Associations between urinary cotinine and symptoms of attention deficit/hyperactivity disorder and autism spectrum disorder.

BACKGROUND: The present study investigated associations between urinary cotinine levels as a biomarker of secondhand smoke exposure and symptoms of attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). METHODS: A total of 520 child participants (200 with ADHD, 67 with ASD, and 253 normal control subjects) were assessed using the Korean version of the ADHD rating scale (K-ARS), Autism spectrum screening questionnaire (ASSQ), and Behavioral Assessment System for Children, second edition (BASC-2). The Korean version of the computer-based continuous performance test was used to assess cognitive function. Urinary cotinine was evaluated as a biomarker of secondhand smoke exposure. RESULTS: Urinary cotinine levels were significantly and positively associated with K-ARS score (B = 4.00, p < 0.001), ASSQ score (B = 1.71, p = 0.030), the behavioral problem subscales of the BASC-2 (B = 1.68-3.52, p < 0.001-0.045), and omission and commission errors in the continuous performance test (B = 6.21-8.42, p < 0.001-0.019). Urinary cotinine levels were also associated with the increased odds ratio of ADHD (OR = 1.55, 95% CI 1.05-2.30, p = 0.028) and ASD (OR = 1.89, 95% CI 1.12-3.21, p = 0.018). CONCLUSION: Urinary cotinine levels were associated with lower behavioral adaptation and cognitive function and increased odds ratios of ADHD and ASD, indicating a negative effect of secondhand smoke exposure on the symptomatic manifestation of ADHD and ASD.

Associations between attention-deficit/hyperactivity disorder symptoms and dietary habits in elementary school children.

OBJECTIVE: The aim of the present study was to investigate the associations between dietary habits and attention deficit/hyperactivity disorder (ADHD) symptoms in elementary school children. METHODS: The parents of 16,831 participating children assessed the ADHD symptoms of their children by responding to the Korean version of the ADHD rating scale (K-ARS). Parents also responded to the food habit questionnaire, which consists of 8 items regarding the eating pace, the frequency of overeating, and patterns of eating six types of food: fast food, soft drinks, instant noodles, fruit and vegetables, and milk. RESULTS: K-ARS scores were positively associated with higher consumption of foods categorized as unhealthy, including fast food, soft drinks, and instant noodles, and negatively associated with higher consumption of fruit and vegetables categorized as healthy foods. K-ARS scores were also higher in the groups who overate more frequently and ate faster or slower compared to other family members. CONCLUSION: Our findings may provide useful clinical information for dietary interventions in children with ADHD.

Secondhand Smoke Exposure and Low Blood Lead Levels in Association With Attention-Deficit Hyperactivity Disorder and Its Symptom Domain in Children: A Community-Based Case-Control Study.

AIM: Secondhand smoke (SHS) is a major indoor pollutant. We examined the possible association between exposure to both SHS and low levels of lead and attention-deficit-hyperactivity disorder (ADHD) and its symptom domain in children. METHODS: This case-control study was based on the results of a community survey using the ADHD rating scale conducted in 49 elementary schools. Both cases and control subjects were confirmed by a child psychiatrist. Each case was matched with one control subject according to gender, school, and grade in school. Using a multivariate conditional logistic regression model, we analyzed 214 case-control pairs of children who ranged in age from 6 to 10 years. Urine and blood levels of cotinine and of lead were determined, and information pertaining to SHS exposure was obtained by means of a questionnaire. RESULTS: Exposure to low levels of lead (geometric mean = 1.65 µg/dL) was related to ADHD, particularly inattention (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.07-2.59), whereas SHS exposure was associated mainly with hyperactivity/impulsivity (OR = 3.85, 95% CI = 1.55-9.56). In the pathway from blood lead to hyperactivity/impulsivity, children's SHS exposure mediated and indirectly accounted for about 73% of this relationship. The combined exposure to lead and SHS synergistically increased the risk of ADHD, evident as both inattention and hyperactivity/impulsivity. CONCLUSION: SHS, which is associated with hyperactivity/impulsivity in particular, combined with exposure to low blood levels of lead synergistically increased the risk of ADHD. Therefore, the exposure of children to both SHS and lead needs to be reduced. IMPLICATIONS: Although exposure to low levels of lead has been shown to be associated with ADHD, there is little evidence of symptom domain specificity. In our study, low blood lead levels were related to inattention. In addition, prenatal or postnatal exposure to SHS increased the risk of ADHD, particularly hyperactivity/impulsivity. Combined exposure to lead and SHS synergistically increased the risk for both these ADHD symptom domains. To protect children from environmental risk factors related to ADHD, it is necessary to further reduce children's exposure to SHS and lead, even in those with low blood lead levels.

Prevalence of Attention-Deficit/Hyperactivity Disorder and its Comorbidity among Korean Children in a Community Population.

The aim of this study was to determine the prevalence of attention deficit hyperactivity disorders (ADHD) in children according to socio-demographic factors and the distribution of ADHD subtypes in a community in Korea. A screening survey using the Korean version of ADHD Rating Scale (K-ARS) was conducted between 2007 and 2008, and clinical interviews by a pediatric psychiatrist were performed for selected children between 2009 and 2010. A total of 49,573 elementary school students, between ages of 7 and 12, constituted the target population, among which 38,365 students (77.2%) and respective parents gave consent to participate. Of the participants, 200 screened children were clinically examined to confirm the diagnosis of ADHD. We estimated the prevalence of ADHD and its comorbidity in the population, after adjusting for nonresponse and nonparticipation. The prevalence of ADHD was 11.7% in boys and 5.2% in girls, with an overall prevalence of 8.5%. The combined type of inattentive and hyperactive was the most frequent at 4.7% of the whole population. Children were more likely to have ADHD if their parents were separated and had less education. Most commonly combined comorbidity was autism spectrum disorder (ASD) (10.1%). The prevalence of ADHD in the school-aged population is an essential information for improving the quality of public health mental services for evaluation and treatment of ADHD.

The associations between ADHD and asthma in Korean children.

BACKGROUND: The aim of this study was to investigate the associations between attention deficit hyperactivity disorder (ADHD), the most common neuropsychiatric disorder in school children, and childhood allergic disease by evaluating their respective prevalence. METHODS: Subjects were comprised of first and second grade students in twenty two elementary schools in a city in the Republic of Korea. The mode of measurement for ADHD was based on DSM-IV from clinical interviews conducted by child psychiatrists. Along with the diagnostic interviews, we also used the epidemiological questionnaires, Computerized Attention Deficit-Hyperactivity Disorder Diagnostic System, the abbreviated Conner's Parent Rating Scale (CPRS), and DuPaul's ADHD Rating Scales. Allergic conditions, such as asthma, have been separately evaluated based on the questionnaire items whose validity and reliability were proved by the International Study of Asthma and Allergies in Children (ISAAC). All questionnaires were completed by the subjects' parents. RESULTS: The lifetime prevalence rate of asthma in ADHD patients was 36.6%, compared to a prevalence of 24.3% in control subjects. The lifetime prevalence rate of allergic rhinitis in ADHD patients was 59.0%, compared to a prevalence of 47.0% in control subjects. Statistically significant difference has been found between the two groups. In the logistic regression model of the ADHD and the control group, the relative risk of asthma was 1.60 times higher (confidence interval 1.301-1.964), the relative risk of allergic rhinitis was 1.38 times higher (confidence interval 1.124-1.681), which showed statistical significance. CONCLUSIONS: The findings of this study suggest significant association between ADHD and childhood asthma and allergic rhinitis. Therefore, appropriate evaluation and treatment are needed for asthmatic children with attention-deficit symptoms, or allergic rhinitis with ADHD. Besides, further research is needed to determine the etiological approach towards ADHD, asthma, and allergic rhinitis.

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

OBJECTIVES: 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. METHODS: This randomized, 24-week, double-blind, placebo-controlled multicenter study enrolled patients from 23 centers in Korea. Patients with bipolar I disorder who had manic or mixed episode entered a 6-week open-label stabilization phase. After meeting stabilization criteria, 83 patients were randomly assigned to placebo + divalproex or aripiprazole + divalproex treatment group for the 24-week, double-blind maintenance phase. RESULTS: During the 6-month double-blind treatment, the time to relapse of any mood episode in the aripiprazole group was longer than the placebo group, but the difference did not reach statistical significance (p = 0.098). After controlling for mean divalproex level, the time to depressive episode relapse in the aripiprazole group was longer than those in the placebo group (p = 0.029). Weight gain (≥ 7% increase) occurred in 22.5% aripiprazole group and 18.6% placebo group (p = 0.787). CONCLUSIONS: In this study, relapse of mood episode occurred fewer and later for aripiprazole with divalproex treatment than divalproex monotherapy, but the differences were not statistically significant.

Prenatal exposure to paternal smoking and likelihood for autism spectrum disorder.

LAY ABSTRACT: What is Already Known about This Subject: Genetics, (including de novo mutations), environmental factors (including toxic exposures), and their interactions impact autism spectrum disorder etiology. Paternal smoking is a candidate risk for autism spectrum disorder due to biological plausibility, high prevalence, and potential intervention.What This Study Adds: This original study and its replication confirms that paternal factors can substantially contribute to autism spectrum disorder risk for their offspring. It specifically indicates that paternal smoking both before and during pregnancy contributes significantly to autism spectrum disorder risk.Implications for practice, research, or policy: Smoking prevention, especially in pregnancy planning, may decrease autism spectrum disorder risk in offspring.

Associations among High Risk for Sleep-disordered Breathing, Related Risk Factors, and Attention Deficit/Hyperactivity Symptoms in Elementary School Children.

OBJECTIVE: : Habitual snoring is a common problem in children. We evaluated the association between a high risk for sleep-disordered breathing and attention deficit/hyperactivity symptoms. METHODS: Parents of 13,560 children aged 6 to 12 years responded to questionnaires including items on habitual snoring and the Korean attention deficit/hyperactivity disorder rating scale. The snoring score comprised the number of "yes" responses to habitual-snoring items, and a high risk for sleep-disordered breathing was defined as a snoring score ≥ 2. RESULTS: The odds ratio (OR) of a high risk for sleep-disordered breathing was significantly higher in boys (OR = 1.47; p < 0.001), overweight children (OR = 2.20; p < 0.001), and children with current secondhand-smoking exposure (OR = 1.38; p < 0.001). The Korean attention deficit/hyperactivity disorder rating scale score increased significantly with the snoring score (0 vs. 1, B = 1.56, p < 0.001; 0 vs. 2, B = 2.44, p < 0.001; 0 vs. 3, B = 2.48, p < 0.001; 0 vs. 4, B = 3.95; p < 0.001). CONCLUSION: Our study confirms several risk factors of sleep-disordered breathing, namely male sex, overweight, and exposure to tobacco smoking, and found a positive association between habitual snoring and attention deficit/hyperactivity symptoms.

Associations between Exposure to Bisphenol A and Behavioral and Cognitive Function in Children with Attention-deficit/Hyperactivity Disorder: A Case-control Study.

OBJECTIVE: Bisphenol A (BPA) is a widely produced synthetic chemical used to manufacture polycarbonate plastics and epoxy resins. We aimed to investigate the association between exposure to BPA and behavioral and cognitive function in children with attention-deficit/hyperactivity disorder (ADHD) and healthy controls. METHODS: The study included 444 children aged from 6 to 10 years. The ADHD and control groups included 195 and 249 children, respectively. BPA levels were assessed via urinalysis, while behavior was assessed using the Korean version of the ADHD Rating Scale (K-ARS) and the Behavior Assessment System for Children (BASC-2). Cognitive function was assessed using the Continuous Performance Test (i.e., ADHD Diagnostic System [ADS]). Participants were categorized into tertile groups based on urinary BPA concentration. RESULTS: Scores on the K-ARS and the hyperactivity, aggression, anxiety, and depression subscales of the BASC-2 were significantly different among tertile groups for urinary BPA levels. Scores on visual omission error, commission error, response time variability, and auditory commission error of the ADS were significantly different among three BPA groups. Subgroup analysis revealed that these differences of behavior and cognition among three BPA groups were observed in only boys and normal controls. CONCLUSION: Exposure to BPA was associated with unfavorable behavioral and cognitive outcomes. Our study extends the findings of previous studies regarding the association between BPA exposure and behavior/cognitive function by including children with ADHD. Further studies are required to determine the mechanisms underlying sex- and group-based differences in these associations.

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.

Attention-Deficit/Hyperactivity Disorder Symptom Characteristics in Korean Elementary School Children: Comparison with US Population.

OBJECTIVE: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in elementary school children. The present study investigated the characteristics of ADHD in Korean elementary school children using the Korean version of the ADHD Rating Scale (K-ARS). The data was compared with those obtained from a comparable American population. METHODS: Participants included 29,914 elementary school children, aged 6-12 years, from a medium-sized city. The parents completed the home version of the K-ARS. The total and subscale-specific normative data and sex- and age-related mean score differences were analyzed. These data were compared with those obtained from the American population using independent t-tests. RESULTS: Mean total and subscale K-ARS scores were significantly higher among boys (vs. girls) and younger children aged equal to or less than 8 years old (vs. older children). Mean scores on the hyperactivity-impulsivity subscale were lower than those of American children, but similar to another Korean sample. CONCLUSION: Our data characterized ADHD symptoms in Korean children. However, further studies are needed to identify the cultural differences underlying ratings of ADHD symptom severity.

How Does Low Socioeconomic Status Increase Blood Lead Levelsin KoreanChildren?

Although studies have shown that a low socioeconomic status (SES) is associated with high blood lead levels (BLLs) in children, the mechanism underlying this observation is not well known. To determine how SES influences BLLs via environmental factors in Korean children, we conducted a population-based cross-sectional study of 4744 children aged 5⁻13 years. Questionnaires on sociodemographic information, environmental factors, and food consumption were administered to the children's parents. BLLs in the study subjects were measured.The complete set of hypothesized associations was assessed using regression analysis and structural equation modeling. SES was associated with high BLLs. The total effects of nutritional factors, lead in the air and total length of nearby roads, and agriculture on BLLs were -0.062 (p < 0.001), 0.068 (p = 0.005), and 0.038 (p = 0.035), respectively. The direct effects of playing outdoors and SES on BLLs were 0.113 (p < 0.001) and -0.111 (p < 0.001), respectively. Although playing outdoors had a greater direct effect on BLLs than did SES, the total effect of SES (standardized ß = -0.132, p < 0.001) was greater than that of other sources owing to indirect effects (ß = -0.020, p = 0.004). A low SES was a major risk factor for elevated BLLs via environmental factors.

The Symptom Trajectory of Attention-Deficit Hyperactivity Disorder in Korean School-Age Children.

OBJECTIVE: We aimed to investigate symptom trajectory of attention-deficit hyperactivity disorder (ADHD) in Korean school-age children. METHODS: Four hundred fifty six elementary school children were enrolled when they were in 1st grade and assessed once per year until 4th grade. Symptom severity was assessed by parents using the Korean version of the ADHD rating scale (K-ARS). High-risk was defined as a K-ARS score >18; 377, 325, and 284 children participated in the subsequent assessments. Symptom trajectory was analyzed using a mixed-model approach consistent with the longitudinal nature of the present study including missing data. RESULTS: K-ARS scores demonstrated significant main effects of time (F=35.33; p<0.001), sex (F=20.77; p<0.001), and first-year high-risk group (F=240.90; p<0.001). It also demonstrated a significant time×first-year high-risk group interaction effect (F=38.14; p<0.001), but not a time×sex interaction effect. CONCLUSION: K-ARS scores demonstrated a tendency to decline with aging. Individuals in the high-risk group demonstrated earlier declining tendency than those in the non-high risk group. Although total K-ARS scores differed significantly between the sexes at all assessments, the declining pattern between both sexes did not differ significantly. Further studies including larger sample sizes, diagnostic interviews, and complete data sets are needed to confirm findings of the present study.

The effects of postnatal phthalate exposure on the development of auditory temporal processing in rats.

OBJECTIVE: The central auditory pathway is known to continue its development during the postnatal critical periods and is shaped by experience and sensory inputs. Phthalate, a known neurotoxic material, has been reported to be associated with attention deficits in children, impacting many infant neurobehaviors. The objective of this study was to investigate the potential effects of neonatal phthalate exposure on the development of auditory temporal processing. METHODS: Neonatal Sprague-Dawley rats were randomly assigned into two groups: The phthalate group (n = 6), and the control group (n = 6). Phthalate was given once per day from postnatal day 8 (P8) to P28. Upon completion, at P28, the Auditory Brainstem Response (ABR) and Gap Prepulse Inhibition of Acoustic Startle response (GPIAS) at each gap duration (2, 5, 10, 20, 50 and 80 ms) were measured, and gap detection threshold (GDT) was calculated. These outcomes were compared between the two groups. RESULTS: Hearing thresholds by ABR showed no significant differences at all frequencies between the two groups. Regarding GPIAS, no significant difference was observed, except at a gap duration of 20 ms (p = 0.037). The mean GDT of the phthalate group (44.0 ms) was higher than that of the control group (20.0 ms), but without statistical significance (p = 0.065). Moreover, the phthalate group tended to demonstrate more of a scattered distribution in the GDT group than the in the control group. CONCLUSION: Neonatal phthalate exposure may disrupt the development of auditory temporal processing in rats.

The social responsiveness scale in relation to DSM IV and DSM5 ASD in Korean children.

The Social Responsiveness Scale (SRS) is an autism rating scales in widespread use, with over 20 official foreign language translations. It has proven highly feasible for quantitative ascertainment of autistic social impairment in public health settings, however, little is known about the validity of the reinforcement in Asia populations or in references to DSM5. The current study aims to evaluate psychometric properties and cross-cultural aspects of the SRS-Korean version (K-SRS).The study subjects were ascertained from three samples: a general sample from 3 regular education elementary schools (n=790), a clinical sample (n=154) of 6-12-year-olds from four psychiatric clinics, and an epidemiological sample of children with ASD, diagnosed using both DSM IV PDD, DSM5 ASD and SCD criteria (n=151). Their parents completed the K-SRS and the Autism Spectrum Screening Questionnaire(ASSQ). Descriptive statistics, correlation analyses and principal components analysis (PCA) were performed on the total population. Mean total scores on the K-SRS differed significantly between the three samples. ASSQ scores were significantly correlated with the K-SRS T-scores. PCA suggested a one-factor solution for the total population.Our results indicate that the K-SRS exhibits adequate reliability and validity for measuring ASD symptoms in Korean children with DSM IV PDD and DSM5 ASD. Our findings further suggest that it is difficult to distinguish SCD from other child psychiatric conditions using the K-SRS.This is the first study to examine the relationship between the SRS subscales and DSM5-based clinical diagnoses. This study provides cross-cultural confirmation of the factor structure for ASD symptoms and traits measured by the SRS. Autism Res 2016, 9: 970-980. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Association between BDNF gene polymorphisms and attention deficit hyperactivity disorder in Korean children.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a common childhood neuropsychiatric disorder characterized by behavioral problems such as attention deficit, hyperactivity, and impulsivity. The brain-derived neurotrophic factor (BDNF) is the most abundant neurotrophin in the brain. AIMS: The aim of the present study was to investigate the association between the genotype and alleles for the BDNF gene in Korean children with ADHD. METHODS: The sample consisted of 180 ADHD children and 159 control children. We diagnosed ADHD according to the DSM-IV. ADHD symptoms were evaluated with Conners' Parent Rating Scales and Dupaul Parent ADHD Rating Scales. Blood samples were taken from the 339 subjects, DNA was extracted from blood lymphocytes, and polymerase chain reaction was performed for BDNF rs6265, rs11030101, rs10835210, rs7103873, and rs2030324 polymorphisms. Alleles and genotype frequencies were compared using the Chi-square test. We compared the allele and genotype frequencies of the BDNF gene polymorphism in the ADHD and control groups. RESULTS: This study showed that there was a significant correlation among the allele frequencies of the rs11030101 and rs10835210 single nucleotide polymorphisms (SNPs) (odds ratio=0.61, 95% confidence interval=0.39-0.96, p=0.034), but the final conclusions are not definite. Follow-up studies with larger patient or pure subgroups are expected. These results suggest that the BDNF allelic structure may impact ADHD symptoms.

The effects of prenatal exposure to alcohol and environmental tobacco smoke on risk for ADHD: a large population-based study.

Attention deficit hyperactivity disorder (ADHD) is caused by the interaction of genetic and environmental factors. The objective of this study was to examine the effects of prenatal exposure to alcohol and environmental tobacco smoke (ETS). Among the 30,552 parents who responded to a survey, the answers of 19,940 who replied to questions on prenatal exposure to ETS, alcohol consumption, and completed the DuPaul Rating Scale were analyzed. Results revealed that risk of ADHD significantly increased as a result of exposure to alcohol by 1.55 times (95% CI 1.33-1.82), maternal smoking during pregnancy by 2.64 times (95% CI 1.45-4.80), and paternal smoking during pregnancy by 1.17 times (95% CI 1.98-1.39). When the subjects whose mothers did not smoke during pregnancy were divided into 4 groups, the prevalence was 1.16 times higher (95% CI 1.02-1.33) in the group exposed to ETS but not alcohol, 1.19 times higher (95% CI 0.91-1.57) in the group exposed to alcohol but not ETS, and 1.58 times higher (95% CI 1.31-1.91) in the group exposed to ETS and alcohol. The differences between the groups were statistically significantly (P<0.0001). This result shows that simultaneous exposure to ETS and alcohol during pregnancy increases the risk of ADHD.

No Association between the Response to Methylphenidate and DRD4 Gene Polymorphism in Korean Attention Deficit Hyperactivity Disorder: A Case Control Study.

OBJECTIVE: Recently the relationship between alleles frequency distribution, drug response and the attention deficit hyperactivity disorder (ADHD), has been actively researched. We investigated the association between the genetic type, alleles and drug response for the dopamine receptor D4 (DRD4) gene in ADHD patients in Korea. METHODS: One hundred fourteen patients diagnosed with ADHD according to the the Diagnostic and Statistical Manual of Mental Disorders version IV (DSM-IV) diagnostic criteria were selected for the study. The clinical features of patients were confirmed by Korean version of Conners' parent rating scale, Attention deficit Diagnostic System, Korean version of Spielberger state-trait anxiety scale. Blood samples were taken from the 198 subjects. DNA was extracted from blood lymphocytes, PCR was performed for DRD4 Polymorphism. Alleles, genotype frequencies, the Clinical Global Impression (CGI) improvement score were compared using the chi-square test. Korean ADHD Rating Scale (K-ARS) and CGI severity scores were compared using the t-test. RESULTS: In comparing the ADHD with 4/4 repeats group and without the ADHD with 4/4 repeats group, no significant difference was seen between the DRD4 genetic type, alleles distribution, and CGI drug response. CONCLUSION: As a result, it is viewed that there is no relationship between ADHD and DRD4, but final decision is indefinite. Follow up studies with larger patient or pure subgroups are expected.

Association between HTR1A gene polymorphisms and attention deficit hyperactivity disorder in Korean children.

Attention deficit hyperactivity disorder (ADHD) is a common disorder of the school age population. ADHD has been shown to be familial, and genetic studies estimate its heritability at 80%-90%. The aim of the present study was to investigate the association between the genetic type and alleles for the HTR1A gene in Korean children with ADHD. The sample consisted of 142 ADHD children and 139 control children. We diagnosed ADHD according to the Diagnostic and Statistical Manual of Mental Disorders-4th edition. ADHD symptoms were evaluated with Conners' Parent Rating Scales and Dupaul Parent ADHD Rating Scales. Blood samples were taken from the 281 subjects, DNA was extracted from blood lymphocytes, and polymerase chain reaction was performed for HTR1A polymorphism. Alleles and genotype frequencies were compared using the chi-square test. We compared the allele and genotype frequencies of HTR1A gene polymorphism in the ADHD and control groups. This study showed that there was a significant correlation among the frequencies of the rs10042486 (OR=1.55, 95% CI=1.02-2.30, p=0.041), rs1423691(OR=1.55, 95% CI=1.02-2.30, p=0.041),and rs878567(OR=1.60, 95% CI=1.06-2.43, p=0.027) alleles of HTR1A, but the final conclusions are not definite. Follow-up studies with larger patient or pure subgroups are expected. These results suggested that HTR1A might be related to ADHD symptoms.

Epidemiological characteristics of mobile phone ownership and use in korean children and adolescents.

OBJECTIVES: As public concern on possible harmful effects of mobile phone in children has been raised, information of epidemiological characteristics of mobile phone use in children and adolescents will be essential for public health policy. METHODS: Using three databases (n=21,693) collected from 2008 to 2011, we examined characteristics of mobile phone ownership and use, and socioeconomic positions (SEP) in Korean children and adolescents. RESULTS: The ownership rate and the amount of mobile phone use were higher in females than males, in higher school grades than lower grades, and at 2011 than 2008. The average age of first mobile phone ownership was shown to decrease from 12.5 years in currently high school students to 8.4 years in currently elementary school students at 2011. More than 90% of children in the 5th grade owned a mobile phone. More children owned a mobile phone in lower SEP communities than in higher SEP. Children with parents educated less than those with parents educated more were more likely to own and use mobile phone. CONCLUSIONS: Considering the epidemiological characteristics of mobile phone use, precautionary measures to prevent unnecessary exposure to mobile phones are needed in children and adolescents.