Jae Seung Chang

Differential pattern of heart rate variability in patients with schizophrenia.

The cardiac autonomic dysfunction has been reported in patients with schizophrenia. Heart rate variability (HRV) provides non-invasive indices of cardiac autonomic modulation. This study examined whether patients with schizophrenia may show a distinctive pattern of HRV compared to healthy controls. Nine measures of time, frequency and complexity domains were extracted from 5-min resting evaluation of HRV in 30 unmedicated patients with schizophrenia and 30 age- and gender-matched controls. In addition to inferential statistics, a hierarchical clustering (HC) was used to examine difference in the interrelationships among HRV measures between the two groups. Multivariate analysis of variance revealed a significant group effect. Significantly lower sample entropy (SampEn) and a trend towards a higher ratio of low- to high frequency (LF/HF) were observed in the schizophrenia group. In the results of HC using Wards method, SampEn co-clustered with LF/HF ratio in patients with schizophrenia compared to the separation of LF/HF ratio in healthy controls. In concert with decreased parasympathetic activity, low complexity of heart rate dynamics may reduce adaptability of cardiovascular system to changes in internal or external environment, thus increasing the risk of cardiovascular events. Diverse HRV measures combined in a multivariate fashion appear to be useful in understanding the pattern of neurocardiac modulation in patients with schizophrenia.

Similarities and differences of white matter connectivity and water diffusivity in bipolar I and II disorder

Differences and similarities in microstructural white matter alterations between bipolar I and bipolar II disorder were investigated. Twelve patients with bipolar I disorder, 12 patients with bipolar II disorder and 22 healthy controls underwent diffusion tensor imaging. Fractional anisotropy (FA) and mean apparent diffusion coefficient (ADC) maps were compared between groups using voxel-based whole brain analyses. Both bipolar I and II groups had a FA decrease in the corpus callosum, cingulate and right prefrontal regions, and a ADC increase in the medial frontal, anterior cingulate, insular and temporal regions, compared to controls. The bipolar I group had a FA decrease in the right temporal white matter and a ADC increase in the frontal, temporal, parietal and thalamic regions, compared to the bipolar II group. The results suggest disrupted integrity of commissural fibers and white matter in the anterior paralimbic structures in bipolar disorder. Relative sparing of the dorsal system and long association fibers may differentiate bipolar II from I disorder.

Changes in heart rate dynamics of patients with schizophrenia treated with risperidone.

Neurocardiac dysregulation has been reported in schizophrenia. Indices of heart rate variability (HRV) are useful in assessing the status of cardiac autonomic regulation. We explored within-subject changes in HRV indices in acutely ill patients with schizophrenia treated with risperidone. Sixteen medication-naïve or medication-free patients with DSM-IV schizophrenia completed electrocardiogram (ECG) assessments at baseline and after six weeks of treatment with risperidone. Indices of HRV were extracted from 5-min resting ECG recordings and compared to those obtained from control subjects matched for age and gender. Psychiatric and drug-induced extrapyramidal symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS) and the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). In comparison with matched controls, patients with acute schizophrenia showed lower values of time-domain measures, lower high-frequency power (HF) and a higher ratio of low to high frequency (LF/HF). In the within-subject analyses, a significant decrease in LF/HF was associated with risperidone treatment. In addition, LF/HF, which initially co-clustered with clinical variables, congregated with other HRV measures after the six-week risperidone treatment. These results indicate that, in the therapeutic process, risperidone treatment may exert a beneficial influence on the sympathovagal imbalance in acute schizophrenia.

Illiteracy and the incidence of Alzheimer's disease in the Yonchon County survey, Korea

BACKGROUND This study aims to establish the incidence rates of Alzheimers disease (AD) and to understand the relations between illiteracy and AD in the Korean Yonchon survey cohort. METHODS A community-based, dementia-free cohort of 966 people aged 65 years and older was followed up for an average of 5.4 +/- 1.60 years to detect incident AD cases using a two-phase procedure. Age-specific incidence rates were calculated using a person-years approach with Poisson distribution confidence intervals. Data were analyzed using the Cox proportional hazards model to find the hazard ratio of illiteracy. RESULTS The participating percentage of the survivors was 86.4% and 74 subjects were diagnosed with AD. Incidence rates per 1000 person-years were 20.99 (95% CI 16.48 to 26.35) for AD. The hazard ratio of illiteracy was 1.78 (95% CI 1.08 to 2.93) adjusted for age, sex, educational level. AD developed more rapidly with aging in the illiterate group than in the literate group. CONCLUSIONS Illiteracy is associated with a higher risk of AD and the risk increases with age.

Patients taking medications for bipolar disorder are more prone to metabolic syndrome than Korea's general population

Despite growing concerns about the co-morbidity of metabolic syndrome (MetS) and bipolar disorder, few studies have been conducted on this topic in Asian populations. This study examined Korean patients with bipolar disorder to assess its co-morbidity with MetS and to compare the prevalence of MetS in patients with medication for bipolar disorder with that of healthy patients. We used cross-sectional data from the medical records of patients with bipolar disorder who presented to the psychiatric clinic in Seoul National University Hospital between June 2007 and June 2008. The control group, matched for age and gender, was randomly drawn from visitors to the Health Promotion Center at the same hospital during the same period. We compared the prevalence of MetS between these two groups with independent sample t-tests and chi-squared tests. We also calculated the indirectly standardized prevalence ratio (ISPR) with a standardization that used the Fourth Korean National Health and Nutrition Examination Survey (KNHNES, 2007). The prevalence of MetS in patients who took medication for bipolar disorder (N=152) was 27.0%, 25.0% and 25.7%, based on the definitions of the American Heart Association and the National Heart, Lung and Blood Institutes adaptation of the Adult Treatment Panel III (AHA), the National Cholesterol Education Program for Adult Treatment Panel III (ATPIII) and the International Diabetes Federation (IDF), respectively. The present study determined that the prevalence of MetS was significantly higher in patients with bipolar disorder than in the control group; the odds ratios (OR) (95% CI) were 2.44 (1.35-4.40), 2.48 (1.34-4.59) and 2.57 (1.40-4.74), based on the definition of the AHA, ATPIII and IDF, respectively. The ISPR (95% CI) was 1.48 (1.02-1.93), 1.54 (1.05-2.03) and 1.98 (1.36-2.60), respectively. Patients with medications for bipolar disorder showed a significantly higher prevalence of increased waist circumference, elevated triglycerides, and reduced HDL-cholesterol than the control group. The prevalence of MetS in patients taking medication for bipolar disorder was higher than that in the general population. Obesity and dyslipidemia were particularly prevalent in patients with bipolar disorder.

Differential pattern of semantic memory organization between bipolar I and II disorders

Semantic cognition is one of the key factors in psychosocial functioning. The aim of this study was to explore the differences in pattern of semantic memory organization between euthymic patients with bipolar I and II disorders using the category fluency task. Study participants included 23 euthymic subjects with bipolar I disorder, 23 matched euthymic subjects with bipolar II disorder and 23 matched control subjects. All participants were assessed for verbal learning, recall, learning strategies, and fluency. The combined methods of hierarchical clustering and multidimensional scaling were used to compare the pattern of semantic memory organization among the three groups. Quantitative measures of verbal learning, recall, learning strategies, and fluency did not differ between the three groups. A two-cluster structure of semantic memory organization was identified for the three groups. Semantic structure was more disorganized in the bipolar I disorder group compared to the bipolar II disorder. In addition, patients with bipolar II disorder used less elaborate strategies of semantic memory organization than those of controls. Compared to healthy controls, strategies for categorization in semantic memory appear to be less knowledge-based in patients with bipolar disorders. A differential pattern of semantic memory organization between bipolar I and II disorders indicates a higher risk of cognitive abnormalities in patients with bipolar I disorder compared to patients with bipolar II disorder. Exploring qualitative nature of neuropsychological domains may provide an explanatory insight into the characteristic behaviors of patients with bipolar disorders.

An integrative assessment of the psychophysiologic alterations in young women with recurrent major depressive disorder.

Objective Alterations in neuroelectrical activities coincide with major depressive disorder (MDD). This study examines the pattern of cerebral activity and cardiac autonomic parameters of euthymic women with recurrent MDD. Methods Resting electroencephalograms and electrocardiograms were recorded from 20 women with MDD receiving escitalopram and 40 matched and healthy women. We computed frontal alpha asymmetry to evaluate the interhemispheric balance. Parameters of heart rate variability were extracted to assess cardiac autonomic control. Sample entropy was used to assess the complexity of neurocardiac dynamics. The relationship between cardiovagal activity and alpha electroencephalogram was examined with a coherence analysis. Results Multivariable analysis of variance revealed a differential pattern of psychophysiologic variables between MDD patients and controls (p = .03). MDD was associated with a tendency toward lower left frontal activity (−0.06 [standard deviation = 0.14] versus 0.04 [0.17] ln&mgr;V2, p = .04). Discriminant analysis demonstrated more right frontal activation, a lower high-frequency heart rate power spectrum, and a higher ratio of the low- to high-frequency heart rate power spectrum in patients with MDD compared with controls. Residual depressive symptoms (r = −0.09 to 0.11, p = .63–.99) and escitalopram dosage (r = −0.09 to 0.28, p = .22–.84) were not correlated with autonomic measures. Coherence between normalized high-frequency component of the heart rate power spectrum and alpha power was not significant (F3, p = .27; F4, p = .16). Conclusions Euthymic women with recurrent MDD have a distinctive psychophysiologic profile. This profile may reflect altered frontal activation and a reduced cardiovagal tone in depression. Abbreviations MDD = major depressive disorder EEG = electroencephalogram HRV = heart rate variability ECG = electrocardiogram HDRS = Hamilton Depression Rating Scale SSRI = selective serotonin reuptake inhibitor EOG = electrooculogram RR = beat to beat NN = normal to normal LF = low-frequency component of the heart rate power spectrum HF = high-frequency component of the heart rate power spectrum SampEn = sample entropy MANCOVA = multivariate analysis of covariance

The usefulness of a self-report questionnaire measuring auditory verbal hallucinations.

A self-report measure of psychotic symptoms has been considered to be unsuitable due to the possible denial of symptoms in the patients with schizophrenia. However, a self-report questionnaire would be an efficient tool for the evaluation of subjective aspects of auditory verbal hallucination (AVH), which requires further clarification. In this study, a total of 87 patients with schizophrenia took baseline evaluations for Hamilton Program for Schizophrenia Voices Questionnaire (HPSVQ), a self-report questionnaire for AVH, and Psychotic Symptom Rating Scales-Auditory Hallucination Subscale (PSYRATS-AH) and an item measuring hallucinations (P3) on Positive and Negative Syndrome Scale for Schizophrenia (PANSS), both interviewer-rated scales for AVH. At 1 week and at 6 months post-baseline, 39 and 68 patients repeated HPSVQ and PSYRATS-AH, respectively. Total scores on HPSVQ showed good agreement with those on PSYRATS-AH and PANSS, Item P3, and HPSVQ showed good test-retest reliability and internal consistency. In addition, the changes in total scores of HPSVQ during 6-month follow-up were also highly correlated to those of PSYRATS-AH. The findings of factor analysis and hierarchical cluster analysis suggested that the items addressing emotional characteristics of AVH constituted one factor and that the remaining items, primarily concerning the physical characteristics, combined to form another factor. Taken together, the HPSVQ, a self-report questionnaire measuring AVH, was characterized by good psychometric properties, which suggests the appropriateness of a self-report scale for examining the internal structure of AVH in patients with schizophrenia.

Reasons for desiring death: Examining causative factors of suicide attempters treated in emergency rooms in Korea

BACKGROUND Suicide attempters treated in emergency rooms were studied in order to understand the motives behind this behavior. Disparities between the etiological contributions to suicidal ideation, intention, and action were examined in order to characterize motives in these categories. METHODS Suicide attempters who visited the emergency departments of seven university hospitals were analyzed. Attempts leading to mortality were excluded from the analysis. Participants were assessed using semi-structured questionnaires, the results of which were noted on their medical records. These were analyzed retrospectively. RESULTS Attempter self-report assessment revealed that participants chose external sources of stress (75.4%) and psychiatric symptoms (19.1%) as their main reasons for attempting suicide. However, assessments by interviewers indicated that stressors contributed to suicide attempts to a lesser degree (52.8%) while psychiatric symptoms were more etiologically relevant (36.6%). Compared to those with stressors that was identified as causal in both self-report and clinician assessed evaluation, the participants-regardless of their self-report evaluation-who identified with causal psychiatric symptoms by psychiatrist had more severe and intense suicidal ideation and more determined suicidal intention. LIMITATIONS We collected samples from only university hospitals, resulting in selection bias. In addition, we did not use psychiatric scales to evaluate the participants׳ symptoms. CONCLUSIONS Stress was the greatest motive for attempting suicide, affirmed in both self-report and clinician assessed evaluation. A fair proportion of people were objectively identified as being motivated by psychiatric symptoms, yet were unaware of what they suffered from. Furthermore, suicide severity, intensity, and suicidal intention were stronger in psychiatrically driven cases.

Reduction in hospital stay of chronic schizophrenic patients after long-term clozapine treatment.

The present study aimed to elucidate the effectiveness of clozapine treatment in reducing the disabling period of chronically ill schizophrenic patients by investigating their rehospitalization status. Of 232 schizophrenic patients with a history of clozapine use who were recruited from the clinic at Seoul National University Hospital, 117 were selected who had been followed up for more than 1 year with respect to rehospitalization. To obtain information about the period before the clozapine change, a chart review of these 117 patients was conducted. The number and length of hospitalizations of the patients significantly decreased after clozapine treatment compared to the same period before clozapine treatment. The hospital days per year of the patients were also decreased significantly after clozapine introduction. By analysing 38 patients who were followed up for more than 5 years, it was suggested that the decrease in the number and length of hospitalizations was substantially sustained for up to 5 years after clozapine treatment. This study showed that the number and length of hospitalizations are significantly decreased by long-term clozapine treatment and that this effect can positively affect the social outcome of schizophrenic patients.