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Dive into the research topics where Joo-Cheol Shim is active.

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Featured researches published by Joo-Cheol Shim.


Schizophrenia Bulletin | 2011

Cigarette Smoking and Mortality Risk in People With Schizophrenia

Deanna L. Kelly; Robert P. McMahon; Fang Liu; Kristen M. Mackowick; Douglas L. Boggs; Kimberly R. Warren; Stephanie Feldman; Joo-Cheol Shim; Raymond C. Love; Lisa B. Dixon

This study examined effects of cigarette smoking on mortality risk in 1213 persons aged 19-69 years with schizophrenia-related psychotic disorders admitted to State of Maryland Hospitals between 1994 and 2000. Inpatient medical records from 7 hospitals were reviewed to obtain demographic information, diagnosis, medication use, as well as smoking and other substance use. Social Security Death Index data were used to identify deaths in the study group between 1994 and 2004. Death records were reviewed to obtain manner of death and underlying disorders. Of the 1213, 55% were smokers and 71% abused substances. There was an age × smoking interaction (χ(2) = 14.6, df = 1, P = .0001) for mortality, with estimated hazard ratios (HRs) for smokers vs nonsmokers of 2.1 among 35- to 54-year olds and HR of 0.7 among those aged 55-69 years. Five- and 10-year mortality rates for smokers aged 35-54 years were 7.0% and 14.2%, compared with 3.3% and 10.0% for nonsmokers, respectively (χ(2) = 5.53, df = 1, P = .019). Cardiac causes were identified in 43% of deaths in smokers but only 19% of deaths in nonsmokers (P < .006). For those aged 35-54 years, the odds of cardiac related death was increased by 12 fold in smokers relative to nonsmokers (HR = 12.4, χ(2) = 12.0, df = 1, P = .0005). Among people aged 35-54 years, those smoking greater than one pack daily have a significantly increased total mortality risk (HR = 2.7) vs nonsmokers. Cigarette smoking, particularly in people aged 35-54 years, contributes to an increased risk of death. Greater smoking severity significantly increases this risk. Smoking cessation in people with schizophrenia deserves significant attention.


Neuropsychopharmacology | 2012

Adjunctive varenicline treatment with antipsychotic medications for cognitive impairments in people with schizophrenia: a randomized double-blind placebo-controlled trial.

Joo-Cheol Shim; Do-Un Jung; Sung-Soo Jung; Young-Soo Seo; Deuk-Man Cho; Ji-Heon Lee; Sae-Woom Lee; Bo-Geum Kong; Je-Wook Kang; Minkyung Oh; Sang-Duk Kim; Robert P. McMahon; Deanna L. Kelly

The aim of this study is to examine the effects of treatment with varenicline, a partial agonist at the α4β2 and full agonist at the α7 nicotine acetylcholine receptor, on cognitive impairments in people with schizophrenia. In all, 120 clinically stable people with schizophrenia participated in randomized, double-blind, placebo-controlled 8-week trial. Antipsychotic and concomitant medication doses remained fixed throughout the study. Varenicline was titrated up to 1 mg twice daily for weeks 2–8. Neuropsychological, clinical, and safety assessments were administered at baseline and weeks 1, 2, 4, and 8. In the primary analyses of neurocognitive differences at week 8, no varenicline–placebo differences were significant. In secondary longitudinal analyses, varenicline improved compared with placebo on the Digital Symbol Substitution Test (p=0.013) and the Wisconsin Card Sorting Test non-perseverative errors (p=0.043). Some treatment effects were different between smokers and non-smokers. In smokers, Continuous Performance Test hit reaction time (p=0.008) and Stroop Interference (p=0.004) were reduced for varenicline compared with placebo, while there were no treatment differences in non-smokers. No significant treatment main effects or interactions were noted for total scores on the Positive and Negative Syndrome Scale or the Scale for the Assessment for Negative Symptoms. Our findings suggest beneficial effects of adjunctive varenicline treatment with antipsychotics for some cognitive impairments in people with schizophrenia. In some cases, effects of treatment varied between smokers and non-smokers. Further study is required to assess the functional significance of these changes.


Drug Metabolism and Disposition | 2007

Identification and Functional Characterization of Genetic Variants of Human Organic Cation Transporters in a Korean Population

Ho-Jin Kang; Im-Sook Song; Ho Jung Shin; Woo-Young Kim; Choong-Hee Lee; Joo-Cheol Shim; Hong-Hao Zhou; Sang Seop Lee; Jae-Gook Shin

Genetic variants of three human organic cation transporter genes (hOCTs) were extensively explored in a Korean population. The functional changes of hOCT2 variants were evaluated in vitro, and those genetic polymorphisms of hOCTs were compared among different ethnic populations. From direct DNA sequencing, 7 of 13 coding variants were nonsynonymous single-nucleotide polymorphisms (SNPs), including four variants from hOCT1 (F160L, P283L, P341L, and M408V) and three from hOCT2 (T199I, T201M, and A270S), whereas 6 were synonymous SNPs. The linkage disequilibrium analysis presented for three independent LD blocks for each hOCT gene showed no significant linkage among all three hOCT genes. The transporter activities of MDCK cells that overexpress the hOCT2-T199I, -T201M, and -A270S variants showed significantly decreased uptake of [3H]methyl-4-phenylpyridinium acetate (MPP+) or [14C]tetraethylammonium compared with those cells that overexpress wild-type hOCT2, and the estimated kinetic parameters of these variants for [3H]MPP+ uptake in oocytes showed a 2- to 5-fold increase in Km values and a 10- to 20-fold decrease in Vmax values. The allele frequencies of the five functional variants hOCT1-P283L, -P341L, and hOCT2-T199I, -T201M, and -A270S were 1.3, 17, 0.7, 0.7, and 11%, respectively, in a Korean population; the frequency distributions of these variants were not significantly different from those of Chinese and Vietnamese populations. These findings suggest that genetic variants of hOCTs are not linked among three genes in a Korean population, and several of the hOCT genetic variants cause decreased transport activity in vitro compared with the wild type, although the clinical relevance of these variants remains to be evaluated.


The Journal of Clinical Psychiatry | 2010

Cardiovascular disease mortality in patients with chronic schizophrenia treated with clozapine: a retrospective cohort study.

Deanna L. Kelly; Robert P. McMahon; Fang Liu; Raymond C. Love; Joo-Cheol Shim; Kimberly R. Warren; Robert R. Conley

BACKGROUND Cardiovascular disease (CVD) mortality in schizophrenia is more frequent than in the general population. Whether second-generation antipsychotics (SGAs) increase risk of CVD morbidity and mortality has yet to be determined. METHOD We conducted a retrospective cohort study using an administrative database to identify patients with DSM-III- or DSM-IV-diagnosed schizophrenia, treated in Maryland, who started clozapine treatment (n = 1,084) or were never treated with clozapine (initiated on risperidone; n = 602) between 1994 and 2000. Deaths between 1994 and 2004 were identified by the Social Security Death Index, and death records were obtained. RESULTS During the 6- to 10-year follow-up period, there were 136 deaths, of which 43 were attributed to CVD. Cardiovascular disease mortality in patients aged younger than 55 years at medication start was approximately 1.1% (clozapine, 1.1%; risperidone, 1.0%) in both groups at 5 years and 2.7% (clozapine) and 2.8% (risperidone) at 10 years (chi(2)(1) = 0.12, P = .73). Patients who started treatment at ages >or= 55 years had CVD mortality of 8.5% (clozapine) and 3.6% (risperidone) at 5 years and 16.0% (clozapine) and 5.7% (risperidone) at 10 years (chi(2)(1) = 2.13, P = .144). In a Cox regression model, patients aged >or= 55 years were at greater risk of mortality than younger patients (hazard ratio = 4.6, P < .001); whites were at greater risk than nonwhites (HR = 2.1, P = .046); however, SGA treatment (HR = 1.2; 95% CI, 0.6-2.4; P = .61) and sex (HR = 0.9, P = .69) were not statistically significant predictors of CVD, nor was there a significant age x clozapine interaction (chi(2)(1) = 1.52, P = .22). Age-, race-, and gender-adjusted standardized mortality ratios were significantly elevated (clozapine, 4.70; 95% CI, 3.19-6.67; risperidone, 2.88; 95% CI, 1.38-5.30) compared to year 2000 rates for the Maryland general population but did not differ by antipsychotic group (chi(2)(1) = 1.42, P = .23). CONCLUSIONS The risk of CVD mortality in schizophrenia does not differ between clozapine and risperidone in adults despite known differences in risk profiles for weight gain and metabolic side effects. However, we cannot rule out an increased risk of CVD mortality among those starting treatment at ages 55 years or older.


Journal of Clinical Psychopharmacology | 2011

Bone mineral density and osteoporosis risk in older patients with schizophrenia.

Do-Un Jung; Deanna L. Kelly; Minkyung Oh; Bo-Geum Kong; Je-Wook Kang; Seung-Ju Lee; Joo-Cheol Shim

Objective: People with schizophrenia are at a higher risk for osteoporosis. The authors investigated the prevalence of low bone density and its risk factors in older Korean patients with schizophrenia. Method: In cross-sectional study, 327 inpatients with schizophrenia were screened. Among them, 229 patients older than 50 years participated in this study. The control group consisted of healthy volunteers who were of similar ages (n = 125). Bone density was measured in the lumbar spine and the neck, trochanter, and ward regions of the right proximal femur by dual-energy x-ray absorptiometry. Clinical variables such as alcohol use, cigarette smoking, and fracture history were obtained. The Student t test, Pearson &khgr;2 test, Wilcoxon rank sum test, and logistic regression analysis were used. Results: The prevalence of osteoporosis was significantly higher in patients with schizophrenia compared with healthy controls (34.9% vs 18.4%, P = 0.0043). Within the schizophrenia group, female subjects had a significantly higher prevalence of osteoporosis than male subjects (48.4% vs 25.7%, P = 0.0014); however, no sex differences were identified in the healthy control group. The actual bone density and t scores in patients with schizophrenia were significantly lower in all sites than in healthy controls. Among patients with schizophrenia, smokers and alcohol abuser showed lower bone density compared with those who did not smoke or drink. The lifetime prevalence of fracture was significantly higher in patients with schizophrenia (24.0%) compared with healthy controls (5.6%; P = 0.001). Conclusions: Our results emphasize that older patients with schizophrenia are at risk for low bone density. Cigarette smoking and alcohol abuse are associated with low bone density in patients with schizophrenia.


BMC Psychiatry | 2013

Treating symptomatic hyperprolactinemia in women with schizophrenia: presentation of the ongoing DAAMSEL clinical trial (Dopamine partial Agonist, Aripiprazole, for the Management of Symptomatic ELevated prolactin).

Deanna L. Kelly; Amber Earl; Kelli M. Sullivan; Faith Dickerson; Stephanie Feldman; Robert P. McMahon; Robert W. Buchanan; Dale Warfel; William R. Keller; Bernard A. Fischer; Joo-Cheol Shim

Prolactin elevations occur in people treated with antipsychotic medications and are often much higher in women than in men. Hyperprolactinemia is known to cause amenorrhea, oligomenorrhea, galactorrhea and gynecomastia in females and is also associated with sexual dysfunction and bone loss. These side effects increase risk of antipsychotic nonadherence and suicide and pose significant problems in the long term management of women with schizophrenia. In this manuscript, we review the literature on prolactin; its physiology, plasma levels, side effects and strategies for treatment. We also present the rationale and protocol for an ongoing clinical trial to treat symptomatic hyperprolactinemia in premenopausal women with schizophrenia. More attention and focus are needed to address these significant side effects and help the field better personalize the treatment of women with schizophrenia.


Clinical psychopharmacology and neuroscience : the official scientific journal of the Korean College of Neuropsychopharmacology | 2015

The Relationship between Language Ability and Cognitive Function in Patients with Schizophrenia.

Sung-Jin Kim; Joo-Cheol Shim; Bo-Geum Kong; Je-Wook Kang; Jung-Joon Moon; Dong-Wook Jeon; Sung-Soo Jung; Beom-Joo Seo; Do-Un Jung

Objective Cognitive dysfunction is common in people with schizophrenia, and language disability is one of the most notable cognitive deficits. This study assessed the use and comprehension ability of the Korean language in patients with schizophrenia and the correlations between language ability and cognitive function. Methods Eighty-six patients with schizophrenia and a group of 29 healthy controls were recruited. We assessed both clinical symptoms and cognitive functions including Korean language ability. For clinical symptoms, the Positive and Negative Syndrome Scale, Clinical Global Impression-Schizophrenia Scale, and Social and Occupational Functioning Assessment Scale were used. For the Korean language ability assessment, a portion of the Korean Broadcasting System (KBS) Korean Language Test was used. The Short-form of Korean-Wechsler Adult Intelligence Scale, the Korean version of the University of California San Diego (UCSD) Performance-based Skills Assessment (K-UPSA), and the Wisconsin Card Sorting Test (WCST) were used to assess cognitive functions. Results Schizophrenic patients had significantly lower scores in the language and cognitive function tests both in the total and subscale scores. Various clinical scores had negative correlations with reading comprehension ability of the KBS Korean Language Test. The WCST and a part of the K-UPSA had positive correlations with multiple domains of the language test. Conclusion A significant difference was found between schizophrenic patients and controls in language ability. Correlations between Korean language ability and several clinical symptoms and cognitive functions were demonstrated in patients with schizophrenia. Tests of cognitive function had positive correlations with different aspects of language ability.


Schizophrenia Research | 2016

Adjunctive varenicline treatment for smoking reduction in patients with schizophrenia: A randomized double-blind placebo-controlled trial

Dong-Wook Jeon; Joo-Cheol Shim; Bo-Geum Kong; Jung-Joon Moon; Young-Soo Seo; Sung-Jin Kim; Minkyung Oh; Do-Un Jung

OBJECTIVES Smoking is more common among patients with schizophrenia than it is in the general population. Varenicline, a partial and full agonist at the α4β2 and α7 nicotine acetylcholine receptors, respectively, has been shown to be an effective anti-smoking treatment. This study examined the effects of varenicline treatment on smoking reduction in patients with schizophrenia. METHODS Sixty smokers with schizophrenia were recruited and randomized to receive either varenicline or placebo. Smoking behavior was assessed with the Minnesota Nicotine Withdrawal Scale (mNWS), Brief Questionnaire of Smoking Urge (QSU-brief), and Modified Cigarette Evaluation Questionnaire (mCEQ). Exhaled carbon monoxide was also measured to assess smoking dependency and status. Data were analyzed with the two-tailed Students t-test, χ(2) test, and repeated measures ANOVA. RESULTS During the 8-week study, there was a significant time×group interaction, which showed that smoking decreased over time in the varenicline group. Expired CO levels also decreased in the varenicline group, showing a significant time effect, group effect, and time×group interaction. Total mCEQ scores decreased in the varenicline group, demonstrating a significant time×group interaction. Among the five domains of the mCEQ, the smoking satisfaction, psychological reward, and enjoyment of respiratory tract sensation domains showed significant time×group interactions in the varenicline group. The QSU-brief and mNWS demonstrated a significant time effect, but not significant time×group interactions. Adjunctive varenicline treatment with antipsychotics was generally well-tolerated and safe. CONCLUSIONS Varenicline showed significant efficacy in reducing smoking in people with schizophrenia.


Clinical Psychopharmacology and Neuroscience | 2017

The Korean Version of the University of California San Diego Performance-based Skills Assessment: Reliability and Validity

Sung-Jin Kim; Jung-Min Kim; Joo-Cheol Shim; Beom-Joo Seo; Sung-Soo Jung; Jeoung-Whan Ryu; Young-Soo Seo; Yu-Cheol Lee; Jung-Joon Moon; Dong-Wook Jeon; Kyoung-Duck Park; Do-Un Jung

Objective The study’s aim was to develop and standardize a Korean version of the University of California San Diego Performance-based Skills Assessment (K-UPSA), which is used to evaluate the daily living function of patients with schizophrenia. Methods Study participants were 78 patients with schizophrenia and 27 demographically matched healthy controls. We evaluated the clinical states and cognitive functions to verify K-UPSA’s reliability and validity. For clinical states, the Positive and Negative Syndrome Scale, Clinical Global Impression-Schizophrenia scale, and Social and Occupational Functioning Assessment Scale and Schizophrenia Quality of Life Scale-fourth revision were used. The Schizophrenia Cognition Rating Scale, Short-form of Korean-Wechsler Adult Intelligence Scale, and Wisconsin Card Sorting Test were used to assess cognitive function. Results The K-UPSA had statistically significant reliability and validity. The K-UPSA has high internal consistency (Cronbach’s alpha, 0.837) and test-retest reliability (intra-class correlation coefficient, 0.381–0.792; p<0.001). The K-UPSA had significant discriminant validity (p<0.001). Significant correlations between the K-UPSA’s scores and most of the scales and tests listed above demonstrated K-UPSA’s concurrent validity (p<0.001). Conclusion The K-UPSA is useful to evaluate the daily living function in Korean patients with schizophrenia.


International Journal of Psychiatry in Clinical Practice | 2015

Differences in cognitive function and daily living skills between early- and late-stage schizophrenia.

Sung-Jin Kim; Joo-Cheol Shim; Bo-Geum Kong; Je-Wook Kang; Jung-Joon Moon; Dong-Wook Jeon; Young-Soo Seo; Minkyung Oh; Do-Un Jung

Objectives. Cognitive dysfunction is a core feature of schizophrenia; deficits often manifest prior to diagnosis and persist throughout the course of the illness. This study was performed to assess the difference in cognitive function and daily living skills between the early- and late-stage schizophrenia. Methods. Fifty-five clinically stable patients with schizophrenia were recruited (25 with < 5-year and 30 with > 5-year disease durations). We evaluated subjects’ clinical states, cognitive function, and psychosocial factors. The Korean versions of MATRICS Consensus Cognitive Battery and UCSD Performance-based Skills Assessment were used for evaluating cognitive function and daily living skills. Chi-square, Wilcoxon rank sum, and t-tests were used to analyze the data. Results. The two groups did not differ for most demographic variables. No significant differences between groups were found for clinical symptoms, psychosocial factors, or non-social cognitive domains. However, the early-stage group had higher social cognition domain scores than the late-stage group (p = 0.01). Early-stage patients scored significantly higher than those in the late-stage group did in the communication and comprehension/planning domains (p = 0.037 and 0.027, respectively), and total score (p = 0.003) of the Performance-based Skills Assessment. Conclusions. We observed significant differences between patients with early- and late-stage illness with regard to social cognition and performance-based skills.

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