Social anhedonia and gamma band abnormalities as a composite/multivariate endophenotype for schizophrenia: a dense array EEG study

Validation of the Korean Version of the Anticipatory and Consummatory Interpersonal Pleasure Scale in Non-help-seeking Individuals

The Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS) is a psychometric instrument that has been used to indirectly measure social anhedonia in many cross-cultural contexts, such as in Western (US), European (French, Spanish), Eastern (Chinese), and Israeli samples. However, little is known about the psychometric properties of the ACIPS in Korean samples. The primary goal of this study was to validate the Korean version of the ACIPS among non-help-seeking individuals. The sample consisted of 307 adult individuals who had no current or prior psychiatric history. Participants were administered the ACIPS, along with the Behavioral Inhibition and Behavioral Activation Scales (BIS/BAS) and Beck Depression Inventory (BDI). We examined the association of the total ACIPS scores with the other measures. The ACIPS showed good internal consistency. We also explored the factor structure of the Korean translation of the ACIPS using principal component analysis with Promax rotation and Kaiser normalization. Factor analysis yielded a three-factor structure that accounted for 58.8% of the variance. The three-factor model included the following subdomains: interactions involving close relationships, casual interactions, and interactions involving family members. Total BAS and BIS scores were significantly associated with total ACIPS scores, while BDI scores were inversely associated with total ACIPS scores. The current research indicates that the Korean version of the ACIPS is a useful and valid scale. Future directions include using the Korean translation of the ACIPS to elucidate the varying degrees of hedonic capacity in psychiatric patients.

A transdiagnostic meta-analysis of physical and social Anhedonia in major depressive disorder and schizophrenia spectrum disorders

INTRODUCTION

Anhedonia is a transdiagnostic construct conceptualized as physical or social, however, the extent to which these subtypes differ across psychotic and mood pathology remains poorly understood. We aimed to quantify the severity of physical and social anhedonia across Major Depressive Disorder (MDD) and Schizophrenia Spectrum Disorder (SSDs).

METHODS

We conducted meta-analyses of the Chapman Physical and Social Anhedonia Scales (PAS;SAS). We reviewed data from participants with MDD, and SSDs separately.

RESULTS

Our first meta-analysis (n = 8 studies, 409 participants) with MDD revealed elevated SAS and PAS in MDD compared to controls. Within-group differences were not significant. Depressive symptom severity moderated the between-group effect of PAS. Our second meta-analysis (n = 44 studies, 3352 participants) revealed elevated SAS and PAS in SSDs compared to controls. We detected a moderate difference between the SAS and PAS within the SSD group. Age moderated within-group differences of SAS and PAS.

DISCUSSION

People with SSD or MDD experience elevated SAS and PAS compared to controls. People with SSDs endorse greater challenges experiencing social rewards relative to physical rewards. People with MDD experience social and physical rewards similarly. The moderating role of depressive symptoms in MDD suggests that physical anhedonia is more state-like than social anhedonia.

The Transdiagnostic Nature of Social Anhedonia: Historical and Current Perspectives

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

Psychotic disorders, dopaminergic agents and EEG/MEG resting-state functional connectivity: A systematic review

Both dysconnectivity and dopamine hypotheses are two well researched pathophysiological models of psychosis. However, little is known about the association of dopamine dysregulation with brain functional connectivity in psychotic disorders, specifically through the administration of antipsychotic medication. In this systematic review, we summarize the existing evidence on the association of dopaminergic effects with electro- and magnetoencephalographic (EEG/MEG) resting-state brain functional connectivity assessed by sensor- as well as source-level measures. A wide heterogeneity of results was found amongst the 20 included studies with increased and decreased functional connectivity in medicated psychosis patients vs. healthy controls in widespread brain areas across all frequency bands. No systematic difference in results was seen between studies with medicated and those with unmedicated psychosis patients and very few studies directly investigated the effect of dopamine agents with a pre-post design. The reported evidence clearly calls for longitudinal EEG and MEG studies with large participant samples to directly explore the association of antipsychotic medication effects with neural network changes over time during illness progression and to ultimately support the development of new treatment strategies.

Resting frontal EEG asymmetry and schizotypal traits: a test-retest study

Introduction: Increase in right relative to left frontal electroencephalography (EEG) activity has been observed in patients with schizophrenia, both in cognitive tasks and during rest; and this lateralisation may be related to the severity of schizotypal traits. Methods: We used the Schizotypal Personality Questionnaire (SPQ) to assess schizotypal traits, and examined the correlation between these traits and resting EEG frontal asymmetry (left-right) in 52 college students, as well as the reliability of this correlation over a three-month interval. Results: A higher total score on the SPQ was correlated with reduced asymmetry in different frequency bands: gamma and beta2 frequency bands at baseline, and delta and alpha frequency bands three months later. Additionally, the reduced left relative to right frontal gamma and beta2 asymmetry was correlated with the participants' verbal fluency ability. However, this correlation was no longer statistically significant after the total SPQ score was controlled. Conclusions: These findings suggest that resting frontal EEG asymmetry is correlated with powers in different frequency bands, and may be an endophenotype for schizophrenia spectrum disorders.

A meta-analysis of self-reported anticipatory and consummatory pleasure in the schizophrenia-spectrum

OBJECTIVE

Recent conceptual frameworks propose anhedonia reflects abnormalities in the temporal dynamics of positive emotion in schizophrenia, characterized by intact consummatory and impaired anticipatory pleasure. A comprehensive meta-analysis can directly test this theory using self-report data.

METHOD

A meta-analysis was performed on studies reporting Temporal Experience of Pleasure Scale (TEPS) data from healthy controls and schizophrenia or schizotypy groups. The TEPS was examined as it contains subscales to measure both consummatory and anticipatory pleasure separately. Statistical heterogeneity and study bias were examined. Meta-regressions evaluated moderators.

RESULTS

53 studies were retrieved (7,797 participants). Results revealed small effect sizes for comparisons of combined schizophrenia/schizotypy and control groups for both consummatory and anticipatory pleasure. Within-group comparisons of pleasure conditions were nonsignificant. The percentage of male schizophrenia/schizotypy participants significantly moderated anticipatory and consummatory pleasure for the combined sample and schizotypy alone; male participants were found to report reduced pleasure. There was only minor evidence of bias; sensitivity analysis confirmed result robustness. Exploratory outlier removal for schizophrenia within-group pleasure comparisons revealed a statistically significant difference between reported anticipatory and consummatory pleasure, with consummatory pleasure reduced relative to anticipatory (i.e., in the opposite direction of the majority of experimental research findings).

CONCLUSIONS

These findings provided only modest support for the temporal dynamics of positive emotion conceptualization because they revealed no evidence for: 1) specific anticipatory pleasure deficits in schizophrenia-spectrum participants compared to controls; 2) significant reductions in anticipatory pleasure relative to consummatory pleasure in schizophrenia-spectrum participants.