Sang-Keun Chung

Reliability and validity of the Korean version of the Impact of Event Scale-Revised

OBJECTIVES The aim of this study was to explore the reliability and validity of the Impact of Event Scale-Revised Korean version (IES-R-K), a self-report scale for assessment of posttraumatic stress disorder (PTSD). METHODS The original Impact of Event Scale-Revised was translated into Korean, and the comparability of content was verified through back-translation procedures. This multicenter study included 93 patients with PTSD, 73 nonpsychotic psychiatric patients, and 88 healthy controls drawn from 18 hospitals across the country. The subjects were assessed using IES-R-K, Clinician-Administered PTSD Scale (CAPS), Beck Depression Inventory, and State Trait Anxiety Inventory (STAI; state anxiety subscale [STAI-S], trait anxiety subscale [STAI-T]) scales. RESULTS In the reliability test, Cronbach alpha coefficient and test-retest reliability were .93 and 0.91, respectively, indicating that the IES-R-K has good internal consistency. One-way analysis of variance revealed significant differences in IES-R-K scores among the patients with PTSD, nonpsychotic psychiatric patients, and healthy controls (F = 139.1, P < .001). Duncan post hoc test showed the significant differences among the 3 groups. To assess the validity of the IES-R-K, correlation coefficient between the IES-R-K and CAPS, STAI-S, and STAI-T was calculated. We found that there was a relatively high degree of correlation between the IES-R-K and CAPS (r = 0.92, P < .001). However, there was a relatively less degree of correlation between STAI-S and STAI-T and IES-R-K (r = 0.30, P < .001). Taken these together, IES-R-K showed good discriminant validity. CONCLUSION The IES-R-K showed good reliability and validity for the assessment of PTSD symptom severity. The IES-R-K is a useful instrument for assessing PTSD symptoms in Korea.

Aripiprazole plus divalproex for recently manic or mixed patients with bipolar I disorder: a 6-month, randomized, placebo-controlled, double-blind maintenance trial.

The goal of this study was to investigate the safety and efficacy in preventing relapse of a mood episode in recently manic or mixed episode patients with bipolar I disorder stabilized with aripiprazole and divalproex combination.

Effect of barrier growth temperature on morphological evolution of green InGaN/GaN multi-quantum well heterostructures

Surface morphology of green InGaN/GaN multi-quantum wells (MQWs) on a sapphire substrate with various high temperature grown GaN barriers has been evaluated. Keeping the InGaN well growth temperature constant at 740 °C, a series of MQWs were grown with GaN barrier temperatures varied up to 910 °C. GaN barriers grown below 800 °C lead to the generation of a high density of V-defects and inclusions embedded within V-defects as observed by atomic force microscopy. Scanning electron microscopy and cathodoluminescence (CL) studies revealed that the embedded inclusions are of two kinds: one of them appears as bright spots in CL mapping while the other appears as the surrounding region. Temperature ramping and subsequent interruption for GaN barrier growth suppresses both kinds of inclusion defects and also significantly reduces the V-defect density. An inclusion-free smooth surface is obtained for green emitting InGaN/GaN MQWs with the GaN barrier grown at 910 °C.

Topiramate and divalproex in combination with risperidone for acute mania: a randomized open-label study

Mood stabilizers and atypical antipsychotics are commonly combined for the treatment of bipolar mania. The aim of this study was to compare the effectiveness and tolerability of topiramate and divalproex in combination with risperidone for treating acute mania patients in a naturalistic treatment setting. Seventy-four patients who met the DSM-IV criteria for bipolar mania were enrolled in this study. In order to assess the efficacy and the extrapyramidal symptoms (EPS), the Young Mania Rating Scale (YMRS), Clinical Global Impression (CGI) and Simpson-Angus Rating Scale (SARS) were measured at the baseline and at weeks 1, 3 and 6. From the baseline to the endpoint, the YMRS and CGI scores were reduced by 67.9% and 56.6% in the topiramate plus risperidone group (TPMG). The YMRS and CGI scores were also reduced by 63.7% and 58.2% in the divalproex plus risperidone group (DVPG). The weight and body mass index (BMI) increased significantly by 3.6% and 3.3% from the baseline to the endpoint in the DVPG, while they decreased by 0.5% and 0.4%, respectively, with no significant difference in the TPMG. There were no serious adverse events in either group. Despite the methodological limitations, topiramate was effective and tolerable for treating acute mania and may also be a promising alternative to a weight-gain liable mood stabilizer (MS) such as divalproex.

Reliability and validity of the Korean version of the Davidson Trauma Scale

The Davidson Trauma Scale (DTS) is a validated, 17-item, brief global assessment scale for posttraumatic stress disorder (PTSD). The purposes of this study were to develop a Korean version of the DTS (DTS-K) while maintaining its basic structure and to evaluate its reliability and validity for the Korean population. Participants of this study included 93 patients with PTSD (PTSD group), 73 patients with nonpsychotic mood or other anxiety disorders (psychiatric control group), and 88 healthy controls (normal control group). Subjects completed psychometric assessments, including the DTS-K and the Korean version of the Clinician-Administered PTSD Scale and the State Trait Anxiety Inventory. The DTS-K showed good internal consistency (Cronbach alpha = .97) and test-retest reliability (r = .93). The DTS-K showed a significantly positive correlation with Clinician-Administered PTSD Scale (r = .94). The highest diagnostic efficiency of DTS-K was at a total score of 47, with sensitivity and specificity of 0.87 and 0.84, respectively. Our findings suggest that the DTS-K is composed of good psychometric properties and is a valid and reliable tool for assessing the frequency and severity of PTSD symptoms regardless of ethnicity.

Factors associated with depression among elderly Koreans: the role of chronic illness, subjective health status, and cognitive impairment

The objective of this cross‐sectional study was to investigate the relationship between depression in elderly individuals and chronic illness, subjective health status, and cognitive impairment.

Rash in adult patients receiving lamotrigine to treat bipolar I disorder in Korea: a multicenter, prospective, naturalistic, open-label trial.

The goal of this study was to assess the incidence of rash occurring in patients received lamotrigine to treat bipolar I disorder in a real world setting in Korea. We included a heterogeneous sample with multiple medications and medical comorbidities. Lamotrigine was added to the current therapy regime for DSM-IV bipolar I patients on an open-label basis for 12 weeks. The incidences of rash and other adverse events were assessed. The primary outcome measure was the incidence of rash. A total of 237 adult patients were included in the present study and 173 patients (73.0%) completed the 12 weeks of treatment. Thirty patients (12.7%) developed a rash, of whom 2 (0.8%) developed a serious rash. There were no patients who developed Stevens-Johnson syndrome or toxic epidermal necrolysis. The median time of rash onset was 16 days. As a group, patients who did not experience rash were significantly heavier than those who did. Our findings suggest that the incidence of serious rash associated with lamotrigine is low. The prescription of lamotrigine should be undertaken with appropriate consideration of the potential risk of adverse events including rash to the patient in relation to potential benefit from improvement of bipolar disorder.

Open‐label, dose‐titration tolerability study of atomoxetine hydrochloride in Korean, Chinese, and Taiwanese adults with attention‐deficit/hyperactivity disorder

The primary objective of this study was to assess the overall safety and tolerability of atomoxetine in Korean, Chinese, and Taiwanese adults with attention‐deficit/hyperactivity disorder (ADHD).

Long-term Escitalopram Treatment in Korean Patients with Panic Disorder: A Prospective, Naturalistic, Open-label, Multicenter Trial

Objective Panic disorder is characterized by recurrent panic attacks, persistent concerns about additional attacks, and worry about the implications of the attack or significant changes in behavior related to the attacks. We examined the efficacy of 24-week naturalistic, open-label escitalopram treatment in terms of the response and remission rates and functional disability in 119 adult Korean patients with panic disorder from 6 clinical centers in South Korea. Methods Clinical severity and functional impairment were assessed at baseline and at 4, 12, and 24 weeks after the treatment using the Panic Disorder Severity Scale and Sheehan Disability Scale. Ninety-six patients (80.7%) showed a treatment response, and 87 patients (73.1%) had attained remission after 24 weeks of escitalopram treatment. Results Continuous improvement in the Panic Disorder Severity Scale and Sheehan Disability Scale scores was found over the 24 weeks of treatment. Conclusion These findings suggest that escitalopram treatment is very effective for panic disorder in terms of both response and remission rates and that long-term pharmacotherapy with escitalopram continuously improved panic symptoms and functional disability in Korean patients with panic disorder.

Characteristics of Mg-doped and In–Mg co-doped p-type GaN epitaxial layers grown by metal organic chemical vapour deposition

Mg-doped and In?Mg co-doped p-type GaN epilayers were grown using the metal organic chemical vapour deposition technique. The effect of In co-doping on the physical properties of p-GaN layer was examined by high resolution x-ray diffraction (HRXRD), transmission electron microscopy (TEM), Hall effect, photoluminescence (PL) and persistent photoconductivity (PPC) at room temperature. An improved crystalline quality and a reduction in threading dislocation density are evidenced upon In doping in p-GaN from HRXRD and TEM images. Hole conductivity, mobility and carrier density also significantly improved by In co-doping. PL studies of the In?Mg co-doped sample revealed that the peak position is blue shifted to 3.2?eV from 2.95?eV of conventional p-GaN and the PL intensity is increased by about 25%. In addition, In co-doping significantly reduced the PPC effect in p-type GaN layers. The improved electrical and optical properties are believed to be associated with the active participation of isolated Mg impurities.