OBJECTIVE: This study aimed to investigate whether aberrant tendency of noncurrent emotion was present in individuals at ultra-high risk (UHR) for psychosis and to explore its associations with various clinical profiles. METHODS: Fifty-seven individuals at UHR and 49 normal controls were enrolled. The tendency of experiencing noncurrent emotion was assessed using various noncurrent emotional self-reported formats, including trait [Neuroticism and Extraversion of the Eysenck Personality Questionnaire], hypothetical (Chapman’s Revised Physical and Social Anhedonia Scales), and retrospective [Anhedonia-Asociality Subscale of the Scale for the Assessment of Negative Symptoms (SANS)] measures. Self-related beliefs (Self-Perception Scale), clinical positive and negative symptoms (SA Positive Symptoms and SANS), psychosocial function (Global Functioning Scale: Role Function and Global Functioning Scale: Social Function) were also examined. RESULTS: Subjects at UHR for psychosis reported more trait unpleasant and less trait pleasant emotions, more hypothetical physical and social anhedonia, and more retrospective anhedonia than normal controls. In UHR, self-perception was correlated to trait unpleasant emotion and hypothetical physical and social anhedonia. Negative symptoms in UHR were associated with hypothetical physical anhedonia and retrospective anhedonia. Global social functioning was related to trait pleasant emotion, hypothetical physical and social anhedonia, and retrospective anhedonia. Neurocognitive function, positive symptoms, and global role functioning were not related with any noncurrent emotional experience measures in UHR. CONCLUSION: These findings suggest that the aberrant tendency of noncurrent emotional experience may be present at the ‘putative’ prodromal phase and are grossly associated with self-related beliefs and psychosocial functioning but not neurocognitive functioning.
Anhedonia ; Extraversion (Psychology) ; Psychotic Disorders* ; Retrospective Studies ; Self Concept

Objective: While recent studies have found deficits in theory of mind (ToM) skills in individuals at ultra-high risk (UHR) for psychosis, empathic tendencies in these subjects remain unclear. The presence of high schizotypy and compromised executive functions, which are found in UHR individuals, would affect ToM skills and empathic tendencies. We investigated the ToM skills and empathic tendencies of UHR individuals and examined their relationship with schizotypy and executive function. Methods: This study included 28 UHR individuals and 28 age- and sex-matched healthy controls. All participants completed a self-reported empathic scale (Interpersonal Reactivity Index) and the Wisconsin Schizotypy Scales. Additionally, the ToM Picture Stories Task and Wisconsin Card Sorting Test were conducted. Results: UHR individuals showed a trend toward lower self-reported empathic tendencies; however, there were no differences in ToM skills between the two groups. Of the four subscales of the IRI, only empathic concern showed a significant difference between the two groups. Empathic concern was inversely associated with negative schizotypy. Conclusion Our findings suggest that UHR individuals show relatively preserved cognitive empathy but compromised emotional empathy. Furthermore, in UHR individuals, the empathic concern subscale of the IRI was associated with negative schizotypy, while ToM skills were related to positive schizotypy and executive function.

Objective: The study was designed to examine the effects of the downregulation of GAD67 expression in the dorsal striatum on reward behavior development. Methods: We evaluated the effects of GAD67 knockdown on depression-like behavior and anxiety using the forced swim test and elevated plus maze test in a mouse model. We further determined the effects of GAD67 knockdown on ketamine- and JWH-018-induced conditioned place preference (CPP). Results: Knockdown of GAD67 in the dorsal striatum of mice increased depression-like behavior, but it decreased anxiety. Moreover, the CPP score on the NMDA receptor antagonist ketamine was increased by GAD67 knockdown, whereas the administration of JWH-018, a cannabinoid receptor agonist, did not affect the CPP score in the GAD67 knockdown mice group compared with the control group. Conclusions and Relevance: These results suggest that striatal GAD67 reduces GABAergic neuronal activity and may cause ketamine-induced NMDA receptor inhibition. Consequently, GAD67 downregulation induces vulnerability to the drug reward behavior of ketamine.

Objective: The study was designed to examine the effects of the downregulation of GAD67 expression in the dorsal striatum on reward behavior development. Methods: We evaluated the effects of GAD67 knockdown on depression-like behavior and anxiety using the forced swim test and elevated plus maze test in a mouse model. We further determined the effects of GAD67 knockdown on ketamine- and JWH-018-induced conditioned place preference (CPP). Results: Knockdown of GAD67 in the dorsal striatum of mice increased depression-like behavior, but it decreased anxiety. Moreover, the CPP score on the NMDA receptor antagonist ketamine was increased by GAD67 knockdown, whereas the administration of JWH-018, a cannabinoid receptor agonist, did not affect the CPP score in the GAD67 knockdown mice group compared with the control group. Conclusions and Relevance: These results suggest that striatal GAD67 reduces GABAergic neuronal activity and may cause ketamine-induced NMDA receptor inhibition. Consequently, GAD67 downregulation induces vulnerability to the drug reward behavior of ketamine.

Objective: The study was designed to examine the effects of the downregulation of GAD67 expression in the dorsal striatum on reward behavior development. Methods: We evaluated the effects of GAD67 knockdown on depression-like behavior and anxiety using the forced swim test and elevated plus maze test in a mouse model. We further determined the effects of GAD67 knockdown on ketamine- and JWH-018-induced conditioned place preference (CPP). Results: Knockdown of GAD67 in the dorsal striatum of mice increased depression-like behavior, but it decreased anxiety. Moreover, the CPP score on the NMDA receptor antagonist ketamine was increased by GAD67 knockdown, whereas the administration of JWH-018, a cannabinoid receptor agonist, did not affect the CPP score in the GAD67 knockdown mice group compared with the control group. Conclusions and Relevance: These results suggest that striatal GAD67 reduces GABAergic neuronal activity and may cause ketamine-induced NMDA receptor inhibition. Consequently, GAD67 downregulation induces vulnerability to the drug reward behavior of ketamine.

Objective: The study was designed to examine the effects of the downregulation of GAD67 expression in the dorsal striatum on reward behavior development. Methods: We evaluated the effects of GAD67 knockdown on depression-like behavior and anxiety using the forced swim test and elevated plus maze test in a mouse model. We further determined the effects of GAD67 knockdown on ketamine- and JWH-018-induced conditioned place preference (CPP). Results: Knockdown of GAD67 in the dorsal striatum of mice increased depression-like behavior, but it decreased anxiety. Moreover, the CPP score on the NMDA receptor antagonist ketamine was increased by GAD67 knockdown, whereas the administration of JWH-018, a cannabinoid receptor agonist, did not affect the CPP score in the GAD67 knockdown mice group compared with the control group. Conclusions and Relevance: These results suggest that striatal GAD67 reduces GABAergic neuronal activity and may cause ketamine-induced NMDA receptor inhibition. Consequently, GAD67 downregulation induces vulnerability to the drug reward behavior of ketamine.

Objective: Relationship between hair cortisol concentration (HCC) and stress-related psychological measures are inconclusive, possibly due to overlooked heterogeneity regarding childhood trauma and a lack of comprehensive research on stress-related psychological factors. This study aims to compare young adults without history of childhood trauma to young adults who experienced childhood trauma using HCC and various stress-related psychological factors, as well as investigate the impacts of childhood trauma on the association between HCC and stress-related psychological measures. Methods: A total of 206 young, healthy adults were recruited. We divided participants into two groups depending on whether or not they had suffered moderate-to-severe childhood trauma (CT+ and CT-) and compared HCC and various stress-related psychological measures between groups. Using multiple linear regression analyses, we assessed the associations between HCC and stress-related psychological measures for each group. Results: We found no difference between the groups in HCC or the reported number of stressful life events in the past year; however, CT+ individuals reported higher stress perception, more depressive and anxiety-related symptoms, and more difficulties in emotion regulation than CT- individuals. HCC was associated with emotion dysregulation among the CT- individuals, but not among the CT+ individuals. Conclusion These findings suggest that history of childhood trauma should be considered in studies using HCC as a biomarker for stress in young adults. Furthermore, HCC might be a useful biomarker of stress and stress-related emotion dysregulation in individuals without moderate-to-severe childhood trauma.

Objectives: Social function deficit is known as a core feature of schizophrenia. This study aimed to investigate differences in empathic tendencies and theory of mind (ToM) skills between healthy controls and young individuals with schizophrenia, and to examine the associations between empathic tendencies, ToM skills and schizotypy, and executive function in schizophrenia. Methods: Thirty patients with schizophrenia and 30 healthy controls were enrolled and assessed using the interpersonal relationship index (IRI; perspective taking, fantasy, empathic concern, and personal distress subscales), ToM-Picture Story Task (ToM-PST; sequence and cognitive questionnaire), Wisconsin schizotypy scale (revised physical anhedonia and perceptual aberration), and Stroop tests for empathic tendencies, ToM skills, schizotypy, and executive function. Results: In individuals with schizophrenia, the IRI for perspective taking and ToM-PST score for cognitive function were lower, and the IRI for personal distress was higher than those in healthy controls. The IRIs for perspective taking and fantasy were related to revised physical anhedonia, and that for empathic concern was associated with revised physical anhedonia and perceptual aberration. The ToM-PST score for sequence was associated with the Stroop test score for schizophrenia. Conclusion These findings indicate deficits in empathic tendencies and ToM skills, which may be independently and primarily associated with schizotypy and executive function in young individuals with schizophrenia.

Objective: The Reading the Mind in the Eyes Test (RMET) was developed by using Caucasian eyes, which may not be appropriate to be used in Korean. The aims of the present study were 1) to develop a Korean version of the RMET (K-RMET) by using Korean eye stimuli and 2) to examine the psychometric properties of the Korean-translated version of the RMET and the K-RMET. Methods: Thirty-six photographs of Korean eyes were selected. A total of 196 (101 females) healthy subjects were asked to take the Korean-translated version of the RMET and K-RMET. To assess internal consistency reliability, Cronbach’s alpha coefficients were computed, and test–retest reliability was assessed by the intraclass correlation coefficient (ICC) and Bland-Altman plots. Confirmatory factor analysis (CFA) and item analysis were also conducted. Results: Internal consistency, measured by Cronbach’s alpha, was 0.542 for the Korean-translated version of the RMET, and 0.540 for the K-RMET. Test–retest reliability (n=25), measured by the ICC, was 0.787 for the Korean-translated version of the RMET, and 0.758 for the K-RMET. In CFA, the assumed single and 3-factor model fit indices were not good in the both types of RMETs. There was difficulty in discrimination in nine items of the Korean-translated version of the RMET and 10 items of the K-RMET. Conclusion The psychometric properties of both the Korean-translated version of the RMET and the K-RMET are acceptable. Both tests are applicable to the clinical population, as well as the general population in Korea.

Objective: The Reading the Mind in the Eyes Test (RMET) is a common measure of the Theory of Mind. Previous studies found a correlation between RMET performance and neurocognition, especially reasoning by analogy; however, the nature of this relationship remains unclear. Additionally, neurocognition was shown to play a significant role in facial emotion recognition. This study is planned to examine the nature of relationship between neurocognition and RMET performance, as well as the mediating role of facial emotion recognition. Methods: One hundred fifty non-clinical youths performed the RMET. Reasoning by analogy was tested by Raven’s Standard Progressive Matrices (SPM) and facial emotion recognition was assessed by the Korean Facial Expressions of Emotion (KOFEE) test. The percentile bootstrap method was used to calculate the parameters of the mediating effects of facial emotion recognition on the relationship between SPM and RMET scores. Results: SPM scores and KOFEE scores were both statistically significant predictors of RMET scores. KOFEE scores were found to partially mediate the impact of SPM scores on RMET scores. Conclusion These findings suggested that facial emotion recognition partially mediated the relationship between reasoning by analogy and social cognition. This study highlights the need for further research for individuals with serious mental illnesses.