Chul Na

Association of aggressive behavior in Korean male schizophrenic patients with polymorphisms in the serotonin transporter promoter and catecholamine-O-methyltransferase genes

The incidence of aggressive behavior in patients with schizophrenia is higher than in the general population. Among particular gene polymorphisms posited to be involved in psychiatric disorders, the catecholamine-O-methyltransferase (COMT) and serotonin transporter (5-HTTPR) genes have been the focus of recent research on aggression. In this study, we hypothesized that both the COMT and the 5-HTTPR genotypes may be dependent on and related to aggression in Korean patients with schizophrenia. The subjects were 168 unrelated male schizophrenic patients diagnosed according to DSM-IV. Among two psychiatric hospital staff and medical university students, 158 unrelated male subjects with no lifetime history of psychiatric disorders were recruited to establish the COMT and 5-HTTPR genotype distribution in the general population. All episodes of aggression from the last discharge to readmission were rated. The Total Overt Aggression Scale (OAS) score (sum of the scores of all episodes of aggression), highest OAS score (highest individual episode score, 0-16), OAS category, and OAS category score (mean score within each category) were recorded. There were statistically significant effects of COMT genotype on the mean OAS 4 (physical aggression against other people) score and the highest OAS score. The most predictive was the OAS 4 score. There was a statistically significant effect of 5-HTTPR genotype on mean total score. Thus, the COMT gene is associated with the severity of aggression and with physical aggression against other people, whereas the 5-HTTPR gene is associated with the summary score of all episodes of aggression.

Effect of genetic polymorphisms on smoking cessation: a trial of bupropion in Korean male smokers

Background Even though bupropion is first-line pharmacological agent for smoking cessation, not all the smokers successfully quit smoking by bupropion. It means other factors like genetic predisposition could contribute to the therapeutic outcome. Objectives The aim of this study is to elucidate the question of whether the abstinence rates by bupropion trial would be different depending on the genotypes. Methods Six candidate genes, thought to be involved in the interaction of nicotine and bupropion (for example, the dopamine receptor type 2, dopamine transporter, norepinephrine transporter, serotonin transporter, catecholamine-O-methyltransferase), and the clinical outcomes of smoking behavior were investigated. The participants were 225 male smokers to whom 150 mg of bupropion SR was administered for 4 weeks. The abstinence rates of specific genotypes were also compared. Main results The results are as follows: (a) the frequencies of the A1/A2 genotype of the dopamine receptor type 2 TaqI A gene and SLC6A3-9 genotype of the dopamine transporter 1 gene were higher in the nonabstinence group than in the abstinence group (χ2=20.40, P<0.01 for A1/A2, χ2=7.76, P=0.01 for SLC6A3-9). The frequencies of the COMTH/COMTH and A/G genotypes of the norepinephrine transporter gene were higher in the abstinence group than in the nonabstinence group (χ2=8.12,P=0.02 for COMTH/COMTH, χ2=3.04, P<0.01 for A/G). (b) Participants having specific genotypes such as homozygotes (A1/A1 or A2/A2) of DRD2 TaqI A, COMTH/COMTH, AG of NET-8, and LL of 5-HTTLPR showed a higher abstinence rate than the other participants. Conclusions It can be concluded that genetic diversity might determine the effects of bupropion on smoking cessation.

Attention Deficit Hyperactivity Disorder Like Behavioral Problems and Parenting Stress in Pediatric Allergic Rhinitis

Objective Previous studies have reported comorbidity of attention deficit and hyperactivity disorder (ADHD) and allergic diseases. The current study investigated ADHD like behavioral symptoms and parenting stress in pediatric allergic rhinitis. Methods Eighty-seven children (6-13 years old) with allergic rhinitis and 73 age- and sex-matched children of control group were recruited. Diagnosis and severity assessments of allergic rhinitis were determined by a pediatric allergist. The Parenting Stress Index-Short Form (PSI-SF), ADHD Rating Scale (ARS), and Child Behavior Checklist (CBCL) were completed by their mothers. Results In the allergic rhinitis group, the total PSI-SF score (p<0.01), ARS score (p<0.01), the subscale scores of the CBCL including somatization, attentional problems and emotional instability (p=0.01; p<0.01; p<0.01) and prevalence of ADHD (p=0.03) were significantly higher than those of the control group. Among mothers of children with allergic rhinitis, those of children with comorbid ADHD demonstrated significantly higher parenting stress than those without comorbid ADHD (p<0.01). Parenting stress was correlated with severity of childs allergic symptoms and the ARS total score (beta=0.50, p<0.01; beta=0.39, p<0.01). There was a significant correlation between allergic symptom severity and the ARS total score (B=8.4, SD=2.5, t=3.3, p<0.01). Conclusion This study demonstrated that ADHD symptoms were common in children with allergic rhinitis, and this factor increased parenting stress and disrupted the parent-child relationship. Routine evaluation and early management of ADHD symptoms in pediatric allergic rhinitis may benefit families of children with allergic rhinitis.

Alcohol urge and plasma β-endorphin change after alcohol challenge with naltrexone pretreatment in social drinkers

The authors have investigated the effect of naltrexone (NTX) on lowering the urge of alcohol drinking and the action mechanism of NTX. Fifteen healthy male social drinkers voluntarily participated. The experimental method was a double-blind, placebo-controlled cross-over design. To eliminate NTX effect, 1 week washout cross-over interval was taken. Subjects ingested NTX, 50 mg/day, or placebo for 1 week. Then, the alcohol (0.5 ml/kg) challenge test was done in the evening. Blood samples were taken immediately before drinking, at 20 min and at 60 min after alcohol drinking. Plasma beta-endorphin, plasma ACTH and serum cortisol levels were checked. Subjects completed self-report questionnaires such as the visual analog scales of drink urge and the alcohol sensation scales at regular intervals. In the case of NTX pretreatment, the subjects reported significantly (P=.013) less urge to drink alcohol on the self-reporting urge scales, especially at postdrinking 20 min and 60 min than placebo pretreatment. After alcohol challenge, the subjects reported significantly more dizziness (P=.015) in the case of NTX pretreatment, and reported less mood elevation trend, though not significant (P=.052). Basal plasma beta-endorphin levels were not different, but in the case of NTX pretreatment, the increasing degree of plasma beta-endorphin during 20 min after alcohol challenge was significantly (P=.039) higher than with placebo pretreatment. This results show that the NTX reduced the urge to drink alcohol with the mechanism of partially blocking the opioid positive reward system and partially mimicking the alcohol effect.

Desynchronization of Theta-Phase Gamma-Amplitude Coupling during a Mental Arithmetic Task in Children with Attention Deficit/Hyperactivity Disorder

Introduction Theta-phase gamma-amplitude coupling (TGC) measurement has recently received attention as a feasible method of assessing brain functions such as neuronal interactions. The purpose of this electroencephalographic (EEG) study is to understand the mechanisms underlying the deficits in attentional control in children with attention deficit/hyperactivity disorder (ADHD) by comparing the power spectra and TGC at rest and during a mental arithmetic task. Methods Nineteen-channel EEGs were recorded from 97 volunteers (including 53 subjects with ADHD) from a camp for hyperactive children under two conditions (rest and task performance). The EEG power spectra and the TGC data were analyzed. Correlation analyses between the Intermediate Visual and Auditory (IVA) continuous performance test (CPT) scores and EEG parameters were performed. Results No significant difference in the power spectra was detected between the groups at rest and during task performance. However, TGC was reduced during the arithmetic task in the ADHD group compared with the normal group (F = 16.70, p < 0.001). The TGC values positively correlated with the IVA CPT scores but negatively correlated with theta power. Conclusions Our findings suggest that desynchronization of TGC occurred during the arithmetic task in ADHD children. TGC in ADHD children is expected to serve as a promising neurophysiological marker of network deactivation during attention-demanding tasks.