automatic amygdala mood-congruent biases in terms of enhanced reactivity to negative emotional stimuli and reduced activity to positive emotional stimuli. The altered amygdala processing of positive stimuli in patients was associated with anhedonia scores. The results indicate that reduced amygdala responsiveness to positive stimuli may contribute to anhedonic symptoms due to reduced/inappropriate salience attribution to positive information at very early processing levels.

Major depression duration reduces appetitive word use: an elaborated verbal recall of emotional photographs

INTRODUCTION

Major depressive disorder (MDD) is characterized by cognitive biases in attention, memory and language use. Language use biases often parallel depression symptoms, and contain over-representations of both negative emotive and death words as well as low levels of positive emotive words. This study further explores cognitive biases in depression by comparing the effect of current depression status to cumulative depression history on an elaborated verbal recall of emotional photographs.

METHODS

Following a negative mood induction, fifty-two individuals (42 women) with partially-remitted depression viewed - then recalled and verbally described - slides from the International Affective Picture System (IAPS). Descriptions were transcribed and frequency of depression-related word use (positive emotion, negative emotion, sex, ingestion and death) was analyzed using the Linguistic Inquiry and Word Count program (LIWC).

RESULTS

Contrary to expectations and previous findings, current depression status did not affect word use in any categories of interest. However, individuals with more than 5 years of previous depression used fewer words related to positive emotion (t(50) = 2.10, p = .04, (d = 0.57)), and sex (t(48) = 2.50, p = .013 (d = 0.81)), and there was also a trend for these individuals to use fewer ingestion words (t(50) = 1.95, p = .057 (d = 0.58)), suggesting a deficit in appetitive processing.

CONCLUSIONS

Our findings suggest that depression duration affects appetitive information processing and that appetitive word use may be a behavioral marker for duration related brain changes which may be used to inform treatment.

Anhedonia: a concept analysis

Anhedonia presents itself in a myriad of disease processes. To further develop our understanding of anhedonia and effective ways to manage it, the concept requires clear boundaries. This paper critically examined the current scientific literature and conducted a concept analysis of anhedonia to provide a more accurate and lucid understanding of the concept. As part of the concept analysis, this paper also provides model, borderline, related, and contrary examples of anhedonia.

Reduced hedonic capacity in euthymic bipolar subjects: a trait-like feature?

BACKGROUND

The aim of our study was to assess hedonic capacity in euthymic bipolar subjects, identifying possible differences compared to remitted unipolar depressed patients and healthy controls.

METHODS

107 subjects with bipolar disorders, 86 with major depressive disorder and 106 healthy controls, homogeneous with respect to demographic characteristics, were enrolled. The following scales were administered: the Snaith-Hamilton pleasure scale (SHAPS), the subscale for 'anhedonia/asociality' of the scale for the assessment of negative symptoms (SANS) and the visual analogue scale (VAS) for hedonic capacity.

RESULTS

Scores on SHAPS total, interests and social interactions, SANS 'anhedonia/asociality' and VAS were all significantly higher in affective disorder patients compared to healthy controls. No difference was found between clinical groups. 20.5% (n=22) of bipolar disorder subjects and 24.5% (n=21) of major depressed subjects showed a significant reduction in hedonic capacity (SHAPS total score ≥ 3), compared to 7.5% (n=8) of healthy controls (χ(2)=12.03; p=.002).

LIMITATIONS

Limitations include heterogeneity with respect to pharmacological status and longitudinal course (i.e., 'single' vs. 'recurrent' affective episodes).

CONCLUSIONS

The major finding of our study is that euthymic bipolar patients and remitted major depressed patients display residual anhedonic symptoms. This suggests that, in affective disorder patients, altered hedonic capacity could represent an enduring trait and that, possibly, dysfunctions in the neurobiological mechanisms underlying hedonic response and reward processing persist, irrespective of mood state.

Disrupted-in-schizophrenia-1 Gln31Leu polymorphism results in social anhedonia associated with monoaminergic imbalance and reduction of CREB and β-arrestin-1,2 in the nucleus accumbens in a mouse model of depression

Disrupted-in-schizophrenia-1 (DISC1) is associated with mental disorders, including major depression. We previously showed that DISC1-Q31L mutant mice have depression-like behaviors and can therefore be used to study neurobiological mechanisms of depression and antidepressant (AD) medication action. First, we found reduced levels of dopamine, serotonin and norepinephrine in the nucleus accumbens (NAC) of DISC1-Q31L mutants. Next, we assessed social-conditioned place preference as a reward-dependent task and the capacity of distinct ADs to correct impaired social behavior in DISC1-Q31L mice. Bupropion, but not fluoxetine or desipramine, was able to correct deficient social facilitation, social reward, and social novelty in DISC1-Q31L mutants, whereas all three ADs were able to improve social motivation and behavioral despair in DISC1-Q31L mutants. Furthermore, we sought to correlate social anhedonia with molecular and cellular features including dendritic spine density, β-arrestin-1,2, and cAMP-response-element-binding protein (CREB) in the NAC as biomarkers related to depression and the DISC1 pathway. DISC1-Q31L mutants showed reduced levels of β-arrestin-1,2, CREB, and spine density in the NAC, further supporting the construct validity of the genetic model. Bupropion induced the greatest effect on CREB in DISC1-Q31L mutants, whereas all studied ADs corrected the reduced levels of β-arrestin-1,2 and modestly ameliorated deficient spine density in this brain region. Overall, we find neurobiological changes accompanying social anhedonia in the NAC of DISC1-Q31L mutant mice, consistent with a role for DISC1 in regulating social reward as an endophenotype of depression.

Altered social hedonic processing in eating disorders

OBJECTIVE

Exploring social anhedonia in eating disorders (ED) was the main objective of this study. Social anhedonia relates to a reduced feeling of pleasure from social stimulation. Researching the exact nature of problems in interpersonal relationships is an important topic for clinicians and researchers in the field.

METHOD

The revised social anhedonia scale was completed by 148 participants: anorexia nervosa (AN) n = 72; bulimia nervosa (BN) n = 19; recovered AN n = 14; healthy controls (HC) n = 43. Participants also completed mood related measures and the Toronto Alexythimia scale.

RESULTS

People with AN and BN had higher self-reported social anhedonia than people without ED. Recovered AN had an intermediate profile in between AN and HC. Clinical severity and alexithymia were strongly associated with social anhedonia scores.

DISCUSSION

Difficulty identifying and expressing feelings could be related to this diminished drive for social pleasure. Tackling these interpersonal maintaining factors in treatment is likely to be a worthwhile endeavor.

Clinical utility of the Snaith-Hamilton-Pleasure scale in the Chinese settings

BACKGROUND

The Snaith-Hamilton-Pleasure-Scale (SHAPS) is a self-reported scale evaluating anhedonia for neuropsychiatric disorders. It has demonstrated with impressive psychometric properties and advantages in its applicability over other similar instruments. However, very few studies have been conducted to examine the clinical utility of the SHAPS in the context of Chinese settings. The current study aimed to examine the clinical utility of the translated version of the SHAPS in the Chinese clinical settings.

METHODS

A Chinese version of SHAPS was administered to 336 college students to examine the internal consistency and test-retest reliability at a 4-week interval. Moreover, the translated SHAPS was also administered to 141 patients with major depression, 72 patients with schizophrenia, and 72 healthy controls to examine its clinical discrimination.

RESULTS

The internal consistency of the SHAPS for the non-clinical sample and test-retest reliability at a 4- week interval were 0.85 and 0.64, respectively. Moreover, the SHAPS also showed an excellent internal consistency (alpha was 0.93) and a one-factor solution with the first factor accounted for 51.53% of the variance in the clinical psychiatric samples. ANOVA of the SHAPS total score indicated that the patients with depression scored significantly more anhedonia than the patients with schizophrenia and healthy controls (p<0.001), and the patients with schizophrenia scored significantly more anhedonia than the healthy controls (P<0.02).

CONCLUSIONS

These findings suggest that the Chinese version of the SHAPS is a useful and promising instrument in assessing anhedonia for clinical patients and non-clinical individuals in the Chinese settings.

Trait and state positive emotional experience in schizophrenia: a meta-analysis

BACKGROUND

Prior meta-analyses indicated that people with schizophrenia show impairment in trait hedonic capacity but retain their state hedonic experience (valence) in laboratory-based assessments. Little is known about what is the extent of differences for state positive emotional experience (especially arousal) between people with schizophrenia and healthy controls. It is also not clear whether negative symptoms and gender effect contribute to the variance of positive affect.

METHODS AND FINDINGS

The current meta-analysis examined 21 studies assessing state arousal experience, 40 studies measuring state valence experience, and 47 studies assessing trait hedonic capacity in schizophrenia. Patients with schizophrenia demonstrated significant impairment in trait hedonic capacity (Cohen's d = 0.81). However, patients and controls did not statistically differ in state hedonic (valence) as well as exciting (arousal) experience to positive stimuli (Cohen's d = -0.24 to 0.06). They also reported experiencing relatively robust state aversion and calmness to positive stimuli compared with controls (Cohen's d = 0.75, 0.56, respectively). Negative symptoms and gender contributed to the variance of findings in positive affect, especially trait hedonic capacity in schizophrenia.

CONCLUSIONS

Our findings suggest that schizophrenia patients have no deficit in state positive emotional experience but impairment in "noncurrent" hedonic capacity, which may be mediated by negative symptoms and gender effect.

Neurogenetics of depression: a focus on reward processing and stress sensitivity

Major depressive disorder (MDD) is etiologically complex and has a heterogeneous presentation. This heterogeneity hinders the ability of molecular genetic research to reliably detect the small effects conferred by common genetic variation. As a result, significant research efforts have been directed at investigating more homogenous intermediate phenotypes believed to be more proximal to gene function and lie between genes and/or environmental effects and disease processes. In the current review we survey and integrate research on two promising intermediate phenotypes linked to depression: reward processing and stress sensitivity. A synthesis of this burgeoning literature indicates that a molecular genetic approach focused on intermediate phenotypes holds significant promise to fundamentally improve our understanding of the pathophysiology and etiology of depression, which will be required for improved diagnostic definitions and the development of novel and more efficacious treatment and prevention strategies. We conclude by highlighting challenges facing intermediate phenotype research and future development that will be required to propel this pivotal research into new directions.

Anhedonia is an important factor of health-related quality-of-life deficit in schizophrenia and schizoaffective disorder

The aim of the current study was to investigate an association of physical and social hedonic deficits with health-related quality of life (HRQL), controlling for related distressing and protective factors. Eighty-seven stable patients with schizophrenia (SZ) and schizoaffective disorder (SA) were assessed using the revised Physical Anhedonia Scale (PAS) and the Social Anhedonia Scale (SAS), the Quality of Life Enjoyment and Life Satisfaction Questionnaire (Q-LES-Q), and related factors. Hedonic and HRQL deficit scores did not reach significant differences between SZ and SA patients. General and domain-specific Q-LES-Q scores were significantly correlated with PAS and SAS scores independent of the adverse effects and psychopathological symptoms. Dissatisfaction with HRQL increased from "normal hedonics" (4.8%) to "hypohedonics" (28.6%) and "double anhedonics" (66.7%). Permanently dissatisfied patients who revealed deterioration in general quality of life across 10 years had significantly higher PAS and SAS scores than did patients who were permanently satisfied and improved. An exploratory factor analysis yielded a three-factor solution; PAS and SAS scores were joined to the second factor together with Q-LES-Q, self-efficacy, coping styles, and social support scores. PAS scores accounted for 7% to 13% of the total variance in three domains and in the general quality-of-life alterations. SAS scores did not predict variability in the Q-LES-Q domains. Therefore, physical and social hedonic deficits significantly associated with poor HRQL independent of the adverse effects and psychopathological symptoms of SZ/SA. Physical anhedonia may be a predictor for quality-of-life deficit.

Reconsidering anhedonia in depression: lessons from translational neuroscience

Anhedonia is a core symptom of major depressive disorder (MDD), the neurobiological mechanisms of which remain poorly understood. Despite decades of speculation regarding the role of dopamine (DA) in anhedonic symptoms, empirical evidence has remained elusive, with frequent reports of contradictory findings. In the present review, we argue that this has resulted from an underspecified definition of anhedonia, which has failed to dissociate between consummatory and motivational aspects of reward behavior. Given substantial preclinical evidence that DA is involved primarily in motivational aspects of reward, we suggest that a refined definition of anhedonia that distinguishes between deficits in pleasure and motivation is essential for the purposes of identifying its neurobiological substrates. Moreover, bridging the gap between preclinical and clinical models of anhedonia may require moving away from the conceptualization of anhedonia as a steady-state, mood-like phenomena. Consequently, we introduce the term "decisional anhedonia" to address the influence of anhedonia on reward decision-making. These proposed modifications to the theoretical definition of anhedonia have implications for research, assessment and treatment of MDD.