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Biomedical subjects

In Kyoon Lyoo

Publications and source records attributed to In Kyoon Lyoo.

At least 55 records · Page 3Linked to original sources

White matter hyperintensities and their associations with suicidality in psychiatrically hospitalized children and adolescents.

OBJECTIVE: Increasingly, researchers and clinicians are recognizing that there may be biological markers associated with increased risk of suicide. The objective of this study was to compare white matter hyperintensities in psychiatrically hospitalized children and youth with and without a history of suicide attempt while controlling for other variables. METHOD: White matter hyperintensities of 153 child and adolescent psychiatry inpatients were rated on T2-weighted magnetic resonance imaging scans using a modified Coffey scale. DSM-IV diagnosis, history of suicide attempt, and control variables such as gender, age, comorbid medical illnesses, developmental disorder, substance abuse, severity of mental illness, head injury, and possible cerebral hypoxia were obtained from discharge medical records. RESULTS: Within the unipolar depression group (n = 48), white matter hyperintensities were significantly associated with a higher prevalence of past suicide attempts (Fisher exact test, p =.03). Logistic regression analysis confirmed this relationship, indicating that none of the control variables confounded our results and suggesting a specificity of 0.94. CONCLUSIONS: This is the first report of an increased prevalence of white matter hyperintensities in children and youth with unipolar depression and a history of suicide attempt. Replication and expansion of our preliminary findings could be of great clinical interest.

Adolescent↗

Three-year follow up of women with and without borderline personality disorder: development of Cloninger's character in adolescence.

The purpose of the present study was to examine the developmental patterns of Cloninger's biogenetic character traits in subjects with borderline personality disorder (BPD). Study subjects met Diagnostic and Statistical Manual of Mental Disorders (3rd edn, revised; DSM-III-R) criteria for BPD without comorbid axis I or II disorders, as determined by the Diagnostic Interview for Borderlines-Revised, Structured Clinical Interview for the DSM-III-R, and Diagnostic Interview for Personality Disorders. The BPD subjects and age- and sex-matched healthy comparison subjects were initially interviewed for Cloninger's biogenetic characters and re-interviewed at an interval of 1 year for the following 3 years. There were significant differences in the developmental patterns of self-directedness, cooperativeness, and self-transcendence between BPD and healthy comparison subjects (significant group by time interaction: repeated measures manova, F = 17.3, d.f. = 3,240, P < 0.001; F = 28.5, d.f. = 3,240, P < 0.001; F = 4.7, d.f. = 3,240, P < 0.01, respectively). The BPD subjects had less changes in character-related maturity with increasing age than did healthy comparison subjects. Post-hoc tests with Duncan's statistics revealed that subjects with BPD had significantly lower scores on self-directedness at all assessment time periods (P < 0.01) and lower scores on cooperativeness at the second-year and third-year follow-up assessments as compared to healthy comparison subjects (P < 0.01). The BPD subjects had a distinctively different developmental pattern of Cloninger's character compared to healthy comparison subjects. The character development of BPD patients was more fixed and immature than those of healthy comparison subjects.

Adolescent↗

Trait and state aspects of harm avoidance and its implication for treatment in major depressive disorder, dysthymic disorder, and depressive personality disorder.

The authors evaluated the trait/state issues of harm avoidance in depressive-spectrum disorders and its predictive potential for antidepressant response. Subjects with Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) major depressive disorder (n = 39), dysthymic disorder (n = 37), depressive personality disorder (n = 39), and healthy control subjects (n = 40) were evaluated with the Temperament and Character Inventory and the 17-item Hamilton Depression Rating Scale (HDRS-17) at baseline and after a 12 week antidepressant treatment period. Higher harm avoidance scores predicted lesser improvement in subjects with dysthymic disorder and major depressive disorder, as determined by lesser decrease in HDRS-17 scores. Mean harm avoidance scores in depressed subjects were consistently greater than those in healthy controls, controlling for age, gender and diagnosis. Mean harm avoidance scores decreased significantly in all depressive-spectrum disorders after treatment, but still remained higher than harm avoidance scores in control subjects. The present study reports that harm avoidance is a reliable predictor of antidepressant treatment in subjects with major depressive disorder and dysthymic disorder and that harm avoidance is both trait- and state-dependent in depressive-spectrum disorders.

Adult↗

Attention deficit hyperactivity symptoms and internet addiction.

The objective of this study was to evaluate the relationship between attention deficit-hyperactivity/impulsivity symptoms and Internet addiction. In total, 535 elementary school students (264 boys, 271 girls; mean age, 11.0 +/- 1.0 years) were recruited. The presence or severity of Internet addiction was assessed by the Young's Internet Addiction test. Parents and teachers of the children completed the DuPaul's attention deficit hyperactivity disorder (ADHD) rating scale (ARS; Korean version, K-ARS) and Child Behavior Checklists. Children with the highest and lowest quartiles in K-ARS scores were defined to be in ADHD and non-ADHD groups, respectively. Five children (0.9%) met criteria for a definite Internet addiction and 75 children (14.0%) met criteria for a probable Internet addiction. K-ARS scores had significant positive correlations with Young's Internet Addiction test scores. The Internet addiction group had higher total scores of K-ARS and ADHD-related subcategories in the Child Behavior Checklists than the non-addiction group. The ADHD group had higher Internet addiction scores compared with the non-ADHD group. Therefore, significant associations have been found between the level of ADHD symptoms and the severity of Internet addiction in children. In addition, current findings suggest that the presence of ADHD symptoms, both in inattention and hyperactivity-impulsivity domains, may be one of the important risk factors for Internet addiction.

Attention Deficit Disorder with Hyperactivity↗

White matter hyperintensities in subjects with bipolar disorder.

There have been divergent reports on the prevalence and severity of white matter hyperintensities (WMH) on brain magnetic resonance (MR) images in subjects with bipolar disorder. In the present study, evaluations were made on the prevalence and severity of WMH in subjects with bipolar disorder using contiguous 3-mm thick MR slices as well as fluid attenuated inversion recovery (FLAIR) images. A detailed WMH rating system was employed to assess these WMH. A total of 43 bipolar patients, as diagnosed by the Structured Clinical Interview from the Diagnostic and Statistical Manual-IV (SCID-IV), and 39 healthy comparison subjects were scanned using a 1.5-T whole body GE magnetic resonance scanner. WMH were assessed with a modified composite version of the Fazekas' and Coffey's rating scales to detect less severe WMH. Periventricular and subcortical WMH were coded separately. Subjects with bipolar disorder had greater prevalence of WMH abnormalities than comparison subjects (Bipolar, grade 1 = 11.6%, grade 2 = 9.3%, grade 3 = 7.0%; Comparison, grade 1 = 5.1%, grade 2 = 2.6%, grade 3 = 0%). This difference is mainly due to the differences in deep WMH (Bipolar, grade 1 = 14.0%, grade 2 = 14.0%; Comparison, grade 1 = 7.7%, grade 2 = 0%). The current study confirms the higher prevalence of WMH in subjects with bipolar disorder. Differences of small-sized WMH abnormalities between groups were successfully detected using a large number of bipolar subjects and thinner sliced MR images with FLAIR.

Adult↗

Reduced cortical gray matter density in human MDMA (Ecstasy) users: a voxel-based morphometry study.

The popular recreational drug, 3,4-methylenedioxymethamphetamine (MDMA) exerts its actions in part via blockade of serotonin and dopamine reuptake. Many animal and human studies have demonstrated long-lasting reductions in measures of central nervous system (CNS) serotonin function following MDMA administration. One emerging role of serotonin function in the CNS is a positive trophic effect via stimulation of intracellular signaling pathways and trophic factors. We hypothesized that human MDMA users might display neocortical gray matter reductions due to loss of serotonergically mediated trophic effects on cortical cells. However, unlike animal models, most human MDMA users worldwide are polydrug users, thereby complicating the assessment of MDMA toxicity in this group. Structural magnetic resonance imaging (MRI) scans of 31 MDMA polydrug users versus 29 non-MDMA users were compared using voxel-based morphometry (VBM) to assess regional brain gray and white matter concentration. VBM employs gray/white matter segmentation and statistical parametric mapping (SPM) analysis to calculate a voxel-wise comparison of regional gray or white matter concentration. Using this method, we consistently found several brain regions having decreased gray matter concentration in MDMA polydrug users. These regions were localized to neocortex in bilateral Brodmann area (BA) 18, left BA 21, and left BA 45, as well as bilateral cerebellum, and midline brainstem. Overall, these preliminary findings suggest that MDMA polydrug users have multiple regions of gray matter reduction, potentially accounting for previously reported neuropsychiatric impairments in MDMA users. Additional animal model and human studies of the CNS effects of MDMA and combined MDMA-polydrug toxicity are needed to further explain these findings. Potential explanations for our results including pre-existing brain differences predisposing to MDMA polydrug use, direct MDMA and polydrug toxicity, indirect changes due to MDMA and polydrug toxicity, or combinations of all these factors.

Adolescent↗

Multinuclear magnetic resonance spectroscopy of high-energy phosphate metabolites in human brain following oral supplementation of creatine-monohydrate.

Alterations in brain high-energy phosphate metabolism, determined by in vivo magnetic resonance spectroscopy (MRS), have been reported in subjects with a number of brain disorders including major depression, schizophrenia, and substance abuse. It is not clear to what extent these changes can be modified by pharmacological or nutritional means. To address this possibility, we evaluated changes in brain chemistry that were associated with oral creatine (Cr) administration. We hypothesized that oral Cr supplementation, by increasing brain creatine and high-energy phosphate stored in phosphocreatine, would result in an increase in the creatine resonance, as measured using proton 1H-MRS, and a decrease in the beta-nucleoside triphosphate (NTP) peak and an increase in the phosphocreatine (PCr) peak, as measured by phosphorus 31P-MRS, in brain of healthy human subjects. Fifteen healthy male subjects (age=22.9+/-2.2; body mass index=22.9+/-1.7), who were without any axis I disorders or physical or neurological illness, were recruited. Ten subjects took creatine-monohydrate, 0.3 g/kg/day for the first 7 days and 0.03 g/kg/day for the next 7 days (creatine group). Five comparison subjects took equivalent amounts of sucrose as placebo (placebo group). Both 1H- and 31P-MRS scans were acquired at baseline, as well as at day 7 and day 14 of oral supplementation. 1H-MRS: Water suppressed localized spectra were acquired using a single-voxel (1.5 cm x 2 cm x 2 cm) proton MRS PRESS sequence in the left frontal lobe. 31P-MRS: Phosphorus spectral data were recorded from a 5-cm-thick axial brain slice using a short-TE slice selective spin-echo pulse sequence. The creatine group had significantly increased brain creatine levels (8.1% and 9.3%, in creatine/N-acetyl aspartate and creatine/choline ratios, respectively) compared to the placebo group over the 2-week period. The creatine group had significantly decreased beta-NTP levels (7.8%) and marginally increased PCr (3.4%) over the same period. In addition, the brain inorganic phosphate level increased over the same period in the creatine group (9.8%). The current study is the first multinuclear (1H and 31P) MRS study to evaluate changes in brain high-energy phosphate metabolism following oral creatine supplementation in healthy human subjects. These findings suggest the possibility of using oral creatine supplementation to modify brain high-energy phosphate metabolism in subjects with various brain disorders, including major depression, schizophrenia, cocaine and opiate abuse, where alterations in brain high-energy phosphate metabolism have been reported.

Administration, Oral↗

Neural correlates of clinical symptoms and cognitive dysfunctions in obsessive-compulsive disorder.

Although results from neuropsychological and neuroimaging studies have postulated the involvement of the frontal lobe and the subcortical brain regions in the pathophysiology of obsessive-compulsive disorder (OCD), neuroimaging studies have provided little evidence that cognitive abnormalities in patients with OCD are related to dysfunctions in these areas. This study was designed to determine whether the clinical features and cognitive deficits of OCD might be taken to reflect frontal-subcortical dysfunction. Fourteen patients with OCD and 14 case-matched normal subjects completed clinical and cognitive evaluation, including four sets of neuropsychological tests that assessed the executive functions and visual memory. Cerebral glucose metabolic rates were measured by using positron emission tomography (PET) with 18F-fluorodeoxyglucose. Behavioral and PET data were analyzed using statistical parametric mapping for group differences and behavioral-metabolic correlates. The right orbitofrontal cortex showed increased metabolic activity and the left parieto-occipital junction showed decreased metabolic activity in patients. Metabolism in the right hippocampus, the left putamen and the right parietal region was associated with the severity of obsessive-compulsive symptoms. Correlations between metabolic rates and neuropsychological test scores in the prefrontal cortex and the putamen occurred only in the patient group. These results suggest that patients with OCD have distinct features of brain metabolic activities for performing cognitive tasks as well as presenting obsessive-compulsive symptoms. In particular, the frontal-subcortical circuits might mediate not only symptomatic expression but also cognitive expression in patients with OCD.

Adult↗

Oral choline decreases brain purine levels in lithium-treated subjects with rapid-cycling bipolar disorder: a double-blind trial using proton and lithium magnetic resonance spectroscopy.

OBJECTIVES: Oral choline administration has been reported to increase brain phosphatidylcholine levels. As phospholipid synthesis for maintaining membrane integrity in mammalian brain cells consumes approximately 10-15% of the total adenosine triphosphate (ATP) pool, an increased availability of brain choline may lead to an increase in ATP consumption. Given reports of genetic studies, which suggest mitochondrial dysfunction, and phosphorus (31P) magnetic resonance spectroscopy (MRS) studies, which report dysfunction in high-energy phosphate metabolism in patients with bipolar disorder, the current study is designed to evaluate the role of oral choline supplementation in modifying high-energy phosphate metabolism in subjects with bipolar disorder. METHODS: Eight lithium-treated patients with DSM-IV bipolar disorder, rapid cycling type were randomly assigned to 50 mg/kg/day of choline bitartrate or placebo for 12 weeks. Brain purine, choline and lithium levels were assessed using 1H- and 7Li-MRS. Patients received four to six MRS scans, at baseline and weeks 2, 3, 5, 8, 10 and 12 of treatment (n = 40 scans). Patients were assessed using the Clinical Global Impression Scale (CGIS), the Young Mania Rating Scale (YRMS) and the Hamilton Depression Rating Scale (HDRS) at each MRS scan. RESULTS: There were no significant differences in change-from-baseline measures of CGIS, YMRS, and HDRS, brain choline/creatine ratios, and brain lithium levels over a 12-week assessment period between the choline and placebo groups or within each group. However, the choline treatment group showed a significant decrease in purine metabolite ratios from baseline (purine/n-acetyl aspartate: coef = -0.08, z = -2.17, df = 22, p = 0.030; purine/choline: coef = -0.12, z = -1.97, df = 22, p = 0.049) compared to the placebo group, controlling for brain lithium level changes. Brain lithium level change was not a significant predictor of purine ratios. CONCLUSIONS: The current study reports that oral choline supplementation resulted in a significant decrease in brain purine levels over a 12-week treatment period in lithium-treated patients with DSM-IV bipolar disorder, rapid-cycling type, which may be related to the anti-manic effects of adjuvant choline. This result is consistent with mitochondrial dysfunction in bipolar disorder inadequately meeting the demand for increased ATP production as exogenous oral choline administration increases membrane phospholipid synthesis.

Administration, Oral↗

An alternative way to individualized medicine: psychological and physical traits of Sasang typology.

BACKGROUND: Disease susceptibility and drug response of individuals are presumed to be different depending on their personality traits. The Sasang typology, a traditional Korean medical typology, explains the individual differences of vulnerability to pathology and proposes guidelines for the safe and effective use of medical herbs depending on individual traits. OBJECTIVE: The purpose of the present study was to evaluate psychologic and physical characteristics of Sasang types from the perspective of personality theory. DESIGN: After determining the Sasang type of 79 college students based on the Questionnaire for the Sasang Constitution Classification, the psychologic and physical traits of each type were analyzed by the Meyers-Briggs Type Indicator (MBTI) and Bioelectrical Impedance Analysis, respectively. RESULTS: Each of the Sasang types showed significantly different profiles based on the MBTI scores (generalized estimation equation, coefficient = 11.88, z = 2.13, p = 0.033) and could be distinctively classified based on their MBTI scores (discriminant analysis Wilks' lambda = 0.611, df = 8, chi(2) = 36.7, p < 0.001). Subjects with the So-Eum type (Introversion and Judging) and the So-Yang type (Extroversion and Perceiving) showed contrasting psychologic features. However, they had similar anthropometric characteristics. Subjects with Tae-Eum type had relatively higher body fat mass. CONCLUSION: Current results demonstrated distinctive personality traits associated with Sasang types using reproducible psychometric and anthropometric instruments. With further study, the Sasang typology could serve as a scientific tool for individualized and integrative medicine.

Adult↗

Subanalysis of the location of white matter hyperintensities and their association with suicidality in children and youth.

Our previous research with psychiatrically hospitalized children and youth indicates that white matter hyperintensities (WMH) on T2-weighted MRI images are associated with a history of suicide attempt. This subanalysis of the specific locations of the WMH suggests that youth with deep WMH in the parietal lobe but not in the frontal lobe have a significantly higher prevalence of reported past suicide attempt.

Adolescent↗

Decrease in genu of the corpus callosum in medication-naïve, early-onset dysthymia and depressive personality disorder.

BACKGROUND: The purpose of this study was to detect differences in regional areas of the corpus callosum (CC) in subjects with early-onset minor depression (dysthymia or depressive personality disorder) and healthy comparison subjects. Based on previous reports that have suggested reduced frontal lobe volume and reduced hemispheric lateralization in the frontal regions of the brain in depression, we hypothesized that the area of the CC that interconnects the frontal regions of the brain, i.e., the genu, will be smaller compared to that of healthy comparison subjects. METHODS: Forty female subjects with early-onset dysthymia or depressive personality disorder, as defined by the Structured Clinical Interview for DSM-III-R and the Diagnostic Interview for Depressive Personality, respectively, and age- and gender-matched healthy comparison subjects (n = 42) were recruited (age: 21.4 +/- 2.1 and 20.9 +/- 2.8 years, respectively). All subjects were psychotropic medications-naïve and right-handed. A 1.5T GE Sigma scanner was used to acquire 124 1.5-mm-thick contiguous coronal images. Midsagittal slice images were carefully selected from reconstructed magnetic resonance images both from native and stereotaxic space to measure seven regional areas of the CC. RESULTS: There were significant diagnosis by CC region interactions [F(6,480) = 4.06, p <.001; F(6,480) = 3.30, p =.003, native and stereotaxic space, respectively]. Early-onset minor depression subjects had a 9.9% (native space) and 6.9% (stereotaxic space) smaller genu of the CC compared to the healthy comparison subjects (the Newman-Keuls post hoc test, p =.005 and.019, native and stereotaxic space, respectively). Early-onset minor depression subjects also had a 7.8% smaller posterior midbody relative to the comparison subjects (the Newman-Keuls post hoc test, p =.033) only in the native space. Severity of current depressive symptoms or duration of illness did not correlate with the size of the genu or the posterior midbody parts of the CC. CONCLUSIONS: These results suggest frontal lobe structural, and possibly functional, abnormalities in the brain in young female adults with a milder spectrum of depression, i.e., DSM-IV early-onset dysthymia or depressive personality disorder. The present findings point out the possible role of frontal lobe abnormality in pathophysiology of early-onset minor depression.

Adolescent↗

Modulation of brain and serum glutamatergic concentrations following a switch from conventional neuroleptics to olanzapine.

BACKGROUND: Recent evidence suggests that effects upon glutamatergic transmission may contribute to the therapeutic action of certain atypical antipsychotic agents. METHODS: Glutamate concentrations were measured in serum and were estimated (Glx/Cr) in cingulate cortex by proton magnetic resonance spectroscopy (MRS) in schizophrenia patients while they were being treated with conventional neuroleptics and then 8 weeks after switching to olanzapine. Serum glutamate concentrations were obtained from 11 subjects, and MRS estimates of Glx/Cr were available from 10 subjects at both time points. RESULTS: Serum glutamate concentrations significantly increased after the switch from conventional agents to olanzapine; brain glutamate (Glx/Cr) did not change significantly; however, brain glutamate (Glx/Cr) concentrations increased significantly in patients who exhibited an improvement in negative symptoms with olanzapine compared with patients with no change or worsening of negative symptoms. CONCLUSIONS: Comparisons performed following the switch from conventional agents to olanzapine are consistent with previous studies of clozapine and provide additional preliminary evidence supporting the hypothesis that effects on excitatory amino acid activity may contribute to olanzapine's efficacy for treating negative symptoms.

Adult↗

Magnetic resonance spectroscopy: current and future applications in psychiatric research.

Magnetic resonance spectroscopy (MRS) provides a useful method for studying a number of psychotropic medications and metabolites in human brain in vivo. New insights regarding the pharmacokinetic and pharmacodynamic properties of psychotropic medications in the target organ (i.e., brain) have been obtained using lithium-7 MRS and fluorine-19 MRS. Both proton and phosphorus-31 MRS have significantly enhanced our knowledge of the pathophysiology of a number of psychiatric disorders by providing estimates of brain concentrations of several important cerebral metabolites. Efforts are also being made to link MRS measures of cerebral metabolism with neurophysiologic and neurocognitive processes. Ongoing improvement and refinement in MRS techniques, including the installation of scanners with increased magnetic field strength and better methods of data processing, will improve both spatial and temporal resolution. In addition, efforts to develop multisite research studies may result in greater standardization of MRS procedures and methods for interpretation of results. In this review, the current status of MRS applications in psychiatric research is reviewed, and new frontiers and possible future developments are discussed.

Brain↗

Brain single photon emission computed tomography findings in depressive pseudodementia patients.

BACKGROUND: Recently, there have been studies suggesting that depressive pseudodementia would include early-stage dementing disorder. Through the comparison of the 99mTc-HMPAO single photon emission computed tomography (SPECT) image of depressive pseudodementia subjects, healthy comparison subjects, depressed subjects free of cognitive impairment, and dementia of Alzheimer's type (DAT) subjects, we aimed to see part of pathophysiology of the depressive pseudodementia of elderly patients. METHODS: Study subjects consisted of seven patients with depressive pseudodementia, seven healthy comparison subjects, seven patients with depression free of cognitive impairment, and eleven patients with DAT. Depression patients were diagnosed according to DSM-III-R. DAT patients were diagnosed by DSM III-R and NINCDS-ADRDA criteria of DAT. Other measures for assessment include Hamilton Rating Scale for Depression and Mini Mental State Exam. All underwent 99mTc-HMPAO SPECT scan. The images of each group were analyzed using statistical parametric mapping of Friston, which compares the images on voxel-by-voxel basis. RESULTS: The results were as follows (1) The DAT group showed significant decreases of cerebral blood flow (CBF) in the right frontal, right temporal region, and both parietal regions as compared with control group (P < 0.05). (2) The depression group showed a significant decrease of CBF in the left frontal region as compared with control group (P < 0.05). (3) The depressive pseudodementia group showed significant decreases of CBF in both parietal regions as compared with control group (P < 0.05). (4) The depressive pseudodementia group showed significant decreases of CBF in the right temporal region and both parietal regions as compared with depression group (P < 0.05). (5) The DAT group showed significant decreases of CBF in the right temporal region, both frontal regions, and both parietal regions as compared with depressive pseudodementia group (P < 0.05). LIMITATIONS: The small number of subjects may make it difficult to generalize from our results. Because decreased CBF in depressive pseudodementia is found while the subjects were depressed, we cannot tell whether it is a state marker or a trait marker. CONCLUSIONS: The depressive pseudodementia group showed decreased CBF in the temporo-parietal region, similar to that of the DAT group and different from that of the depression group.

Aged↗

Relationship between personality trait and regional cerebral glucose metabolism assessed with positron emission tomography.

There have been no studies systematically investigating relationships between biogenetic temperament dimensions and patterns of brain glucose metabolism. Nineteen healthy subjects were evaluated regarding the biogenetic temperament using Cloninger's Temperament and Character Inventory (TCI). In addition, [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET) was used to measure regional brain glucose metabolism. Voxel-based correlation analysis was used to test correlations between regional brain glucose metabolism and scores on the TCI. We identified that each temperament dimension, such as Novelty Seeking, Harm Avoidance, and Reward Dependence, was significantly correlated with specific brain regions. The majority of correlations were observed in the areas of paralimbic regions and temporal lobes. The current study provides evidence linking each biogenetic temperament dimension with specific brain areas and provides a promising base for future personality research.

Adolescent↗

The reliability and validity of the junior temperament and character inventory.

The purpose of this study was to evaluate the reliability and validity of the Junior Temperament and Character Inventory (Junior TCI), a child and adolescent version of the Adult Temperament and Character Inventory (TCI), which is based on Cloninger's biosocial model of personality. The Junior TCI was translated into Korean and administered to 663 Korean middle school students (male/female, 360/303; age, 13.3 +/- 1.0 years) and their parents (mother/father, 444/84). Internal consistency was calculated by Cronbach alpha. A test-retest study of the Junior TCI was conducted across a 3-month interval with 97 subjects. Factor analyses for the temperament and character dimensions were performed using principal component analysis, rotating factors by Promax. Cronbach alpha values of the Junior TCI scales ranged from.48 to.80 for the temperament scales and from.64 to.68 for the character scales. Test-retest correlations ranged from.62 to.85 for the temperament scales and from.76 to.79 for the character scales. Principal component factor analyses showed three factors out of four temperament scales (Harm Avoidance 1 to 4; Novelty Seeking 1 to 4; Persistence; and Reward Dependence 1, 3, 4) and three factors out of three character scales (Self-Directedness 1 to 5; Cooperativeness 1 to 5; and Self-Transcendence 1 to 3) that were similar to factor structures of adult versions of the TCI. Explorative factor analysis with a condition of eigenvalue greater than 1 produced six factors, as compared to seven factors extracted in Cloninger's original report of the adult TCI. In conclusion, this was the first study to tests and report detailed psychometric properties of the Junior TCI. The current study confirms that the Junior TCI has satisfactory psychometric properties for the use in child and adolescent populations and reflects Cloninger's biosocial model of personality.

Adolescent↗

Shape changes of the corpus callosum in abstinent methamphetamine users.

The objective of the current study was to evaluate structural changes of the corpus callosum (CC) in abstinence methamphetamine (MA) users. Shape and size of the CC in 27 MA users were compared to those of 18 healthy comparison subjects. To define the local curvature and width of the CC, medial model-based shape analysis was performed using CC skeletons extracted from a distance map. To define the local displacement of the CC, a boundary model-based shape analysis was performed. In addition, the size of regional areas of the CC was measured according to the Witelson's definition for comparison. In the medial model-based shape analysis, increased curvature in the genu (curvature angle difference = 4.1 degrees) and decreased width in posterior midbody (width difference = 0.77 mm) and isthmus area (width difference = 0.86 mm) of the CC were observed in MA users relative to healthy comparison subjects. In the boundary model-based shape analysis, significant displacement was observed in MA users where there were differences in shape/width patterns by the medial model-based shape analysis. There were no differences in the size of regional areas of the CC between groups. Findings suggest that MA use is associated with regional changes in interhemispheric white matter tracts, which connect frontal and parietal cortices and that these frontal and parietal abnormalities may underlie clinical manifestations of the MA abuse.

Adult↗