Chang-Uk Lee

A nationwide survey on the prevalence of dementia and mild cognitive impairment in South Korea.

We investigated the prevalence of dementia and mild cognitive impairment (MCI) and the factors associate with risk of dementia from a representative nationwide sample of Korean elders. 8,199 randomly-sampled Koreans aged 65 years or older were invited to participate in the Phase I screening assessment using Mini-Mental State Examination by door-to-door home visit, and 6,141 subjects (response rate = 74.9%) responded. Among them, 2,336 subjects were invited to participate in the Phase II diagnostic assessment for dementia and MCI, and 1,673 subjects responded (response rate = 71.6%). Diagnostic assessments were administered using the Korean version of the Consortium to Establish a Registry for Alzheimers Disease Assessment Packet (CERAD-K) Clinical Assessment Battery. The CERAD-K Neuropsychological Assessment Battery was used for diagnosing MCI. Age-, gender-, education-, and urbanicity-standardized prevalence of dementia was estimated to be 8.1% (95% CI = 6.9-9.2) for overall dementia and 24.1% (95% CI = 21.0-27.2) for MCI. Alzheimers disease (AD) was the most prevalent type (5.7%) followed by vascular dementia (2.0%). Amnestic subtype (20.1%) was much more prevalent than nonamnestic subtype in MCI (4.0%). Older age, being male, lower education level, illiteracy, smoking, and histories of head trauma or depression were associated with increased dementia risk, and alcohol use and moderately intense exercise were associated with decreased dementia risk. We expect numbers of dementia patients to double every 20 years until 2050 in Korea and expect AD to account for progressively more dementia cases in the future.

Changes in the levels of plasma soluble fractalkine in patients with mild cognitive impairment and Alzheimer's disease.

Soluble fractalkine plays a distinctive role in the inflammatory processes of the nervous system; however, the role of soluble fractalkine in Alzheimers disease (AD) has not yet been investigated. In the present study, we evaluated the levels of plasma soluble fractalkine in patients with mild cognitive impairment (MCI), patients with AD and healthy controls. We also investigated the changes in the levels of plasma soluble fractalkine in patients with AD. A total of 102 patients with cognitive impairment, including 51 patients with MCI, 51 patients with AD, and 57 healthy control subjects, were enrolled in this study. The Mini-Mental Status Examination (MMSE) was used to evaluate the severity of cognitive impairment in patients with MCI and AD. The levels of plasma soluble fractalkine were measured using a specific enzyme-linked immunosorbent assay. There were significant group differences in the levels of plasma soluble fractalkine between the MCI, AD, and control groups. Post hoc analyses revealed significant differences between the MCI and control groups, the AD and control groups, and the MCI and AD groups. The level of plasma soluble fractalkine was significantly greater in the patients with mild to moderate AD than in the patients with severe AD. In addition, there was a positive correlation between MMSE score and plasma soluble fractalkine level in the patients with AD. This study provides preliminary evidence that soluble fractalkine is involved in the pathogenesis of AD.

A nationwide survey on the prevalence and risk factors of late life depression in South Korea

OBJECTIVE This study aimed to estimate prevalence rates and risk factors of LLD among a large nationwide sample of Korean elders in South Korea. METHOD Of 8199 randomly sampled Koreans aged 65 years or more, 6018 participated (response rate=73.4%). Using the Korean version of the short form Geriatric Depression Scale (SGDS-K), we classified individual scoring 8 or 9 as having possible depression and those scoring ≥ 10 as having probable depression. RESULTS The age-, gender-, education-, and urbanicity-standardized prevalences were 10.1% (95% CI=9.3-10.8) for possible depression, 17.8% (95% CI=16.8-8.7) for probable depression, and 27.8% (95% CI=26.7-29.0) for overall depression. Poverty, living alone, low education, illiteracy, smoking, history of head trauma, and low Mini Mental Status Examination score were associated with greater risk of depression, while mild alcohol use and moderate to heavy exercise were associated with lower risk of depression. However gender difference in the risk of depression was not found. CONCLUSION LLD is decidedly common in South Korea. It was associated with various sociodemographic and clinical factors, some of which are amendable through policy actions. This study was limited by use of the SGDS-K rather than a standardized clinical interview.

TPH Gene May Be Associated with Suicidal Behavior, but Not with Schizophrenia in the Korean Population

Tryptophan hydroxylase (TPH) is a rate-limiting enzyme in the biosynthesis of serotonin. This study was designed to examine whether A218C polymorphism, which has been identified in intron 7 of the TPH gene, may be associated with schizophrenia or the suicidal behavior of schizophrenics in the Korean population. TPH genotypes were determined in DNA samples from 217 schizophrenics and 236 healthy volunteers. Among the schizophrenic group, 27 patients had a history of suicidal behavior. Genomic DNA was amplified by a polymerase-chain-reaction-based method and restricted by NheI. A218C polymorphism was associated with a history of suicidal behavior in schizophrenics. This finding suggests that the TPH gene or a gene in its vicinity may influence suicidal behavior in schizophrenics. However, genotypic and allelic distrubutions of this polymorphism did not significantly differ between schizophrenics and controls.

Quinone oxidoreductase (NQO1) gene polymorphism (609C/T) may be associated with tardive dyskinesia, but not with the development of schizophrenia.

The association between the quinone oxidoreductase gene (NQO1) polymorphism (609C/T) and schizophrenia was examined to replicate and extend the findings of a previous study (Hori et al., 2003). The study sample was 107 schizophrenia in-patients and 106 healthy controls. The distributions of the NQO1 genotypes and alleles were not different between the schizophrenia patients and the controls. However, the frequency of the variant genotype was significantly higher in the subgroup with tardive dyskinesia (TD) than in the subgroup without (p=0.019). The subjects with allele T were significantly more frequent in the TD patients than in those without (odds ratio 2.256, 95% confidence interval 1.235-4.133). In addition, the Abnormal Involuntary Movement Scale (AIMS) score was significantly higher in the variant genotype group (T/T) than in other genotypic groups (C/C and C/T) (p=0.004). This study suggests that the NQO1 gene polymorphism (609C/T) may confer susceptibility to the development of TD in schizophrenia, at least in the Korean population.

Cerebral glucose metabolism in corticobasal degeneration comparison with progressive supranuclear palsy using statistical mapping analysis

This study measured the cerebral glucose metabolism in patients suffering from corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP). The aim was to determine if there is a different metabolic pattern using (18)F-labeled 2-deoxyglucose ((18)F-FDG) positron emission tomography (PET). The regional cerebral glucose metabolism was examined in 8 patients diagnosed clinically with CBD (mean age 69.6 +/- 7.8 years; male/female: 5/3), 8 patients with probable PSP (mean age 67.8 +/- 4.5 years; male/female: 4/4) and 22 healthy controls. The regional cerebral glucose metabolism between the three groups was compared using statistical parametric mapping (SPM) with a voxel-by-voxel approach (p < 0.001, 200-voxel level). Compared with the normal controls, asymmetry in the regional glucose metabolism was observed in the parietal, frontal and cingulate in the CBD patients. In the PSP patients, the glucose metabolism was lower in the orbitofrontal, middle frontal, cingulate, thalamus and mid-brain than their age matched normal controls. A comparison of the two patient groups demonstrated relative hypometabolism in the thalamus, the mid-brain in the PSP patients and the parietal lobe in CBD patients. These results suggest that when making a differential diagnosis of CBD and PSP, voxel-based analysis of the (18)F-FDG PET images using a SPM might be a useful tool in clinical examinations.

Cognitive emotion regulation strategies contributing to resilience in patients with depression and/or anxiety disorders

OBJECTIVE Research suggests that resilience is associated with favorable treatment outcome in patients with depression and/or anxiety disorders. In this regard, the identification of specific characteristics related to resilience that could provide targets for resilience-enhancement interventions is needed. Since the type of cognitive coping strategies is a possible marker of resilience, we investigated adaptive and maladaptive cognitive emotion regulation strategies contributing to resilience in patients with depression and/or anxiety disorders. METHODS A total of 230 outpatients with depression and anxiety disorders were consecutively recruited and completed the Cognitive Emotion Regulation Questionnaire, the Connor-Davidson Resilience Scale, the Beck Depression Inventory, and the State Anxiety Inventory. A linear regression model was used to determine which cognitive emotion regulation strategies predicted resilience after controlling for relevant covariates. Additionally, this model of resilience was compared with those of depression and anxiety symptoms. RESULTS Adaptive strategies were more strongly correlated with resilience than maladaptive strategies. In the regression model, more use of refocus on planning and positive reappraisal as well as less use of rumination predicted high resilience after controlling for age, gender, marital status, depression, and anxiety. Among these strategies, refocus on planning was the common strategy contributing to resilience and depression. CONCLUSION These results suggested that the cognitive emotion regulation strategies of refocus on planning, positive reappraisal, and less rumination contribute to resilience in patients with depression and anxiety disorders. It might provide potential targets for psychotherapeutic intervention to improve resilience in these patients.

Low trait anxiety, high resilience, and their interaction as possible predictors for treatment response in patients with depression.

BACKGROUND Although many demographic and clinical characteristics have been suggested to predict treatment outcome of depression, they provide only a weak prediction for clinical response. Based on the predictive values of trauma and biological markers involved in stress response, we investigated the roles of baseline trait anxiety and resilience, which were assumed as vulnerability and resilience factors, respectively, in predicting treatment response in naturalistically treated outpatients with depressive disorders. METHODS A total of 178 outpatients with depressive disorders were consecutively recruited and completed measures of trauma experiences, psychological symptoms, and resilience at baseline. Response was defined by Clinical Global Impression (CGI)-Improvement score ≤2 at last visit during a 6month-treatment period. Univariate analyses and multiple logistic regression analysis were performed to determine predictors of treatment response. RESULTS Among demographic and clinical variables, treatment response was associated with increased age, longer treatment duration, higher resilience, and lower trait anxiety. In logistic regression analysis, resilience, trait anxiety, and their interaction significantly predicted treatment response after adjusting for age and treatment duration. Interaction between resilience and trait anxiety remained significant in the final model. Examining the interaction between the two, patients with low trait anxiety were only significantly affected by the level of resilience in response rate. CONCLUSIONS Low trait anxiety, high resilience, and their interaction might contribute to better treatment response in depressed patients. Our result suggested that individual differences in responding to stress might be important in predicting treatment outcome of depression in addition to other demographic and clinical factors.

Glutathione S-transferase M1 polymorphism may contribute to schizophrenia in the Korean population.

The association between Glutathione S-Transferase M1 gene (GSTM1) polymorphism and schizophrenia was examined. One hundred and eleven in-patients with schizophrenia and 130 healthy controls were enrolled in this study. Genotyping was performed using a polymerase chain reaction-based method. The GSTM1 null genotype was significantly more frequent in the schizophrenia patients than in the controls (P=0.014, odds ratio=1.93, 95% confidence interval=1.115–3.351). On the other hand, the GSTM1 genotype variants were not associated with tardive dyskinesia or total abnormal involuntary movement scale scores. This study suggests that, at least in the Korean population, the GSTM1 polymorphism may confer susceptibility to the development of schizophrenia but not to tardive dyskinesia.

Characteristics associated with low resilience in patients with depression and/or anxiety disorders

PurposeDespite a growing body of research on resilience and its clinical significance in depression and anxiety disorders, relatively little is known about contributing factors for resilience in patients with these illnesses. We aimed to find characteristics of patients having low resilience for elucidating its clinical implications in depression and/or anxiety disorders, primarily focused on potentially modifiable variables.MethodsA total of 121 outpatients diagnosed with depression and/or anxiety disorders completed questionnaires measuring socio-demographic, clinical, and positive psychological factors. We divided patients into the three groups based on their Connor–Davidson resilience scale scores and investigated predictors of the low- and medium- versus high-resilience groups using multinomial logistic regression analysis.ResultsIn the final regression model, low spirituality was revealed as a leading predictor of lower-resilience groups. Additionally, low purpose in life and less frequent exercise were associated with the low- and medium-resilience groups, respectively. Severe trait anxiety characterized the low- and medium-resilience groups, although it was not included in the final model.ConclusionsSpirituality, purpose in life, and trait anxiety contribute to different levels of resilience in patients with depression and/or anxiety disorders. Our results would deepen the understanding of resilience and provide potential targets of resilience-focused intervention in these patients.