Vin Ryu

Differential alteration of automatic semantic processing in treated patients affected by bipolar mania and schizophrenia: an N400 study.

BACKGROUND Various formal thought disorders are presented as symptoms by manic patients including pressure of speech, flight of ideas, and more complex speech with strong emotional components. N400 is the event-related potential, in which amplitude is suggested to be a general index of efforts to retrieve stored semantic context, which depends on the stored representation itself and the retrieval cue stimuli. The present study examines N400 components induced by a word-matching task in manic patients, and compare these responses to those induced by the task in schizophrenia and healthy controls. METHODS Twenty manic patients, twenty schizophrenic patients, and twenty healthy controls performed the word-matching task, in which they were presented with 120 (60 congruent and 60 incongruent) word pairs, they were instructed to discriminate whether each word pair was congruent or incongruent. During the task, we recorded the electroencephalogram. RESULTS Reaction time analysis revealed a main effect for priming, in which reaction times were longer in response to incongruent words than to congruent words in all three participant groups (F=43.1, p<0.001) with no group effects (F=2.3, p=0.11). N400 analysis showed the main effect for priming (F=30.2, p<0.001), for group (F=5.0, p=0.01), and the interaction of priming×group (F=4.6, p=0.02). Post-hoc analysis of this interaction revealed larger N400 amplitudes to congruent words in manic patients (F=4.0, p=0.02) and smaller N400 to incongruent words in schizophrenic patients than in other groups (F=6.1, p=0.004). No correlations were found between N400 and symptom severity within patient groups. CONCLUSIONS These findings suggest that priming effects of contextually related word pairs are decreased in patients with bipolar mania, whereas priming N400 responses of contextually unrelated word pairs are increased in schizophrenia. This may be the neurophysiological evidence of abnormal automatic semantic processing in patients with bipolar mania, and it also reflects a qualitative difference in thought and speech disorders between bipolar manic and schizophrenia.

Initial Depressive Episodes Affect the Risk of Suicide Attempts in Korean Patients with Bipolar Disorder.

Purpose Suicide is a major concern for increasing mortality in bipolar patients, but risk factors for suicide in bipolar disorder remain complex, including Korean patients. Medical records of bipolar patients were retrospectively reviewed to detect significant clinical characteristics associated with suicide attempts. Materials and Methods A total of 579 medical records were retrospectively reviewed. Bipolar patients were divided into two groups with the presence of a history of suicide attempts. We compared demographic characteristics and clinical features between the two groups using an analysis of covariance and chi-square tests. Finally, logistic regression was performed to evaluate significant risk factors associated with suicide attempts in bipolar disorder. Results The prevalence of suicide attempt was 13.1% in our patient group. The presence of a depressive first episode was significantly different between attempters and nonattempters. Logistic regression analysis revealed that depressive first episodes and bipolar II disorder were significantly associated with suicide attempts in those patients. Conclusion Clinicians should consider the polarity of the first mood episode when evaluating suicide risk in bipolar patients. This study has some limitations as a retrospective study and further studies with a prospective design are needed to replicate and evaluate risk factors for suicide in patients with bipolar disorder.

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.

Effects of Color Temperature and Brightness on Electroencephalogram Alpha Activity in a Polychromatic Light-emitting Diode.

Objective It has been reported that working and learning efficiency might be increased through artificially controlling the color temperature and brightness of light. However, the neurological bases of these outcomes are not well established. Our study was designed to observe whether electroencephalogram (EEG) alpha frequency, as a candidate biological marker, demonstrates significant changes in response to alterations of specific light parameters. Methods Thirty-two healthy subjects performed cognitive tasks under four different polychromatic light conditions: a combination of two different levels of color temperature (2766K vs. 5918K) and brightness (300 lux vs. 600 lux). Spectrum analyses were performed on alpha frequency. Results Subjects reported that they felt more pleasant in bright conditions and more relaxed in warm color temperature conditions. Our findings indicate that alpha power increases in warm, low-light and cool, high-light conditions, and there is a significant interaction between color temperature and brightness. Conclusion EEGs might serve as a useful biological marker for further research related to the effects of polychromatic light on cognitive function.

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.

Effects of emotional stimuli on time perception in manic and euthymic patients with bipolar disorder

BACKGROUND Time perception, which plays a fundamental role in decision-making and the evaluation of the environment, is also influenced by emotions. Patients with bipolar disorder have impairments in emotional processing as well as interval timing. We investigated the effects of emotional stimuli on time estimation and reproduction in manic and euthymic bipolar patients compared with healthy controls. METHODS We recruited 22 manic bipolar patients, 24 euthymic bipolar patients and 24 healthy controls. Each subject performed time estimation and reproduction tasks using standardized affective pictures that were classified into 4 stimulus groups according to valence and level of arousal and presented for durations of 2, 4, and 6s. We analyzed temporal performance on these tasks using transformed data expressed as a proportion of the target period. RESULTS The interactions between arousal and valence were different in manic patients compared with euthymic patients and healthy controls in both time estimation and reproduction tasks. Manic patients showed no effect of positive valence low arousal stimuli in the time estimation task compared to euthymic patients and healthy controls. In the time reproduction task, the effect of emotional stimuli was reversed in manic patients compared to euthymic patients and healthy controls. Significant correlations between the severity of manic symptoms or illness severity and average temporal performance scores were found in manic patients. CONCLUSION Our results suggest that altered emotion-related time judgments may be a state-dependent phenomenon observed in manic patients only. This difference in time perception for emotional stimuli may be related to the underlying neurobiological mechanisms of the manic state.

P600 alteration of syntactic language processing in patients with bipolar mania: Comparison to schizophrenic patients and healthy subjects

BACKGROUND Disturbances in thought, speech, and linguistic processing are frequently observed in bipolar manic patients, but the underlying neurophysiological mechanisms are not well understood. P600 is a distinct, positive event-related potential component elicited by syntactic violations. Using the P600 ERP, we examined neural processing of syntactic language comprehension in patients with bipolar mania compared to patients with schizophrenia and healthy people. METHOD P600s were recorded from 21 manic patients with bipolar disorder, 26 patients with schizophrenia, and 29 healthy subjects during the presentation of 120 auditory sentences with syntactic violations or non-violations. Subjects were asked to judge whether each sentence was correct or incorrect. RESULTS Patients with mania and schizophrenia had significantly smaller P600 amplitudes associated with syntactic violations compared with healthy subjects. There was no difference in P600 amplitude between patient groups. For behavioral performance, patients with schizophrenia had significantly less accurate rates and longer reaction times compared with healthy subjects, whereas manic patients exhibited no significant differences in accuracy and only showed increased reaction times in comparison with healthy subjects. LIMITATIONS Psychotropic drug usage and small sample size. CONCLUSION Patients with bipolar mania have reduced P600 amplitude, comparable to patients with schizophrenia. Our findings may represent the first neurophysiological evidence of abnormal syntactic linguistic processing in bipolar mania.

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.

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.