In-Won Chung

Lifetime and 12-month prevalence of DSM-IV psychiatric disorders among Korean adults.

The objective was to estimate the prevalence and correlates of psychiatric disorders in a nationwide sample of Korean adults. Face-to-face interviews were conducted with the Korean version of Composite International Diagnostic Interview 2.1/DSM-IV (N = 6275, response rate 79.8%). The lifetime and 12-month prevalences for all types of DSM-IV disorders were 33.5% and 20.6%, respectively. Those of specific disorders were as follows: 17.2% and 7.1% for alcohol use disorder, 11.2% and 7.4% for nicotine use disorder, 5.2% and 4.2% for specific phobia, 4.3% and 1.7% for major depressive disorder, and 2.3% and 1.0% for generalized anxiety disorder. Among the sociodemographic variables, widowed status, higher income, and rural residence were the risk factors for both lifetime major depressive disorder and alcohol use disorder after controlling for gender, age, and education. The prevalence of psychiatric disorders was higher than those observed in other East-Asian countries and most European countries, but lower than that in the United States. Alcohol use disorder was particularly high in Korea.

Relationships of sleep duration with sociodemographic and health-related factors, psychiatric disorders and sleep disturbances in a community sample of Korean adults

The aim of this study is to examine relationships of sleep duration with sociodemographic and health‐related factors, psychiatric disorders and sleep disturbances in a nationwide sample in Korea. A total of 6510 subjects aged 18–64 years participated in this study. Logistic regression was used to calculate the odd ratios and 95% confidence intervals of the covariates, psychiatric disorders and sleep disturbances across the following sleep duration categories: 5 h or less, 6, 7, 8 and 9 h or more per day. Low levels of education, unemployment and physical illness were associated with sleeping for 5 h or less and 9 h or more. Being older and widowed/divorced/separated, high levels of physical activity, pain/discomfort, obesity and high scores on the General Health Questionnaires were associated with sleeping for 5 h or less. Female, being younger and underweight were associated with sleeping for 9 h or more. Alcohol dependence, anxiety disorder and social phobia were associated significantly with sleeping for 5 h or less and 9 h or more. Other psychiatric disorders were more common in subjects who slept for 5 h or less (e.g. alcohol use disorder, mood disorder, major depressive disorder, dysthymic disorder, obsessive‐compulsive disorder and specific phobia) or 9 h or more (e.g. post‐traumatic stress disorder). In addition, subjects who slept for 5 h or less reported more sleep disturbances than did subjects who slept for 7 h. Short or long sleep is associated with psychiatric disorders and/or sleep disturbance, therefore attention to the mental health of short or long sleepers is needed.

Prevalence and Correlates of DSM-IV Mental Disorders in South Korean Adults: The Korean Epidemiologic Catchment Area Study 2011

Objective The aim of this study was to estimate the prevalence and correlates of mental disorders in Korean adults. Methods Door to door household surveys were conducted with community residents aged 18-74 years from July 19, 2011, to November 16, 2011 (n=6,022, response rate 78.7%). The sample was drawn from 12 catchment areas using a multistage cluster method. Each subject was assessed using the Korean version of the World Health Organization Composite International Diagnostic Interview (CIDI) based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Results Lifetime and 12-month prevalence estimates were as follows: alcohol use disorders, 13.4% and 4.4%, respectively; nicotine use disorders, 7.2% and 4.0%, respectively; anxiety disorders, 8.7% and 6.8%, respectively; and mood disorders, 7.5% and 3.6%, respectively. The prevalence rates of all types of DSM-IV mental disorders were 27.6% and 16.0%, respectively. Being female; young; divorced, separated, or widowed; and in a low-income group were associated with mood and anxiety disorders after adjustment for various demographic variables, whereas being male and young were associated with alcohol use disorders. Higher income was not correlated with alcohol use disorder as it had been in the 2001 survey. Conclusion The rate of depressive disorders has increased since 2001 (the first national survey), whereas that of anxiety disorders has been relatively stable. The prevalence of nicotine and alcohol use disorders has decreased, and the male-to-female ratio of those with this diagnosis has also decreased.

Gender-specific association of the brain-derived neurotrophic factor gene with attention-deficit/hyperactivity disorder.

Objective Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder with a strong genetic component. Brain-derived neurotrophic factor (BDNF), which participates in the differentiation and survival of dopaminergic and noradrenergic neurons, could play a role in ADHD development. We aimed to explore the relationships between ADHD and BDNF gene polymorphism. Methods We conducted a case-control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test on 151 trios, and compared the results of a continuous performance test (CPT) according to the genotype of the three single nucleotide polymorphisms (rs11030101, rs6265, rs16917204) in the BDNF gene. Results In the case-control analysis, the AA genotype of the BDNF rs11030101 polymorphism was significantly associated with ADHD only in girls (p=0.024, odds ratio=3.00). The T-G-G haplotype was significantly less frequent (p=0.005) and A-G-G was more frequent (p=0.048) in girls with ADHD than in control girls (global p=0.027). A multivariate analysis of variance for commission errors on the CPT showed a significant main effect for the rs11030101 genotype (p=0.026) and an interaction effect of the rs11030101 genotype and gender (p=0.032) in ADHD probands. Conclusion These results provide preliminary evidence for a gender-specific association between BDNF and ADHD in the Korean population.

Neurotrophin-3 gene, intelligence, and selective attention deficit in a Korean sample with attention-deficit/hyperactivity disorder

OBJECTIVE Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder with a strong genetic component. Neurotrophin-3 (NTF3), which participates in the differentiation and survival of dopaminergic and noradrenergic neurons, has been identified as a factor in the development of ADHD. We investigated the relationships between ADHD and NTF3 gene polymorphism. METHODS We conducted a case-control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test (TDT) on 151 trios, and compared the intelligence quotient (IQ) and a continuous performance test (CPT) according to the genotype of two single-nucleotide polymorphisms (SNPs) (rs6332 and rs6489630) in the NTF3 gene. RESULTS In the case-control and family-based analyses, NTF3 was not significantly associated with ADHD. However, in the ADHD probands, the subjects with AA genotype in the rs6332 SNP had significantly higher mean T-scores for commission errors on the CPT than did those with the AG genotypes (p=0.045). The mean IQ of the ADHD probands who had the CC genotype of the rs6489630 SNP were higher compared with those who had the CT or TT genotype (p=0.035). The mean T-score for response time on the CPT was higher in the subjects with TT genotype in the rs6489630 SNP compared to those with the CC or CT genotype, even after adjusting for the effect of IQ (p=0.021). CONCLUSIONS These results provide preliminary evidence of an association between NTF3 and the intelligence and selective attention deficit in the Korean population.

Changes in neurocognitive function in patients with schizophrenia after starting or switching to amisulpride in comparison with the normal controls.

Abstract We examined short- and long-term changes in neurocognitive functions in patients with schizophrenia who were either started or switched to amisulpride in comparison with the normal controls. Fifty-seven patients treated with amisulpride and 60 normal controls completed a comprehensive neurocognitive function test battery at the baseline, the 8-week, and the 1-year follow-up. We conducted and compared the results of both intention-to-treat (ITT) and per-protocol (PP) analyses to account for the follow-up loss. Three general results obtained were as follows: (1) the degree of the improvements in neurocognitive function was comparable to those of other second-generation antipsychotics in both ITT and PP analysis; (2) in light of the relative effect size, the composite effect size and the effect size in most measures in both ITT and PP analyses were smaller for the patient group than those of the control group, signifying that improvement in performance may be largely attributable to practice effects; and (3) nonetheless, there were evidences of both short- and long-term improvements in some cognitive tasks, such as in the Korean-Wechsler Adult Intelligence Scale vocabulary subtest and the Trail Making Test, that may not be accounted by practice effect. These results suggest the need to include a healthy control group to validate the medication effect of cognitive improvements in patients with schizophrenia and to consider practice effect in interpreting the results of repeated administration of neurocognitive function tests.

Clozapine induces chloride channel-4 expression through PKA activation and modulates CDK5 expression in SH-SY5Y and U87 cells

OBJECTIVES Second-generation antipsychotic drugs, such as clozapine, were reported to enhance neurite outgrowth by nerve growth factor in PC12 cells. The authors previously showed that chloride channel 4 (CLC-4) is responsible for nerve growth factor-induced neurite outgrowth in neuronal cells. In this study, we examined whether clozapine induces CLC-4 in neuroblastoma and glioma cells. METHODS The effect of clozapine on CLC-4 expression was examined in neuroblastoma (SH-SY5Y) and glioma (U87) cells. To investigate the signaling pathway responsible for clozapine-induced CLC-4 expression, the phosphorylation of cAMP response element-binding protein (CREB), which binds CRE in the promoter of the human CLC-4 gene, was examined. To identify the target of clozapine induced CLC-4, CLC-4 siRNA was introduced to neuroblastoma and glioma cells for functional knockdown. RESULTS We observed that clozapine increased CLC-4 expression in both SH-SY5Y and U87 cells. Clozapine induced CREB phosphorylation, but in the presence of inhibitor of protein kinase A (an upstream kinase of CREB) clozapine-induced CLC-4 expression was suppressed. Finally, we found that CLC-4 knockdown suppressed clozapine-induced cyclin-dependent kinase 5 (CDK5) expression in SH-SY5Y and U-87 cells suggesting CDK5 as potential molecular target of clozapine induced CLC-4 expression. CONCLUSIONS The results of the present study suggest that clozapines therapeutic effect may include the induction of CLC-4 which is dependent on CREB activation via PKA. We also found that functional knockdown of CLC-4 resulted in reduction of CDK5 expression, which may also be implicated in clozapines therapeutic effect.

The acute and long-term effectiveness of amisulpride in patients with schizophrenia: results of a 12-month open-label prospective follow-up study

To compare the effectiveness of amisulpride in acute (up to 8 weeks) and maintenance (week 8 to 12 months) phases of a 12‐month course of treatment in a heterogeneous group of patients with schizophrenia.

Differences in the internal structure of hallucinatory experiences between clinical and nonclinical populations

We investigated differential patterns of hallucinatory experiences between nonclinical and clinical samples. A total of 223 nonclinical individuals (108 females) and 111 subjects with schizophrenia (54 females) completed the Launay-Slade Hallucination Scale-Revised (LSHS-R) and Perceptual Aberration Scale (PAS). The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was used for the nonclinical group, and the Positive and Negative Syndrome Scale (PANSS) hallucination item was used for the clinical group. Cronbachs alpha values showed good internal consistency for the LSHS-R. In the two groups, significant associations were found between LSHS-R and PAS scores. Two factors were extracted through a principal component analysis (PCA) in the nonclinical group, and three factors were identified in the clinical group. The results of a hierarchical cluster analysis (HCA) revealed that a perception-cognition dimension was clear cluster discriminating element for the nonclinical group, whereas alterations in perception-cognition dimension were characteristic in cluster structure of the clinical group. Our findings suggest that the nature of hallucinatory experiences may differ qualitatively between a nonclinical population and subjects with schizophrenia. Perceptual or cognitive aberrations may add a psychopathologic dimension to hallucinatory experiences. Exploring the internal structure of hallucinatory experiences may provide explanatory insight into these experiences in the general population.

Comparison of clinician-rated and self-report insight in Korean patients with schizophrenia using VAGUS insight scale

This study was aimed to explore self-report auditory verbal hallucinations to provide unique and valuable information in addition to clinician-rated assessment in patients with schizophrenia. The VAGUS (http://www.vagusonline.com) is a recently developed insight scale that includes both clinician-rated (CR) and self-report (SR) versions. Insight measures obtained by the two versions of the VAGUS from the clinicians and the patients, respectively, in forty-one patients diagnosed with schizophrenia by DSM-IV-TR criteria were compared. Correlation coefficients for inter-scale convergence and 3-D biplots for multivariate relationship were derived from the subscales of the VAGUS. For external validation, correlation analyses with abridged version of Scale to Assess Unawareness in Mental Disorder (SUMD-A) and PANSS G12 item were conducted. Total scores of VAGUS-CR and -SR were 5.2 ± 2.6 and 4.9 ± 2.2, respectively. There was a strong correlation between them along with moderate pairwise correlations among the subscales. The 3-D biplots demonstrated that most subscales were clustered as a single factor apart from self-report Symptom Attribution separated as an independent factor. The VAGUS-CR, not -SR correlated significantly with the SUMD-A and PANSS G12. The utility of the VAGUS in reaching more overall understanding of the elusive phenomenon of insight in patients with schizophrenia is discussed.