Ain Chung

Attention deficit hyperactivity symptoms and Internet addiction

Abstract  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 Youngs Internet Addiction test. Parents and teachers of the children completed the DuPauls 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 Youngs 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.

Decreased frontal white-matter integrity in abstinent methamphetamine abusers.

This study explored differences in frontal white-matter (WM) integrity between methamphetamine (MA) abusers and healthy comparison subjects using diffusion tensor imaging (DTI). Fractional anisotropy (FA) values, which indicate WM integrity, were calculated for regions-of-interest in frontal WM on diffusion tensor images of 32 MA abusers and 30 healthy comparison subjects. Frontal executive functions were also assessed by the Wisconsin Card Sorting test (WCST). MA abusers had significantly lower FA values in bilateral frontal WM at the anterior commissure-posterior commissure (AC-PC) plane and the right frontal WM 5 mm above the AC-PC plane relative to healthy comparison subjects. MA abusers had more total, perseveration and non-perseveration errors in the WCST relative to healthy comparison subjects. FA values of the right frontal WM 5 mm above the AC-PC plane negatively correlated with the number of total and non-perseveration errors in the WCST in MA abusers. In the sub-analysis for gender differences, lower FA values in frontal WM and more errors in the WCST were found only in male MA abusers, not in female MA abusers, relative to comparison subjects of the respective gender. We report that frontal WM integrity of MA abusers is compromised. This finding may also be related to impairment in frontal executive function. In addition, the neurotoxic effect of MA on frontal WM may be less prominent in women than in men, possibly due to oestrogens neuroprotective effect.

Asymmetrically altered integrity of cingulum bundle in posttraumatic stress disorder

Previously, our group reported the altered white matter tract integrity of the left anterior cingulate in posttraumatic stress disorder (PTSD) in whole-brain exploration. Current study intended to explore whether the alteration was more prominent in any specific regions of the cingulum bundle. Diffusion tensor images of 21 PTSD subjects and 21 healthy comparison subjects were acquired. Eight isocubic regions of interest (ROIs), i.e. bilateral rostral, subgenual, dorsal, and upper cingulum bundle, were selected. Fractional anisotropy values in each ROI, which indicate the white matter tract integrity, were measured and compared between groups. Relative to comparison subjects, PTSD subjects had significantly smaller fractional anisotropy values in the left side of rostral, subgenual and dorsal cingulum bundle (26.7, 25.0, 22.2% decrease, respectively), but not in the right side ROIs. We report an asymmetrical alteration of the cingulum bundle in PTSD.

Biogenetic temperament and character and attention deficit hyperactivity disorder in Korean children

Background: The objective of this study was to evaluate the relationship between symptoms of attention deficit hyperactivity disorder (ADHD) and biogenetic temperament, as assessed by the Junior Temperament and Character Inventory (JTCI) in Korean elementary school children. Sampling and Methods: Five hundred and sixteen elementary school students (254 boys and 262 girls; age range 9–14 years, mean age 11.0 ± 1.0 years) were studied. The Junior Temperament and Character Inventory, both the self-rating and parent rating scales, the DuPaul ADHD rating scale (ARS-IV) for parents and teachers and the Child Behavior Checklist have been completed by study subjects. Children with high ARS-IV scores (the upper 10th percentile, n = 52) were defined to have ADHD. Fifty-two age- and sex-matched non-ADHD control subjects were selected randomly from a pool of 464 subjects. Results: Inattention and hyperactivity/impulsivity symptoms correlated positively with Novelty Seeking in both children and parent ratings. These symptoms correlated negatively with Persistence, Self-Directedness and Cooperativeness. Novelty Seeking also had significant correlations with attention problems, delinquent behavior, aggressive behavior, externalizing problems and social problems in the Child Behavior Checklist. The ADHD group (n = 52) had higher scores of Novelty Seeking and lower scores of Self-Directedness and Cooperativeness, compared with the control group. Conclusions: There were significant correlations between ADHD symptoms and Novelty Seeking. Current findings suggest that Novelty Seeking and ADHD share biogenetic backgrounds.

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 Witelsons 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.

The Relationship between the Biogenetic Temperament and Character and Psychopathology in Adolescents

Background: This study was conducted to investigate the relationship between patterns of temperament and character and self-reported psychopathology in adolescents from the community. Sampling and Methods: The Junior Temperament and Character Inventory (JTCI) and Youth Self-Report (YSR) instruments were administered to 623 Korean middle school students (boys/girls = 331/292; age = 13.3 ± 0.9 years old). Multiple linear regression analyses were used to evaluate the relationship between temperament and character based on Cloninger’s biogenetic theory of personality and youth psychopathology of internalizing and externalizing problems. Results: Internalizing problems of the YSR (withdrawn, somatic complaint and anxious/depressed scales) were significantly related to high Harm Avoidance and low Reward Dependence (JTCI temperament) and low Self-Directedness and high Self-Transcendence (JTCI character). Externalizing problems of the YSR (delinquency and aggression) were significantly associated with high Novelty Seeking and high Harm Avoidance (JTCI temperament) and low Self-Directedness, low Cooperativeness and high Self-Transcendence (JTCI character).Conclusions: Findings of the current study suggest that specific patterns of temperament and character potentially influence adolescents’ psychopathology in the community.

Fractional anisotropy-based divisions of midsagittal corpus callosum.

The authors first divided the midsagittal corpus callosum of 22 healthy volunteers using three different subdivision methods: Witelsons geometric subdivision, boundary model-based subdivision, and medial model-based subdivision. Next, subdivisions of the corpus callosum were clustered on the basis of homogeneity of the fractional anisotropy values as produced from diffusion tensor images. Nine subregions of corpus callosum, similar in location and size, were successfully clustered when medial model-based or boundary model-based subdivisions were applied. These nine subregions of the corpus callosum were different from the seven subregions defined by Witelsons geometric subdivision, especially at the anterior and posterior tips of the corpus callosum. Our method of corpus callosum division can be potentially utilized to assess structural changes in the midsagittal corpus callosum.