A Prospective Study for Prediction of Psychotic Relapse Using the Korean Early Signs Scale in Patients With Schizophrenia.

INTRODUCTION: A psychotic relapse of schizophrenia is commonly preceded by nonpsychotic behavioral symptoms and signs, and detection of these early signs may enable prevention of relapse of schizophrenia. This study aimed to test the predictive validity of a Korean version of Early Signs Scale (K-ESS) for psychotic relapse for detecting the early signs. MATERIALS AND METHODS: In this multicenter noninterventional 52-week prospective study, outpatients diagnosed as having schizophrenia within 5 years were recruited. The K-ESS and Clinical Global Impression-Severity (CGI-S) scale were administered monthly until the end of the study or the relapse. The primary objective was to determine an optimal cutoff point of K-ESS score for prediction of psychotic relapse. The secondary objective was to assess the concurrent validity of the K-ESS using CGI-S scale. RESULTS: Among the 162 included patients, 14 (8.6%) relapsed during the 52-week study period. The optimal cutoff score of K-ESS was 15 with a sensitivity of 71.43% and a specificity of 52.70%, indicating poor predictive accuracy of K-ESS. A lower cutoff K-ESS score of 3 and a higher cutoff score of 28 were found in the subgroups with milder (CGI-S = 1-2) and severer (CGI-S = 3-4) symptom severity, respectively, with fair to good predictive accuracy. The K-ESS showed acceptable concurrent validity with CGI-S and concordance rate between self-rated and informant-rated scores. DISCUSSION: The predictive accuracy of K-ESS was limited by evaluation interval of a month. At least fortnightly follow-up would be needed for detection of early signs to prevent a psychotic relapse in schizophrenia.

Perceptions of social dominance through facial emotion expressions in euthymic patients with bipolar I disorder.

The ability to accurately perceive dominance in the social hierarchy is important for successful social interactions. However, little is known about dominance perception of emotional stimuli in bipolar disorder. The aim of this study was to investigate the perception of social dominance in patients with bipolar I disorder in response to six facial emotional expressions. Participants included 35 euthymic patients and 45 healthy controls. Bipolar patients showed a lower perception of social dominance based on anger, disgust, fear, and neutral facial emotional expressions compared to healthy controls. A negative correlation was observed between motivation to pursue goals or residual manic symptoms and perceived dominance of negative facial emotions such as anger, disgust, and fear in bipolar patients. These results suggest that bipolar patients have an altered perception of social dominance that might result in poor interpersonal functioning. Training of appropriate dominance perception using various emotional stimuli may be helpful in improving social relationships for individuals with bipolar disorder.

Manic patients exhibit more utilitarian moral judgments in comparison with euthymic bipolar and healthy persons.

Both emotional and cognitive processes are involved in moral judgments. Ventromedial prefrontal lesions are related to impaired prosocial emotions and emotional dysregulation, and patients with these lesions exhibit increased utilitarian judgments of emotionally salient personal moral dilemmas. Bipolar patients experiencing manic episode also have impaired emotional regulation and behavioral control. We investigated the characteristics of moral judgment in manic and euthymic patients with bipolar disorder using the 50 hypothetical moral dilemma task (17 non-moral, 20 personal, and 13 impersonal). Our study included 27 manic bipolar patients, 26 euthymic bipolar patients, and 42 healthy controls. Subjects were instructed to determine whether or not each dilemma was morally acceptable, and their reaction times were recorded. Manic patients showed significantly greater utilitarian judgment than euthymic patients and normal controls for personal moral dilemmas. However, there were no significant between-group differences for the non-moral and impersonal moral dilemmas. Our results suggest that increased utilitarian judgments of personal moral dilemmas may be a state-related finding observed only in manic patients. This difference in moral judgment assessments may reflect the decision-making characteristics and underlying neurobiological mechanisms of bipolar disorder, especially during the manic state.

Autobiographical memory and its association with neuropsychological function in bipolar disorder.

OBJECTIVE: The aim of this study was to investigate the overgeneralization of autobiographical memory (AM) in bipolar disorder (BD) and assess its association with multiple cognitive domains. METHOD: Twenty-eight clinically stable bipolar I patients and an equal number of age- and gender-matched healthy controls (HC) were included. All participants were examined using the autobiographical memory test (AMT) and the neuropsychological battery including the general intelligence, attention, verbal memory, verbal fluency, visual memory, and executive functions domain. Demographic, clinical, and test variables were compared between BD and HC groups. Correlation analyses of AMT scores with cognitive functions were performed within each group, controlling for demographic and clinical variables. RESULTS: Total and negative scores of AMT were significantly lower in BD patients compared to HC individuals. AMT scores were significantly correlated with WAIS similarities, WCST perseverative errors, and WCST categories completed in BD, whereas AMT scores were correlated with verbal memory and verbal fluency in HC. CONCLUSION: Our findings suggest that overgeneral AM is a characteristic of BD and is related to executive function. Future studies should investigate the benefit of additional treatment focusing on overgeneral AM in BD.

Assessment of implicit self-esteem in bipolar manic and euthymic patients using the implicit association test.

OBJECTIVE: Although self-esteem is thought to be an important psychological factor in bipolar disorder, little is known about implicit and explicit self-esteem in manic patients. In this study, we investigated differences in implicit and explicit self-esteem among bipolar manic patients, bipolar euthymic patients, and healthy controls using the Implicit Association Test (IAT). METHODS: Participants included 19 manic patients, 27 euthymic patients, and 27 healthy controls. Participants completed a self-esteem scale to evaluate explicit self-esteem and performed the self-esteem IAT to evaluate implicit self-esteem. RESULTS: There were no differences among groups in explicit self-esteem. However, there were significant differences among groups in implicit self-esteem. Manic patients had higher IAT scores than euthymic patients and a trend toward higher IAT scores than healthy controls. CONCLUSIONS: Our findings suggest that, on the latent level, a manic state is not simply the opposite of a depressed state. Furthermore, there may be a discontinuity of implicit self-esteem between manic and euthymic states. These unexpected results may be due to characteristics of the study participants or the methods used to assess implicit self-esteem. Nevertheless, they provide greater insights on the psychological status of manic patients.

An exploratory study on spatiotemporal clustering of suicide in Korean adolescents.

BACKGROUND: Adolescent suicides are more likely to form clusters than those of other age groups. However, the definition of a cluster in the space-time dimension has not been established, neither are the factors contributing to it well known. Therefore, this study aimed to identify space-time clusters in adolescent suicides in Korea and to examine the differences between clustered and non-clustered cases using novel statistical methods. METHODS: From 2016 to 2020, the dates and locations, including specific addresses from which the latitude and longitude of all student suicides (aged 9-18 years) in Korea were obtained through student suicide reports. Sociodemographic characteristics of the adolescents who died by suicide were collected, and the individual characteristics of each student who died by suicide were reported by teachers using the Strengths and Difficulties Questionnaire (SDQ). Density-Based Spatial Clustering of Applications with Noise (DBSCAN) analysis was used to assess the clustering of suicides. RESULTS: We identified 23 clusters through the data analysis of 652 adolescent suicides using DBSCAN. By comparing the size of each cluster, we identified 63 (9.7%) spatiotemporally clustered suicides among adolescents, and the temporal range of these clusters was 7-59 days. The suicide cluster group had a lower economic status than the non-clustered group. There were no significant differences in other characteristics between the two groups. CONCLUSION: This study has defined the space-time cluster of suicides using a novel statistical method. Our findings suggest that when an adolescent suicide occurs, close monitoring and intervention for approximately 2 months are needed to prevent subsequent suicides. Future research using DBSCAN needs to involve a larger sample of adolescents from various countries to further corroborate these findings.

Prodromes and coping types in bipolar patients with nonpsychotic or psychotic mania.

BACKGROUND: Bipolar disorder is a recurrent and cyclical illness frequently accompanied by psychotic symptoms. Detecting prodromes and enhancing coping skills for prodromal symptoms in bipolar patients are very important for relapse prevention. Psychotic features in bipolar patients are related to poor prognosis. We aimed to investigate the differences in prodromal symptoms and coping styles in psychotic and nonpsychotic bipolar patients. METHODS: Eighty-three euthymic bipolar patients with or without a history of manic psychosis were interviewed about their demographic, diagnostic, and clinical information and completed a 40-item checklist for prodromal symptoms. After the interview, they completed the Coping Inventory for Prodromes of Mania. RESULTS: The differences between the psychotic patients and the nonpsychotic patients were found in the prodromal durations, and a few prodromal symptoms such as afraid of going crazy (P = .03), energetic-very active (P = .01), and hearing hallucination (P = .02). The psychotic patients showed a higher score of denial or blame than the nonpsychotic ones (1.92 ± 0.73 in nonpsychosis, 2.32 ± 0.84 in psychosis; P = .03). Logistic regression revealed that the duration of prodromes (P = .02) and hearing hallucination (P = .01) were related to the presence of psychotic features. CONCLUSION: Psychotic patients had a tendency to use denial or blame coping strategy and to experience attenuated psychotic symptoms a little more during the prodromal period. Timely psychosocial approaches for detecting signs and enhancing coping strategies would improve the outcomes.

Cognitive profiles in bipolar I disorder and associated risk factors: Using Wechsler adult intelligence scale-IV.

Background: Despite the growing evidence of cognitive impairments in bipolar disorder (BD), little work has evaluated cognitive performances utilizing the latest version of the Wechsler Intelligence Scale-IV (WAIS-IV), which is one of the most widely used neurocognitive assessments in clinical settings. Furthermore, clinical characteristics or demographic features that negatively affect the cognitive functioning of BD were not systematically compared or evaluated. Accordingly, the present study aimed to examine the cognitive profile of bipolar I disorder (BD-I) patients and associated risk factors. Methods: Participants included 45 patients, diagnosed with BD-I, current or most recent episode manic, and matching 46 healthy controls (HC). Cognitive performance was evaluated via WAIS-IV, and clinical characteristics of the BD-I group were examined via multiple self- and clinician-report questionnaires. Results: Multivariate analysis of covariance (MANCOVA) results indicated that the BD-I group demonstrated significantly poorer performance compared to the HC group in subtests and indexes that reflect working memory and processing speed abilities. Redundancy analysis revealed that overall symptom severity, manic symptom severity, and anxiety were significant predictors of cognitive performance in BD-I, while age of onset, past mood disorder history, depression severity, and impulsiveness showed comparatively smaller predictive values. Conclusion: The current study suggests cognitive deterioration in the cognitive proficiency area while generalized ability, including verbal comprehension and most of the perceptual reasoning skills, remain intact in BD-I. The identified risk factors of cognitive performance provide specific clinical recommendations for intervention and clinical decision-making.

Different patterns of white matter microstructural alterations between psychotic and non-psychotic bipolar disorder.

This study aimed to investigate alterations in white matter (WM) microstructure in patients with psychotic and non-psychotic bipolar disorder (PBD and NPBD, respectively). We used 3T-magnetic resonance imaging to examine 29 PBD, 23 NPBD, and 65 healthy control (HC) subjects. Using tract-based spatial statistics for diffusion tensor imaging data, we compared fractional anisotropy (FA) and mean diffusion (MD) pairwise among the PBD, NPBD, and HC groups. We found several WM areas of decreased FA or increased MD in the PBD and NPBD groups compared to HC. PBD showed widespread FA decreases in the corpus callosum as well as the bilateral internal capsule and fornix. However, NPBD showed local FA decreases in a part of the corpus callosum body as well as in limited regions within the left cerebral hemisphere, including the anterior and posterior corona radiata and the cingulum. In addition, both PBD and NPBD shared widespread MD increases across the posterior corona radiata, cingulum, and sagittal stratum. These findings suggest that widespread WM microstructural alterations might be a common neuroanatomical characteristic of bipolar disorder, regardless of being psychotic or non-psychotic. Particularly, PBD might involve extensive inter-and intra-hemispheric WM connectivity disruptions.

Reliability and Validity of the Korean Version of Disruptive Behavior Disorders Rating Scale, DSM-5 Version-Parent Form.

OBJECTIVE: Disruptive behavior disorder (DBD) adversely impacts children and adolescents. However, a comprehensive and cost-effective scale to assess DBD is lacking in Korea. Therefore, this study translated the Disruptive Behavior Disorders Rating Scale (DBDRS) into Korean and analyzed its psychometric properties. METHODS: Parents and primary caregivers of non-clinical (n=429) and clinical (n=28) children and adolescents aged 6-15 years were included in the analysis. Confirmatory factor analysis was conducted; further, concurrent validity and internal consistency were investigated using correlation analysis and Cronbach's alpha, respectively. Furthermore, discriminative capacity was estimated using receiver operating characteristic curve analysis. RESULTS: The four-factor model of K-DBDRS showed good model fit indices and factor loadings, which supported the construct validity of the scale. Strong correlations between K-DBDRS and related measurements were observed, and a robust level of Cronbach's alpha was confirmed (0.891-0.933). The discriminative capacity of the scale was good, based on the area under the curve values (0.933-0.953). CONCLUSION: This study indicated that the K-DBDRS is an appropriate screening tool for Korean children and adolescents. Thus, this scale can be applied in clinical and community settings to identify children and adolescents with disruptive behavior disorders.

Altered behavioral and electrophysiological responses to social fairness in manic and euthymic patients with bipolar disorder.

BACKGROUND: Individuals with bipolar disorder show mood instability, including heightened anger and impulsivity. The Ultimatum Game (UG) is a tool used to evaluate emotional and social decision-making strategies. We investigated behavioral and electrophysiological responses to subjectively fair or unfair offers in the UG in patients with bipolar I disorder. METHODS: Twenty-four manic patients, 20 euthymic patients, and 30 healthy controls participated in this study. We analyzed their behaviors and collected electroencephalography data with which to analyze feedback-related negativity (FRN) as they played in the UG as responders. RESULTS: Manic patients exhibited significantly higher rejection rates for unfair offers than euthymic patients and healthy controls. Healthy individuals exhibited a greater (i.e., more negative) FRN amplitude in response to unfair offers than to fair offers, whereas euthymic patients exhibited a greater FRN amplitude in response to fair offers compared with unfair offers. Manic patients exhibited no difference in FRN amplitudes between fair and unfair offers. CONCLUSIONS: The current data suggest that different behavioral responses and FRN amplitude patterns can be associated with characteristic manifestations of mood instability in manic bipolar patients. In addition, electrophysiological alterations in response to unfair offers may be a trait abnormality independent of mood state.

Psychometric Properties of the Korean Version of the Mental Health Professionals Stress Scale.

Background: Job stress of mental health professionals can have a negative impact on them, particularly their psychological health and mortality, and may also affect organizations' and institutions' ability to provide quality mental health services to patients. Aim: This study aimed to: (1) investigate the validity and reliability of the Korean Mental Health Professionals Stress Scale (K-MHPSS), (2) develop K-MHPSS cut-off points to measure clinical depression and anxiety, and (3) examine whether specific stressors vary by area of expertise. Methodology: Data were collected via an online survey over 3 months, from August to October 2020. An online survey using a survey website was administered to volunteers who accessed the link and consented to participate. Data from 558 participants (200 clinical psychologists, 157 nurses, and 201 social workers) were included in the final analysis. Confirmatory and exploratory factor analyses were conducted to examine the factor structure of the K-MHPSS; concurrent validity of the scale was determined by analyzing correlation; internal consistency was determined by Cronbach's alpha coefficient. In addition, ROC curve analysis and Youden's index were used to estimate optimal cut-off points for K-MHPSS; one-way ANOVA was performed to investigate the difference among the three groups. Results: The seven-factor model of the original scale did not be replicated by Korean mental health professionals. The K-MHPSS had the best fit with the six-factor model, which consists of 34 items. Concurrent validity was confirmed, and overall reliability was found to be good. The K-MHPSS cut-off points for depression and anxiety appeared to slightly different by professional groups. Furthermore, nurses and social workers showed significantly higher total scores compared to clinical psychologists, and there are significant differences in subscale scores among professionals. Conclusion: The Korean version of the MHPSS has appropriate psychometric properties and can be used to assess the occupational stress of mental health professionals. It can also serve as a reference point for screening clinical level of depression and anxiety in mental health professionals.

Manipulation ability of internal representation in patients with euthymic bipolar I disorder and schizophrenia using a mental rotation task.

BACKGROUND: A growing body of literature has suggested that effective emotion regulation is influenced by cognitive function. Maintenance and manipulation of internal representations occur in working memory (WM), and impairments of WM have been reported in patients with bipolar disorder. METHODS: We examined the manipulation ability of internal representations in WM using mental rotation (MR) tasks, and compared the task performances of euthymic bipolar I disorder patients to those of schizophrenia patients and healthy controls. In this study, 20 euthymic bipolar I disorder patients, 20 schizophrenia patients, and 38 healthy controls were recruited. People and letter MR tasks were employed to evaluate the ability of WM manipulation. RESULTS: Compared to healthy controls, euthymic bipolar I disorder patients showed substantially higher error rates of people MR task and slower responses in both people and letter MR tasks. Schizophrenia patients showed no difference in error rate and response time in MR tasks compared to healthy controls; however, they showed significantly slower responses in people MR task compared to controls. MR task performance was not different between euthymic bipolar and schizophrenia patients. CONCLUSION: Our study results indicate that manipulation of internal representation, especially in the egocentric MR, is impaired in bipolar disorder even in the emotionally-stable state. We speculate that impaired imagery manipulation might be related to alterations in empathic ability, susceptibility of mental imagery, and emotion regulation strategies observed in bipolar disorder.

Cortical Volumetric Correlates of Childhood Trauma, Anxiety, and Impulsivity in Bipolar Disorder.

OBJECTIVE: More recently, attention has turned to the linkage between childhood trauma and emotional dysregulation, but the evidence in bipolar disorder (BD) is limited. To determine neurobiological relationships between childhood trauma, current anxiety, and impulsivity, we investigated cortical volumetric correlates of these clinical factors in BD. METHODS: We studied 36 patients with DSM-5 BD and 29 healthy controls. Childhood trauma, coexisting anxiety, and impulsivity were evaluated with the Korean version-Childhood Trauma Questionnaire (CTQ), the Korean version-Beck Anxiety Inventory (BAI), and the Korean version-Barratt Impulsiveness Scale (BIS). Voxel-based morphometry (VBM) was used to assess gray matter volume (GMV) alterations on the brain magnetic resonance imaging (MRI). Partial correlation analyses were conducted to examine associations between the GMV and each scale in the BD group. RESULTS: Childhood trauma, anxiety, and impulsivity were interrelated in BD. BD patients revealed significant inverse correlations between the GMV in the right precentral gyrus and CTQ scores (r=-0.609, p<0.0003); between the GMV in the left middle frontal gyrus and BAI scores (r=-0.363, p=0.044). Moreover, patients showed similar tendency of negative correlations between the GMV in the right precentral gyrus and BIS scores; between the GMV in the left middle frontal gyrus and CTQ scores. CONCLUSION: The present study provides evidence for a neural basis between childhood trauma and affect regulations in BD. The GMV alterations in multiple frontal lobe areas may represent neurobiological markers for anticipating the course of BD.

Low working memory capacity in euthymic bipolar I disorder: No relation to reappraisal on emotion regulation.

BACKGROUND: Emotion regulation (ER) applies behavioral and cognitive strategies to modify the appearance and intensity of emotions. Working memory capacity (WMC) plays an important role in the ER process, particularly through its influence on the efficiency of ER strategies. METHODS: We investigated interactions between WMC and three ER strategies, namely cognitive reappraisal, expressive suppression, and rumination, in 43 euthymic patients with bipolar I disorder and 48 healthy control subjects. We used the Korean versions of the Operation Span Task, Emotion Regulation Questionnaire, Ruminative Response Scale, and Difficulties in Emotion Regulation Scale. RESULTS: WMC modulated the efficacy of cognitive reappraisal in healthy controls with high WMC, but not in patients with bipolar disorder. There were no significant interactions between WMC and expressive suppression or rumination in either group. LIMITATIONS: These include the small sample size, use of neutral words to evaluate negative emotion, use of self-administered questionnaires, and relatively high cut-off for the definition of euthymic states. A number of uncontrolled factors may have influenced our results including patients' duration of remission, number of episodes, psychiatric family history, and current psychiatric medications. CONCLUSIONS: Our findings suggest that working memory does not function effectively in the reappraisal process during ER in patients with bipolar disorder. This may indicate that top-down regulation of emotion is impaired in bipolar disorder. Cognitive interventions aimed at improving ER in such patients may be ineffective.

Changes in antipsychotic drug usage and factors affecting the use of typical drugs based on nationwide health insurance data in South Korea.

OBJECTIVES: To determine changes in antipsychotic drug usage in all South Korean patients with schizophrenia in 2011-2015 and factors affecting their utilisation in 2015. DESIGN AND SETTING: Retrospective cohort study using health insurance claims data on patients with schizophrenia in South Korea in 2011-2015. PARTICIPANTS: All treated patients with schizophrenia in South Korea in 2011-2015. The number of patients with schizophrenia was 171 302 in 2011, 175 488 in 2012, 177 763 in 2013, 180 079 in 2014 and 183 427 in 2015. MAIN OUTCOME MEASURES: Changes in antipsychotic drug usage and factors affecting the use of antipsychotics. RESULTS: Among patients with schizophrenia, there were tendencies of decreased use of antipsychotic combination therapy of typical drugs (from 11.5% to 7.5%) but increased use of combination therapy of atypical drugs (from 21.8% to 29.0%). Factors affecting the use of typical drugs were sex, age, geographical region, type of benefits/insurances and type of medical institutions. Use of typical antipsychotics was increased by age (OR=1.02, 95% CI 1.02 to 1.02). It was higher in men (OR=1.27, 95% CI 1.23 to 1.30) than that in women. It was higher in Medicaid benefiters (OR=4.49, 95% CI 4.35 to 4.64) than that in patients with health insurance. Use of typical drugs was higher among patients treated in general hospitals (OR=1.46, 95% CI 1.32 to 1.64), primary hospitals (OR=3.25, 95% CI 2.95 to 3.59), long-term care hospitals (OR=3.00, 95% CI 2.59 to 3.49) and clinics (OR=8.87, 95% CI 8.06 to 9.76) compared with that in tertiary care hospitals. Compared with metropolitan region, higher use of typical antipsychotics was seen in Gangwon (OR=1.14, 95% CI 1.05 to 1.25), Jeolla (OR=1.32, 95% CI 1.26 to 1.39) and Gyeongsang (OR=1.14, 95% CI 1.10 to 1.18) provinces. CONCLUSIONS: Results of this study confirmed changes of antipsychotic drug usage from typical to atypical antipsychotics in the treatment of schizophrenia and identified factors affecting the use of typical drugs, in contrast with current treatment trend in South Korea. These results may be used in the improvement of a medical system.

Analysis of the Health Insurance Review and Assessment Service data from 2011 to 2015.

BACKGROUND: Schizophrenia is a recurrent, debilitating disease that is rarely curable. Rapid intervention after the first episode of schizophrenia has been shown to positively affect the prognosis. Unfortunately, basic data is scarce on first-episode schizophrenia in Korean patients making it difficult to create a comprehensive list of risk factors for relapse. This study aims to investigate the demographic characteristics and institutional factors of patients with first-episode schizophrenia in order to identify risk factors for relapse. METHODS: Data from the Health Insurance Review & Assessment Service (HIRA) was used for this study to represent the Korean patient population. To identify factors affecting relapse, we explored gender, age, geographic location, medical benefits, type of medical institution, type of medication used, medication adherence, and the severity of symptoms. Data analysis was performed using the Cox proportional hazard model. RESULTS: The number of patients diagnosed with first-episode schizophrenia in Korea over a 2-year period was 4567 of which 1265 (27.7%) patients experienced a relapse during the observational period. Factors affecting relapse included age, type of medical institution, type of medication used, medication adherence, and type of treatment (inpatient or outpatient) after the initial diagnosis, which varied depending upon the severity of symptoms. CONCLUSIONS: It was found that environmental and institutional factors as well as the type of medical treatment were crucial in determining whether patients with first-episode schizophrenia subsequently relapsed. The results of this study can be utilized as source material for directing therapeutic interventions and improving mental health policies in the future.

Correction to: Risk factors for relapse in patients with first-episode schizophrenia: analysis of the Health Insurance Review and Assessment Service data from 2011 to 2015.

[This corrects the article DOI: 10.1186/s13033-018-0187-1.].

Behavioral and Electrophysiological Alterations for Reinforcement Learning in Manic and Euthymic Patients with Bipolar Disorder.

AIMS: Bipolar disorder is characterized by behavioral changes such as risk-taking and increasing goal-directed activities, which may result from altered reward processing. Patients with bipolar disorder show impaired reward learning in situations that require the integration of reinforced feedback over time. In this study, we examined the behavioral and electrophysiological characteristics of reward learning in manic and euthymic patients with bipolar disorder using a probabilistic reward task. METHODS: Twenty-four manic and 20 euthymic patients with bipolar I disorder and 24 healthy control subjects performed the probabilistic reward task. We assessed response bias (RB) as a preference for the stimulus paired with the more frequent reward and feedback-related negativity (FRN) to correct identification of the rich stimulus. RESULTS: Both manic and euthymic patients showed significantly lower RB scores in the early learning stage (block 1) in comparison with the late learning stage (block 2 or block 3) of the task, as well as significantly lower RB scores in the early stage compared to healthy subjects. Relatively more negative FRN amplitude is elicited by no presentation of an expected reward, compared to that elicited by presentation of expected feedback. The FRN became significantly more negative from the early (block 1) to the later stages (blocks 2 and 3) in both manic and euthymic patients, but not in healthy subjects. Changes in RB scores and FRN amplitudes between blocks 2 and 3 and block 1 correlated positively in healthy controls, but correlated negatively in manic and euthymic patients. The severity of manic symptoms correlated positively with reward learning scores and negatively with the FRN. CONCLUSIONS: These findings suggest that patients with bipolar disorder during euthymic or manic states have behavioral and electrophysiological alterations in reward learning compared to healthy subjects. This dysfunctional reward processing may be related to the abnormal decision-making or altered goal-directed activities frequently seen in patients with bipolar disorder.

Design and Methods of the Mood Disorder Cohort Research Consortium (MDCRC) Study.

The Mood Disorder Cohort Research Consortium (MDCRC) study is designed as a naturalistic observational prospective cohort study for early-onset mood disorders (major depressive disorders, bipolar disorders type 1 and 2) in South Korea. The study subjects consist of two populations: 1) patients with mood disorders under 25 years old and 2) patients with mood disorders within 2 years of treatment under 35 years old. After successful screening, the subjects are evaluated using baseline assessments and serial follow-up assessments at 3-month intervals. Between the follow-up assessments, subjects are dictated to check their own daily mood status before bedtime using the eMood chart application or a paper mood diary. At the regular visits every 3 months, inter-visit assessments are evaluated based on daily mood charts and interviews with patients. In addition to the daily mood chart, sleep quality, inter-visit major and minor mood episodes, stressful life events, and medical usage pattern with medical expenses are also assessed. Genomic DNA from blood is obtained for genomic analyses. From the MDCRC study, the clinical course, prognosis, and related factors of early-onset mood disorders can be clarified. The MDCRC is also able to facilitate translational research for mood disorders and provide a resource for the convergence study of mood disorders.