Early changes of serum BDNF and SSRI response in adolescents with major depressive disorder

BACKGROUND

Recent evidence suggests that brain-derived neurotrophic factor (BDNF) levels and their early changes may predict antidepressant response in adults with major depressive disorder (MDD). However, in adolescents, BDNF levels in depression and their changes during antidepressant treatment are relatively unknown. We aimed to investigate whether pre-treatment BDNF levels and their early changes predict antidepressant response in depressed adolescents.

METHODS

The study included 83 MDD adolescents and 52 healthy controls aged 12 to 17 years. All depressed adolescents were treated with escitalopram in an 8 week, open-label trial. Depression severity and serum BDNF level at baseline, and weeks 2 and 8 were measured with the Children's Depression Rating Scale-Revised (CDRS-R) and ELISA, respectively.

RESULTS

Responders showed a significant decrease in BDNF levels at week 2 but non-responders and healthy controls had no changes in BDNF levels at week 2. The early decrease (baseline - week 2) of BDNF levels predicted SSRI response with moderate sensitivity and specificity. Logistic regression analysis revealed that early BDNF decrease predicted SSRI response at week 8 after controlling for other demographic and clinical variables.

LIMITATIONS

The follow-up duration of the study was limited in 8 weeks. It remains possible that serum BDNF levels would have changed with longer treatment.

CONCLUSIONS

This is the first longitudinal study to investigate the effect of antidepressants on BDNF levels in adolescents with MDD. Our findings suggest that a decrease of serum BDNF levels in early phase of SSRI treatment may be associated later SSRI response in adolescents with MDD.

Psychometric properties and factor structure of the Korean version of the screen for child anxiety related emotional disorders (SCARED)

BACKGROUND

The aim of this study was to examine the psychometric properties of the Korean version of Screen for Child Anxiety Related Emotional Disorders (SCARED) on a sample of Korean youths and to examine the cross-cultural differences in adolescents' anxiety.

METHODS

Our study included 147 adolescents (ages 12-17, 92 girls), 93 with major depressive disorder and 54 as controls. Participants were evaluated using the Kiddie-Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL), SCARED, Child Behavior Checklist (CBCL), Disruptive Behavioral Disorder Scale (DBD) and Attention Deficit Hyperactivity Disorder Rating Scale (ADHD-RS). Pearson's r and Cronbach's α values of the SCARED were calculated, and exploratory factor analysis was conducted.

RESULTS

The Korean SCARED scores were correlated with the total anxiety scores of K-SADS-PL (r = 0.74) and the CBCL anxious/depressed subscale scores (r = 0.35). Results showed a five-factor structure with good internal consistency, in which some items were loaded on different factors compared to previous studies.

CONCLUSIONS

The Korean SCARED demonstrated promising psychometric properties, and could be a valid scale for screening anxiety symptoms in primary care. The fact that different items comprised the factors may reflect the cultural difference between United States and Korea in experiencing anxiety.

Breastfeeding is associated with enhanced learning abilities in school-aged children

OBJECTIVE

The majority of studies on the associations between breastfeeding and cognitive functioning have focused on IQ, with only a few investigating learning skills, and none of the latter adjusting for maternal IQ. We examined the association between breastfeeding and learning abilities in school-aged children using a cross-sectional design.

METHODS

We recruited 868 children, aged 8-11 years and parents completed the Learning Disability Evaluation Scale (LDES). Multivariable linear regression models were used and age, gender, area of residence, annual family income, maternal education, and maternal age at delivery, were included as covariates. Maternal IQ was added to further adjust for the effects of maternal cognitive ability. Path analysis was conducted to investigate the mediation effect of maternal IQ between breastfeeding and learning skills.

RESULTS

Children who were ever-breastfed had higher learning quotient scores on the LDES (p = 0.001) as well as higher scores on subscales related to speaking (p = 0.001), reading (p = 0.005), writing (p = 0.004), spelling (p = 0.003), and mathematical calculation (p = 0.003) than the never-breastfed participants. All of these variables remained significant after adjusting for gestational and socioeconomic factors and for maternal IQ as covariates. The path analysis showed that breastfeeding had both indirect and direct effects on the learning quotient.

CONCLUSIONS

The results suggest that breastfeeding is positively associated with learning skills in school-aged children.

Interactions Between Early Trauma and Catechol-O-Methyltransferase Genes on Inhibitory Deficits in Children With ADHD

OBJECTIVE

To investigate the interaction between childhood trauma exposure with the catechol-O-methyltransferase (COMT) and dopamine receptor D4 (DRD4) polymorphisms in relation to neuropsychological measures in children with ADHD.

METHOD

A cross-sectional examination of early traumatic experiences and the continuous performance test (CPT) were performed in 55 children with ADHD. Participants were also genotyped for the DRD4 exon III 48-bp variable number of tandem repeats (VNTR) polymorphism and the COMT Val¹⁵⁸-Met (rs4680) polymorphism.

RESULTS

There was significant interaction between the effects of the COMT genotype and trauma in commission errors. In participants with ADHD carrying the COMT Val/Val genotype, the group exposed to trauma showed significantly higher commission errors than the non-traumatized group. However, for the participants with other genotypes, no significant differences were found.

CONCLUSION

This study suggests that there exists a genetic influence on the association between childhood trauma and the severity of inhibitory deficits in children with ADHD.

Genetic association analyses of neuregulin 1 gene polymorphism with endopheontype for sociality of Korean autism spectrum disorders family

To determine the genetic association between qualitative and quantitative traits of autism spectrum disorder (ASD) and neuregulin 1 (NRG1)-a schizophrenia candidate gene-we examined six single nucleotide polymorphisms (SNPs) in NRG1 using a family-based association test (FBAT) in Korean families with ASD. rs35753505 and rs6994992 SNPs in NRG1 revealed a statistically significant family-based association with three quantitative traits for sociality.

Child and adolescent psychiatry in the Far East

AIM

Despite the general consensus on the importance of youth mental health, the scarcity of child and adolescent mental health services is prominent all over the world. Child and adolescent psychiatry (CAP) postgraduate training can play a pivotal role in increasing access to youth mental health services. In comparison to Europe and North America, however, little is reported regarding CAP training in the Far East, one of the most dynamic and rapidly developing world regions with a very young population. This paper presents an original study on the current status of academic child and adolescent psychiatry training across the Far East.

METHODS

We collected data from 17 countries in the Far East using an internally distributed questionnaire to the Consortium members invited for this study, consisting of leading academic child and adolescent psychiatrists in each country.

RESULTS

Based on informants' input, we found an overall underdevelopment of CAP postgraduate training systems despite CAP's recognition as a subspecialty in 12 of 17 of the nations or functionally self-governing areas in the Far East. Paucity of official guidelines for CAP training was also evident. All informants reported a need for additional child and adolescent mental health professionals.

CONCLUSION

There seems to be several obstacles to the development of CAP postgraduate training in the Far East, including stigma towards mental health issues and lack of funding. International collaboration is desired to develop evidence-based and culture-tailored CAP training systems.

Environmental lead exposure and attention deficit/hyperactivity disorder symptom domains in a community sample of South Korean school-age children

BACKGROUND

Low-level environmental exposure to lead has been associated with both reduced intelligence and symptoms of attention deficit/hyperactivity disorder (ADHD). However, few studies have estimated the association of lead and intelligence independent of ADHD, and it is not clear from previous studies whether lead is associated with both inattention and impulsivity ADHD symptoms.

OBJECTIVES

We estimated mutually adjusted associations of environmental lead exposure with both intelligence and ADHD symptoms, and associations between lead and specific ADHD-related domains.

METHODS

Blood lead concentrations were measured in a general population of 1,001 children 8-11 years of age. We used multivariable linear regression models to estimate associations of blood lead concentrations with IQ scores, teacher and parent ratings of ADHD symptoms, and measures of inattention and impulsivity. Models were adjusted for demographic variables and other environmental exposures (blood levels of mercury and manganese, urinary concentrations of cotinine, phthalate metabolites, and bisphenol A).

RESULTS

Associations of blood lead with lower IQ and higher impulsivity were robust to adjustment for a variety of covariates. When adjusted for demographic characteristics, other environmental exposures, and ADHD symptoms or IQ, a 10-fold increase in blood lead concentration was associated with lower Full-Scale IQ (-7.23; 95% CI: -13.39, -1.07) and higher parent- and teacher-rated hyperactivity/impulsivity scores (ADHD Rating Scale, 1.99; 95% CI: 0.17, 3.81 and 3.66; 95% CI: 1.18, 6.13, respectively) and commission errors (Continuous Performance Test, 12.27; 95% CI: -0.08, 24.62). Blood lead was not significantly associated with inattention in adjusted models.

CONCLUSIONS

Low-level lead exposure was adversely associated with intelligence in school-age children independent of ADHD, and environmental lead exposure was selectively associated with impulsivity among the clinical features of ADHD.

Clinical characteristics and precipitating factors of adolescent suicide attempters admitted for psychiatric inpatient care in South Korea

OBJECTIVE

We aimed to examine the rates, correlates, methods, and precipitating factors of suicide attempts among adolescent patients admitted for psychiatric inpatient care from 1999 to 2010 in a university hospital in Korea.

METHODS

The subjects consisted of 728 patients who were admitted for psychiatric inpatient care in a university hospital over a 12-year period and who were aged 10-19 years at the time of admission. We retrospectively investigated the information on suicidal behaviors and other clinical information by reviewing the subjects' electronic medical records. Whether these patients had completed their suicide on 31 December 2010 was determined by a link to the database of the National Statistical Office.

RESULTS

Among 728 subjects, 21.7% had suicidal ideation at admission, and 10.7% admitted for suicidal attempts. Female gender, divorced/widowed parents, and the presence of mood disorders were associated with a significantly increased likelihood of suicide attempts. Most common method of suicide attempts was cutting, and most common reason for suicide attempts was relationship problems within the primary support group. A diagnosis of schizophrenia was associated with increased risk of death by suicide after discharge.

CONCLUSION

These results highlight the role of specific psychosocial factor (e.g., relational problems) and psychiatric disorders (e.g., mood disorders) in the suicide attempts of Korean adolescents, and the need for effective prevention strategies for adolescents at risk for suicide.

Di-(2-ethylhexyl) phthalate exposure is negatively correlated with trait anxiety in girls but not with trait anxiety in boys or anxiety-like behavior in male mice

The authors aimed to study the effects of postnatal exposure to phthalate on anxiety-like behavior in mice and anxiety proneness in children. Male Imprinting Control Region (ICR) mice aged 4 weeks were administered 20 to 540 mg/kg of di-(2-ethylhexyl) phthalate (DEHP) or vehicle and assessed in the Open Field Test. A group of 277 children aged 8-11 years (150 males) was recruited from South Korea. A cross-sectional examination of urinary DEHP and dibutylphthalate metabolite concentrations was conducted, and the children were scored on the Trait Anxiety Inventory for Children (TAIC). DEHP metabolite concentrations in the urine were significantly and negatively correlated with TAIC scores in the female population but not in the male population. There were no significant group differences in the percentage of distance moved or time spent in the central area in male mice treated with DEHP or vehicle. Our results suggest a sex-dependent effect of DEHP on anxiety proneness in childhood.

Blood manganese levels in relation to comorbid behavioral and emotional problems in children with attention-deficit/hyperactivity disorder

Patients with attention-deficit/hyperactivity disorder (ADHD) appear to be more vulnerable to the development of other psychiatric disorders than the general population. The proposed neurotoxic mechanisms of manganese involve striatal dopamine neurotransmission, implicated in the pathophysiology of ADHD. We investigated whether the adverse impact of manganese is particularly pronounced in children with ADHD. Blood manganese concentration and diagnosis of ADHD were assessed in a general population of 890 children, aged 8-11 years. The main outcome measure was the Child Behavior Checklist (CBCL). A significant interaction was found between ADHD status and blood manganese level in predicting CBCL total problems score as well as anxiety/depression, social problems, delinquent behavior, aggressive behavior, internalizing problems, and externalizing problems. The directions of the interactions indicated that blood manganese level was more positively correlated with CBCL scores in ADHD children than in the healthy population. In ADHD children, only the fifth quintile of blood manganese concentration was significantly associated with the CBCL total problems score. ADHD children may be more vulnerable than the general school-age population to the neurotoxic effects of manganese exposure, which lead to an elevated risk of developing comorbid mental conditions.

Differential perinatal risk factors in children with attention-deficit/hyperactivity disorder by subtype

We compared the attention-deficit/hyperactivity disorder(ADHD) combined subtype (ADHD-C) to the ADHD inattentive subtype (ADHD-I) in terms of genetic, perinatal, and developmental risk factors as well as clinical and neuropsychological characteristics. A total of 147 children diagnosed with ADHD between the ages of 6 and 15 years participated in this study. The parents of the children completed the structured diagnostic interview, the ADHD Rating Scale-IV, the Children's Behavior Checklist, and structured questionnaires on perinatal risk factors, and the children underwent a neuropsychological test and were genotyped. A total of 502 children without ADHD were recruited from the community as a healthy control group. The ADHD-C children showed more severe externalizing symptoms, showed more deficits in a continuous performance test, and were more likely to have comorbid disorders. Maternal stress during pregnancy, postpartum depression, and changes in the primary caretaker during first 3 years were significantly associated with both ADHD-I and ADHD-C. The ADHD-I group was less likely to have received regular prenatal check-ups and more likely to have had postnatal medical illness than the ADHD-C group. There were no significant differences in the genotype frequencies of the dopamine transporter (DAT1) and the serotonin transporter -linked polymorphic region (5-HTTLPR) polymorphisms between ADHD-I and ADHD-C groups. This study shows that the inattentive subtype of ADHD is different from the combined subtype in many parameters including severity of symptoms, comorbidity, neuropsychological characteristics, and environmental risk factors.

Protective effect of breastfeeding with regard to children's behavioral and cognitive problems

BACKGROUND

Breastfeeding has been associated with a lower risk for behavioral problems in childhood. However, it is uncertain whether these associations are mediated by the mother's or child's IQ. We examined the association between breastfeeding and attention-deficit hyperactivity disorder (ADHD) and other behavioral problems in childhood and assessed the role of the child's IQ and the mother's IQ in generating this association.

FINDINGS

The current study included 874 children (8-11 years) recruited from schools in five Korean cities. Mothers were asked about nursing, and the prevalence of attention-deficit hyperactivity disorder (ADHD) and behavioral problems were compared between children who were breastfed and those who were not breastfed. After adjusting for age, gender, area of residence, and yearly family income, a lack of breastfeeding was associated with increased internalizing, externalizing, and overall behavioral problems as well as the diagnosis of ADHD. These associations weakened but mostly remained significant after adjusting for child's IQ and maternal IQ. In addition, a lack of breastfeeding was associated with low child's IQ and this association weakened, but remained significant even after adjusting for maternal IQ and the diagnosis of ADHD.

CONCLUSIONS

This study suggests that there is a protective effect of breastfeeding on childhood behavioral outcomes with a partial mediation of this effect by the child's IQ, and there is a positive effect of breastfeeding on childhood intelligence with a partial mediation of this effect by the child's attention problem.

The role of the brain-derived neurotrophic factor genotype and parenting in early life in predicting externalizing and internalizing symptoms in children with attention-deficit hyperactivity disorder

BACKGROUND

We aimed to determine whether early parenting is associated with externalizing and internalizing symptoms in children with attention-deficit hyperactivity disorder (ADHD) and whether such an association is affected by the brain-derived neurotrophic factor (BDNF) val66met polymorphism.

METHODS

The participants included 92 patients with ADHD aged 6-15 years. Measures of parenting in early life and externalizing and internalizing symptoms and the genotype of the BDNF Val66Met polymorphism were obtained.

RESULTS

The degree to which the baby's autonomy was allowed was significantly and negatively correlated with the CDI scores in ADHD children (r = -0.38, p = 0.005). After adjusting for the child's gender, the child's age, the family's gross annual income, and the maternal education level, there was a significant interaction for the BDNF genotype and mother's positive feelings about caring in relation to the development of childhood anxiety/depression in ADHD children (F = 2.51, p = 0.011).

CONCLUSIONS

Our results provide evidence of an interaction between the BDNF met allele and early parenting on the development of depression/anxiety symptoms.

Associations between maternal stress during pregnancy and offspring internalizing and externalizing problems in childhood

Background

Maternal psychological health during pregnancy has been associated with offspring psychopathology. However, it is uncertain whether these associations are mediated by the postpartum depression and related child-rearing factors. Therefore, we examined the associations between prenatal and postnatal factors and internalizing and externalizing behavioral problems in childhood, focusing on maternal psychological health in school-aged children in Korea.

Findings

The current study included 1,003 children (580 boys, 423 girls, mean age 9.05 ± 0.70 years, age range 8–11 years) recruited from schools in five Korean cities. Children’s internalizing and externalizing problems were assessed by the Child Behavior Checklist (CBCL). The parents of the children completed structured questionnaires on perinatal factors. Among 1,003 children, 44 had internalizing problems (IP) and 30 had externalizing problems (EP). When comparing children with IP (n = 44) and without IP (n = 959), severe maternal stress during pregnancy (OR3.36, 95% CI 1.80-6.25) and postpartum depression (OR3.19, 95% CI 1.36-7.53) showed a significant association with the IP. When comparing children with EP (n = 30) and without EP (n = 973), low family income (OR2.19, 95% CI 1.05-4.56), unwanted pregnancy (OR2.76, 95% CI 1.28-5.95) and severe maternal stress during pregnancy (OR2.69, 95% CI 1.29-5.61) with the EP. Only maternal stress during pregnancy was significantly associated with the IP after controlling for postpartum depression and with the EP after controlling for family income and unwanted pregnancy.

Conclusion

This study suggests the importance of maternal psychological health during perinatal period on children’s mental health. Further prospective studies in a larger sample are required to confirm our findings.

Different clinical courses of children exposed to a single incident of psychological trauma: a 30-month prospective follow-up study

BACKGROUND

We investigated the distinct longitudinal trajectories of posttraumatic stress symptoms in a sample of 167 children, who witnessed death of two mothers of their schoolmates.

METHODS

The cohort was followed-up at 2 days (T1), 2 months (T2), 6 months (T3), and 30 months (T4) after the traumatic event. The children's posttraumatic stress symptoms (T1-T4), depression (T1, T3 and T4), state anxiety (T1, T3 and T4), and quality of life (T4) were assessed, along with parental stress related to child rearing (T4). Different trajectory patterns of the children's posttraumatic stress symptoms were identified using growth mixture modeling (GMM).

RESULTS

Four different patterns of symptom change were identified, which were consistent with the prototypical model, and were named Recovery (19.9%), Resilience (72.7%), Chronic Dysfunction (1.8%), and Delayed Reactions (5.6%). Significant differences were found in depression and anxiety scores, children's quality of life, and parental rearing stress according to the distinct longitudinal trajectories of posttraumatic stress symptoms.

CONCLUSIONS

The present study suggests that individual differences should be taken into account in the clinical course and outcome of children exposed to psychological trauma. The two most common trajectories were the Resilience and the Recovery types, together suggesting that over 90% of children were evidenced with a favorable 30-month outcome. The latent classes were associated with significant mean differences in depression and anxiety scores, supporting the clinical validity of the distinct trajectories.

Connectomic disturbances in attention-deficit/hyperactivity disorder: a whole-brain tractography analysis

BACKGROUND

Few studies have sought to identify, in a regionally unbiased way, the precise cortical and subcortical regions that are affected by white matter abnormalities in attention-deficit/hyperactivity disorder (ADHD). This study aimed to derive a comprehensive, whole-brain characterization of connectomic disturbances in ADHD.

METHODS

Using diffusion tensor imaging, whole-brain tractography, and an imaging connectomics approach, we characterized altered white matter connectivity in 71 children and adolescents with ADHD compared with 26 healthy control subjects. White matter differences were further delineated between patients with (n = 40) and without (n = 26) the predominantly hyperactive/impulsive subtype of ADHD.

RESULTS

A significant network comprising 25 distinct fiber bundles linking 23 different brain regions spanning frontal, striatal, and cerebellar brain regions showed altered white matter structure in ADHD patients (p < .05, family-wise error-corrected). Moreover, fractional anisotropy in some of these fiber bundles correlated with attentional disturbances. Attention-deficit/hyperactivity disorder subtypes were differentiated by a right-lateralized network (p < .05, family-wise error-corrected) predominantly linking frontal, cingulate, and supplementary motor areas. Fractional anisotropy in this network was also correlated with continuous performance test scores.

CONCLUSIONS

Using an unbiased, whole-brain, data-driven approach, we demonstrated abnormal white matter connectivity in ADHD. The correlations observed with measures of attentional performance underscore the functional importance of these connectomic disturbances for the clinical phenotype of ADHD. A distributed pattern of white matter microstructural integrity separately involving frontal, striatal, and cerebellar brain regions, rather than direct frontostriatal connectivity, appears to be disrupted in children and adolescents with ADHD.

Environmental tobacco smoke exposure and children's intelligence at 8-11 years of age

BACKGROUND

Evidence supporting a link between postnatal environmental tobacco smoke (ETS) exposure and cognitive problems among children is mounting, but inconsistent.

OBJECTIVES

We examined the relationship between ETS exposure, measured using urine cotinine, and IQ scores in Korean school-aged children.

METHODS

The participants were 996 children 8-11 years of age recruited from five administrative regions in South Korea. We performed a cross-sectional analysis of urinary cotinine concentrations and IQ scores obtained using the abbreviated form of a Korean version of the Wechsler Intelligence Scales for Children. Associations were adjusted for potential confounders, and estimates were derived with and without adjustment for mother's Full-Scale IQ (FSIQ) score.

RESULTS

After adjusting for sociodemographic and developmental covariates, urinary cotinine concentrations were inversely associated with FSIQ, Verbal IQ (VIQ), Performance IQ (PIQ), vocabulary, math, and block design scores. Following further adjustment for maternal IQ, only the VIQ scores remained significantly associated with urinary cotinine concentration (B = -0.31; 95% CI: -0.60, -0.03 for a 1-unit increase in natural log-transformed urine cotinine concentration; p = 0.03).

CONCLUSION

Urine cotinine concentrations were inversely associated with children's VIQ scores before and after adjusting for maternal IQ. Further prospective studies with serial measurements of cotinine are needed to confirm our findings.

COMT genotype affects brain white matter pathways in attention-deficit/hyperactivity disorder

Increased dopamine availability may be associated with impaired structural maturation of brain white matter connectivity. This study aimed to derive a comprehensive, whole-brain characterization of large-scale axonal connectivity differences in attention-deficit/hyperactivity disorder (ADHD) associated with catechol-O-methyltransferase gene (COMT) Val158Met polymorphism. Using diffusion tensor imaging, whole-brain tractography, and an imaging connectomics approach, we characterized altered white matter connectivity in youth with ADHD who were COMT Val-homozygous (N = 29) compared with those who were Met-carriers (N = 29). Additionally, we examined whether dopamine transporter gene (DAT1) and dopamine D4 receptor gene (DRD4) polymorphisms were associated with white matter differences. Level of attention was assessed using the continuous performance test before and after an 8-week open-label trial of methylphenidate (MPH). A network of white matter connections linking 18 different brain regions was significantly weakened in youth with ADHD who were COMT Met-carriers compared to those who were Val-homozygous (P < 0.05, family-wise error-corrected). A measure of white matter integrity, fractional anisotropy, was correlated with impaired pretreatment performance in continuous performance test omission errors and response time variability, as well as with improvement in continuous performance test response time variability after MPH treatment. Altered white matter connectivity was exclusively based on COMT genotypes, and was not evident in DAT1 or DRD4. We demonstrated that white matter connectivity in youth with ADHD is associated with COMT Val158Met genotypes. The present findings suggest that different layers of dopamine-related genes and interindividual variability in the genetic polymorphisms should be taken into account when investigating the human connectome.

No association of the norepinephrine transporter gene (SLC6A2) and cognitive and behavioural phenotypes of patients with autism spectrum disorder

We examined the association between the norepinephrine transporter (SLC6A2) gene and autism spectrum disorder (ASD) in a Korean population. In addition, we investigated which phenotypes of ASD are best attributed to the genotype of SLC6A2. A total of 184 subjects with ASD, their 156 unaffected siblings and both biological parents were recruited through university hospitals. We used the Autism Diagnostic Interview-Revised, the Aberrant Behaviour Checklist (ABC), the Child Behaviour Checklist (CBCL), the Stroop Colour-Word Interference Test and the Wisconsin Card Sorting Test (WCST) as quantitative measures of the ASD phenotypes. The associations between the quantitative measures and specific single-nucleotide polymorphisms (SNPs) were tested with linear regression analyses. We did not find any evidence of the over-transmission of either allele of the 10SLC6A2 SNPs in the DFAM test. At an empirical p value <0.05, findings that were consistent between the linear regression analyses and the QFAM tests were the positive associations between the A allele of rs36020 and attention problems on the CBCL and stereotypical behaviours on the ABC and between the C allele of rs1814270 and the number of trials required to complete the first WCST category. However, these associations did not remain after correction for multiple testing. The study results of this study do not support the association between the SLC6A2 and the diagnosis or phenotype of ASD. However, the study must be replicated in larger populations and with using more genetic markers.

Prevalence, correlates, and comorbidities of DSM-IV psychiatric disorders in children in Seoul, Korea

The present study reports past-year prevalence of and comorbidities associated with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) disorders in 1645 children aged 6 to 12 years in Seoul, Korea. The diagnosis was based on the parental version of the Diagnostic Interview Schedule for Children (DISC-IV). Our participants completed the Children's Depression Inventory (CDI). The estimated prevalence of any full-syndrome and subthreshold DSM-IV disorders were 16.2% and 28.1%, respectively. The most prevalent disorders were specific phobia (9.6%), attention-deficit hyperactivity disorder (ADHD; 5.9%), and oppositional defiant disorder (ODD; 4.9%). The estimated prevalence of depressive disorder was 0.1% according to the DISC-IV and1.9% according to the CDI. ADHD, ODD, and anxiety disorders were highly comorbid. Our study highlights the importance of obtaining children's self-report data in addition to the parents' interview, particularly for depression, and the importance of early detection of subthreshold conditions and considering comorbid diagnoses.

Subthreshold attention-deficit/hyperactivity disorder is associated with functional impairments across domains: a comprehensive analysis in a large-scale community study

This study compared children who experience attention-deficit/hyperactivity disorder (ADHD) symptoms but do not meet criteria (i.e., subthreshold ADHD) with those with the full syndrome and healthy controls. Presence of ADHD symptoms was determined in a nationwide community sample of 921 children, aged 8-11 years. The main outcome measures comprised attentional symptoms, comorbidity profiles, academic performance, and neurocognitive ability (i.e., ADHD Rating Scale, Child Behavior Checklist, Learning Disability Evaluation Scale, and Stroop Color-Word Test, respectively). Subthreshold ADHD was equally prevalent in boys and girls, and more prevalent in low-income families. Throughout all the outcome measurements, subthreshold ADHD was both a significantly milder condition than full syndrome ADHD and a significantly more severe condition than non-ADHD status. The findings were consistent across the total as well as the subtest scores, and after correction for multiple comparisons (p < 0.0017). Children with subthreshold ADHD were found to experience significant symptoms and functional impairments. The results of this study support the clinical relevance of subthreshold ADHD in a childhood population. Subthreshold diagnostic criteria for ADHD may be more sensitive in detecting ADHD symptoms in girls than the full syndrome criteria, and subthreshold clinical, cognitive, and behavioral symptoms of ADHD may occur in a subset of children who are possibly more sensitive to their environment. Further consideration about the diagnostic threshold for ADHD may particularly benefit girls and children in low-income families.

Parental quality of life and depressive mood following methylphenidate treatment of children with attention-deficit hyperactivity disorder

AIM

This naturalistic study investigated the associations between quality of life and depressive mood in parents and symptom changes in attention-deficit hyperactivity disorder (ADHD) children.

METHODS

At baseline and at weeks 4 and 8, the parents evaluated their children, who were receiving treatment with osmotic-release oral system methylphenidate (mean dosage 36.3 ± 15.5 mg/day), using the Swanson, Nolan, and Pelham - Fourth Edition (SNAP-IV-18) scale. The parents evaluated themselves using the Beck Depression Inventory (BDI) and the World Health Organization Quality of Life Assessment, Brief Version (WHOQOL-BREF).

RESULTS

A significant reduction in SNAP-IV-18 scores and improvements in parental BDI scores and parental WHOQOL-BREF scores were observed. The decrease in BDI scores from baseline to 8 weeks was significantly associated with increases in WHOQOL-BREF sub-domain scores from baseline to 8 weeks, with a greater decrease at 4 weeks and after. The decrease in the SNAP-IV-18 hyperactivity-impulsivity score was significantly associated with increases in WHOQOL social sub-domain scores from baseline to 8 weeks. For those patients who showed a 25% or greater decrease in the SNAP-IV-18 total scores from baseline to 8 weeks, the decreases in the SNAP-IV-18 total score and in the inattention and hyperactivity-impulsivity scores were significantly associated with a decrease in BDI scores from baseline to 8 weeks.

CONCLUSION

Methylphenidate treatment for ADHD was associated with both symptom alleviation in children with ADHD and improvement in parental depressive mood and quality of life, suggesting that the effects of treatment could go beyond symptom improvement in ADHD.

Catechol-O-methyltransferase Val158-Met polymorphism and a response of hyperactive-impulsive symptoms to methylphenidate: A replication study from South Korea

We investigated the association between the catechol-O-methyltransferase (COMT) Val(158)-Met (rs4680) genotype and both subjective and objective treatment responses to methylphenidate in Korean children with attention-deficit/hyperactivity disorder (ADHD). We enrolled 120 medication-naïve children with ADHD in an open-label, 8-week trial of methylphenidate. The participants were genotyped and evaluated using the Clinical Global Impression Scale and the ADHD Rating Scale-IV (ADHD-RS), and completed the Continuous Performance Test (CPT) before and after treatment. We found a significant association between the COMT Val/Val genotype and a good response, in terms of hyperactive-impulsive scores on the ADHD-RS (odds ratio (OR) = 2.61; p = 0.044) and response-time variability on the CPT (OR = 2.66; p = 0.028). The association of the COMT Val/Val genotype with a good response, in terms of response time variability, was significant in both the sub-sample of combined-type (OR = 3.45; p = 0.026) and sub-sample of inattentive-type (OR = 5.52; p = 0.029); but the association with a good response in terms of hyperactive-impulsive scores was not significant in sub-sample analyses. Although the reported nominally significant associations did not stay significant after correcting for multiple testing, our results support previous findings about the possible involvement of the COMT (Val(158)-Met) polymorphism in the treatment response to methylphenidate in children with ADHD.

Association between urine phthalate levels and poor attentional performance in children with attention-deficit hyperactivity disorder with evidence of dopamine gene-phthalate interaction

Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.

The metabotropic glutamate receptor subtype 7 rs3792452 polymorphism is associated with the response to methylphenidate in children with attention-deficit/hyperactivity disorder

OBJECTIVE

The purpose of this study was to investigate the association between the metabotropic glutamate receptor subtype 7 (mGluR7) gene (GRM7) polymorphism and treatment response to methylphenidate in Korean children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

We enrolled 175 medication-naïve children with ADHD in an open-label 8 week trial of methylphenidate. The participants were genotyped and evaluated using the Clinical Global Impressions (CGI) Scale and the parent version of the ADHD Rating Scale-IV (ADHD-RS) before and after treatment.

RESULTS

After the 8 week course of methylphenidate, children with the GRM7 rs37952452 polymorphism G/A genotype had a more pronounced response rate to the treatment than did children with the G/G genotype according to the ADHD-RS scores (72.2% vs. 55.4%, respectively; p=0.011) and the more stringent standard of combined ADHD-RS and CGI-Improvement (CGI-I) scores (50.0% vs. 35.3%, respectively; p=0.044).

CONCLUSIONS

The present study suggests that the GRM7 rs37952452 polymorphism may play a role in the treatment response to methylphenidate in children with ADHD. Further studies to evaluate the association between glutamate genes and treatment response to methylphenidate in children with ADHD, including a replication of our findings using a control or comparative group in a larger sample, are warranted.

White-matter connectivity and methylphenidate-induced changes in attentional performance according to α2A-adrenergic receptor gene polymorphisms in Korean children with attention-deficit hyperactivity disorder

The authors examined the association between the MspI C/G and DraI C/T genotypes of the α2A-adrenergic receptor gene and white-matter connectivity and attentional performance before and after medication in 53 children with attention-deficit hyperactivity disorder. Subjects who carried the T allele at the DraI polymorphism showed fewer changes in the mean commission error scores after 8 weeks of medication and decreased fractional anisotropy (FA) values in the right middle frontal cortex than subjects without the T allele. Subjects with the C allele at the MspI polymorphism showed decreased FA values in the right postcentral gyrus than subjects without.

The impact of depressive symptoms in adults with ADHD symptoms on family function and ADHD symptoms of their children

OBJECTIVE

People with attention-deficit/hyperactivity disorder (ADHD) exhibit considerable impairment in social, academic, or occupational functioning. The present study aimed to examine the patterns of associations between ADHD symptoms, depression, and family functioning.

METHODS

The sample consisted of 1,022 adults randomly selected from a district in Seoul, South Korea. Several self-assessment scales were utilized to rate ADHD symptoms (both past and current), current symptoms of depression, and level of family functioning. ADHD symptoms in the children of these participants were also assessed. Pearson's correlation and multiple linear regression analyses were performed; structural equation modeling (SEM) was conducted to determine the best fitting model.

RESULTS

Adult ADHD symptoms were positively associated with depressive symptoms. Depressive symptoms, in turn, mediated the relationship between adult ADHD symptoms and cohesion among family members. In addition, depressive symptoms mediated the relationship between adult ADHD symptoms and their children's ADHD symptoms.

CONCLUSION

The relationship between adult ADHD symptoms and family dysfunction may be influenced by depressive symptoms. When treating ADHD in adults, clinicians should pay attention to the presence or absence of depression.

Neurotrophin 3 genotype and emotional adverse effects of osmotic-release oral system methylphenidate (OROS-MPH) in children with attention-deficit/hyperactivity disorder

Neurotrophin 3 (NTF3) has been studied in relation to the pathophysiology of attention-deficit/hyperactivity disorder (ADHD) and mood disorders as well as psychostimulant action. We hypothesized that the risk of an emotional side effect to methylphenidate (MPH) treatment may be associated with NTF3 genotypes. Ninety-six medication-naïve children with ADHD (mean age 8.70, standard deviation 1.41 years, 79 males) were genotyped and treated with MPH. At baseline, which was prior to MPH treatment, and after two weeks of medication, investigators asked children and their parents or caregivers about adverse events using a symptom rating scale. ADHD subjects with the A/A genotype at the NTF3 rs6332 polymorphism showed the highest 'Emotionality' and 'Over-focus/euphoria' factor scores, followed by those with the G/A genotype and those with the G/G genotype (p=0.042 and p=0.045, respectively). ADHD subjects with the A/A genotype at the NTF3 rs6332 polymorphism showed the highest 'Proneness to crying' and 'Nail biting' item scores, followed by those with the G/A genotype and those with the G/G genotype (p=0.047 and p=0.017, respectively). These data provide preliminary evidence that genetic variation in the NTF3 gene is related to susceptibility to emotional side effects in response to MPH treatment in Korean children with ADHD.

Increased use of lethal methods and annual increase of suicide rates in Korean adolescents: comparison with adolescents in the United States

BACKGROUND

The lethality of the suicide method is a strong risk factor for completed suicide. We examined whether the annual change in the pattern of suicide methods was related to the annual change in suicide rates among adolescents in South Korea and the United States.

METHODS

We analyzed annual data for the 2000-2009 period for South Korea and the 2000-2008 period for the United States to examine time trends in the suicide rates and suicide methods of adolescents aged 10-19 years in two countries. Data on suicide methods were obtained from the World Health Organization (WHO) mortality database.

RESULTS

Suicide rates among adolescents in the United States have remained relatively steady since 2000, whereas the suicide among Korean adolescents has increased. Between 2000 and 2009, the most common suicide method among Korean adolescents was jumping for boys and girls, whereas it was hanging for girls and firearms for boys in the United States. Along with the annual increase in suicide rates in South Korea, the incidences of jumping among males and hanging (and recently jumping) among females have increased steadily, whereas suicide by self-poisoning steadily decreased. In the United States, between 2000 and 2008, the proportion of suicides committed by hanging increased, whereas those committed using firearms steadily decreased, particularly among adolescent females.

CONCLUSIONS

These findings suggest that the increased use of lethal suicide methods is reflected in the increase in suicide rates in Korean adolescents. The most fruitful approach to addressing the rises in jumping suicides among Korean adolescents and hanging suicides among adolescents in the United States may be through population-based initiatives to reduce the physical availability (e.g., limiting access to or fencing off tall structures) and the social acceptability (e.g., effective and responsible regulations for reporting suicide) of these methods.

Relationship between blood manganese levels and children's attention, cognition, behavior, and academic performance--a nationwide cross-sectional study

Manganese (Mn) is neurotoxic at high concentrations. However, Mn is an essential element that can protect against oxidative damage; thus, extremely low levels of Mn might be harmful. Our aim was to examine whether either high or low environmental Mn exposure is related to academic and attention function development among school-aged children. This cross-sectional study included 1089 children 8-11 years of age living in five representative areas in South Korea. Blood Mn, blood lead, and urine cotinine were measured. We assessed IQ with the Wechsler Abbreviated Scale of Intelligence; attention with a computerized continuous performance test called the Attention-deficit/hyperactivity disorder (ADHD) Diagnostic System (ADS), the Korean version of the Stroop Color-Word Test, the Children's Color Trails Test (CCTT), and the ADHD Rating Scale; academic functions with the Learning Disability Evaluation Scale (LDES); and emotional and behavioral problems with the Korean version of the Child Behavior Checklist (CBCL). We further assessed the presence of ADHD using a highly structured diagnostic interview, the Diagnostic Interview Schedule for Children Version IV (DISC-IV). The median blood concentration of Mn was 14.14 µg/L. We observed a nonlinear association between the CCTT2 completion time and the CPT commission error (F=3.14, p=0.03 and F=4.05, p=0.01, respectively). We divided the data into three groups: lower (<8.154 µg/L), and upper 5th percentile (>21.453 µg/L) and middle 90th percentile to determine whether a lack or overload of Mn could cause adverse effects. After adjusting for urine cotinine, blood lead, children's IQ, and other potential confounders, the high Mn group showed lower scores in thinking (B=-0.83, p=0.006), reading (B=-0.93, p=0.004), calculations (B=-0.72, p=0.005), and LQ (B=-4.06, p=0.006) in the LDES and a higher commission error in the CPT (B=8.02, p=0.048). The low Mn group showed lower color scores in the Stroop test (B=-3.24, p=0.040). We found that excess Mn in children is associated with lower scores of thinking, reading, calculation, and LQ in the LDES and higher scores of commission error in the ADS test. In contrast, lower Mn in children is associated with lower color scores in the Stroop test. The findings of this cross-sectional study suggest that excess exposure or deficiency of Mn can cause harmful effects in children.

Nocturnal enuresis is associated with attention deficit hyperactivity disorder and conduct problems

OBJECTIVE

There are no published prevalence estimates of elimination disorders and their association with disruptive-behavior disorders among children in the Asian region using standardized diagnostic interviews. This study was conducted to determine the prevalence of elimination disorders and its association with disruptive-behavior disorders in a representative sample of children in Seoul, Korea.

METHODS

The diagnosis of enuresis and encopresis was derived from parent-reported data for "enuresis and encopresis," collected using the Diagnostic Interview Schedule for Children, from a representative sample of 6- to 12-year-old children (n=1,645) who participated in the 2005 Seoul Child and Adolescent Mental Health Survey. Prevalence data for attention deficit and disruptive-behavior disorders were collected from the same sample.

RESULTS

The overall 12-month prevalence of nocturnal enuresis and encopresis was 1.8% and 0.6%, respectively. Enuresis and encopresis prevalence in boys was significantly greater than that in girls. Enuresis and encopresis was most common at 7 to 9 years of age. Enuresis was significantly associated with ADHD (OR 2.6, 95% CI 1.0-6.9) and conduct disorder (CD; OR 4.7, 95% CI 1.0-22.4).

CONCLUSION

Enuresis is significantly associated with ADHD and CD, so these conditions must be assessed together during the evaluation of children with enuresis.

Bisphenol A in relation to behavior and learning of school-age children

BACKGROUND

Bisphenol A (BPA) has been shown to affect brain and behavior in rodents and nonhuman primates, but there are few studies focusing on its relationship to human neurobehavior. We aimed to investigate the relationship between environmental exposure to BPA and childhood neurobehavior.

METHODS

Urinary BPA concentrations and behavioral and learning characteristics were assessed in a general population of 1,089 children, aged 8-11 years. The main outcome measures were the Child Behavior Checklist (CBCL) and the Learning Disability Evaluation Scale (LDES).

RESULTS

Urinary levels of BPA were positively associated with the CBCL total problems score and negatively associated with the learning quotient from the LDES. The linear association with the CBCL anxiety/depression score and the quadratic association with the LDES listening score were significant after correction for multiple comparisons.

CONCLUSIONS

Environmental exposure to BPA might be associated with childhood behavioral and learning development. The results suggest possible nonmonotonic relationships.

Baseline severity of parent-perceived inattentiveness is predictive of the difference between subjective and objective methylphenidate responses in children with attention-deficit/hyperactivity disorder

OBJECTIVE

The purpose of this study was to find potential variables associated with the difference between subjective and object treatment responses in children with attention-deficit/hyperactivity disorder (ADHD) treated with OROS-methylphenidate (MPH).

METHODS

We conducted a post-hoc analysis of data from a multicenter, open-label, 12 week trial of OROS-MPH in Korean children with ADHD. The subjective outcome measurement was the parent version of the ADHD Rating Scale-IV (ARS-P), and the objective outcome measurement was the Continuous Performance Test (CPT). We compared the children's demographic and disease-related variables among four groups, classified according to whether they showed subjective or objective improvement after MPH treatment.

RESULTS

Higher baseline inattentive scores on the ARS-P were associated with a significantly higher probability of subjective treatment response among objective nonresponders (p=0.033). Lower baseline inattentive scores on the ARS-P were associated with a significantly higher probability of subjective nonresponse among objective responders (p=0.045). Lower baseline omission errors (p=0.006) and response time variability scores (p=0.011) on the CPT were associated with a significantly higher probability of both objective and subjective responses, compared with both types of nonresponse to treatment.

CONCLUSIONS

The baseline severity of parent-perceived inattentive symptoms was predictive of differences in subjective and objective treatment responses, and the baseline severity of neuropsychological deficit (inattention and inconsistency of attention) was predictive of responses, using both subjective and objective measurements.

Impact of family environment on the development of tic disorders: epidemiologic evidence for an association

BACKGROUND

Although family education generally is recommended in the treatment of tic disorders, few studies have focused on the relationship between family environment and diagnosis of tic disorders.

METHODS

Presence of DSM-IV tic disorders was determined in a general population of 921 children in Korea from 2008 to 2009. Clinical risk factors were assessed, including comorbidity with attention-deficit/hyperactivity disorder; family-related factors such as the number of family members and primary caretaker of the child; and socioeconomic factors in the form of paternal education level and household yearly income. Multivariable logistic regression analyses were performed to estimate the association between a list of clinical, familial, and social variables and the odds of developing tic disorders.

RESULTS

At Bonferroni corrected thresholds, a higher risk of tic disorders was significantly associated with the number of changes in primary caretaker, whereas a lower risk was associated with increasing number of children in the family.

CONCLUSIONS

Family-related environmental factors may play a role in the development or exacerbation of tic disorders. The results advocate the importance of family education when treating children with tic disorders, and further research is needed on the contextual risk factors of tic disorders.

Association between the GRM7 rs3792452 polymorphism and attention deficit hyperacitiveity disorder in a Korean sample

Background

The purpose of this study was to investigate the association between the ionotropic and glutamate receptors, N-methyl D-asparate 2A (GRIN2A) and 2B (GRIN2B), and the metabotropic glutamate receptor mGluR7 (GRM7) gene polymorphisms and attention-deficit hyperactivity disorder (ADHD) in Korean population.

Methods

We conducted a case–control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test (TDT) on 149 trios, and compared scores from the continuous performance test (CPT), the Children’s Depression Inventory (CDI), and the State-Trait Anxiety Inventory for Children (STAIC) according to the genotype of the glutamate receptor genes.

Results

There were no significant differences in the genotype or allele frequencies of the GRIN2A rs8049651, GRIN2B rs2284411, or GRM7 rs37952452 polymorphisms between the ADHD and control groups. For 148 ADHD trios, the TDT analysis also showed no preferential transmission of the GRIN2A rs8049651 or GRIN2B rs2284411 polymorphisms. However, the TDT analysis of the GRM7 rs3792452 polymorphism showed biased transmission of the G allele (χ2 = 4.67, p = 0.031). In the ADHD probands, the subjects with GG genotype in the GRM7 rs37952452 polymorphism had higher mean T-scores for omission errors on the CPT than did those with the GA or AA genotype (t = 3.38, p = 0.001). In addition, the ADHD subjects who were homozygous for the G allele in the GRM7 rs37952452 polymorphism had higher STAIC-T (t = 5.52, p < 0.001) and STAIC-S (t = 2.74, p = 0.007) scores than did those with the GA or AA genotype.

Conclusions

These results provide preliminary evidence of an association between the GRM7 rs37952452 polymorphism and selective attention deficit and anxiety found within the Korean ADHD population.

Association between urine cotinine levels, continuous performance test variables, and attention deficit hyperactivity disorder and learning disability symptoms in school-aged children

BACKGROUND

We examined the cross-sectional relationship between environmental tobacco smoke exposure, continuous performance test (CPT) measures, and attention deficit hyperactivity disorder (ADHD) or learning disability symptoms in school-aged children.

METHOD

In total, 989 children (526 boys, mean age 9.1 ± 0.7 years), recruited from five South Korean cities participated in this study. We used urine cotinine as a biomarker for environmental tobacco smoke exposure, and obtained the children's scores on a CPT. Parents completed the Korean versions of the ADHD rating scale-IV (ADHD-RS) and learning disability evaluation scale (LDES). Using generalized linear mixed model (GLMM), we assessed the associations between urine cotinine concentrations, neuropsychological variables, and symptoms of ADHD and learning disabilities. Additionally, we conducted structural equation models to explore the effects' pathways.

RESULTS

After adjusting for a range of relevant covariates, GLMM showed urinary cotinine levels were significantly and positively associated with CPT scores on omission errors, commission errors, response time, and response time variability, and with parent- and teacher-rated ADHD-RS scores. In addition, urine cotinine levels were negatively associated with LDES scores on spelling and mathematical calculations. The structural equation model revealed that CPT variables mediated the association between urine cotinine levels and parental reports of symptoms of ADHD and learning disabilities.

CONCLUSIONS

Our data indicate that environmental exposure to tobacco smoke is associated with ADHD and learning disabilities in children, and that impairments in attention and inhibitory control probably mediate the effect.

Dopaminergic and noradrenergic gene polymorphisms and response to methylphenidate in korean children with attention-deficit/hyperactivity disorder: is there an interaction?

OBJECTIVE

We aimed to investigate the independent and interaction effects of dopamine transporter gene (DAT1), dopamine D4 receptor gene (DRD4), alpha-2A adrenergic receptor gene (ADRA2A), and norepinephrine transporter gene (NET1), with regard to treatment response to methylphenidate (MPH) in attention-deficit/hyperactivity disorder (ADHD).

METHODS

The participants of the study were 103 children and adolescents (ages 9.1±2.1 years) diagnosed as having ADHD according to American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria. They were enrolled in an 8-week, open-label trial of MPH. The good responder group was defined as subjects having an ≥50% decrease in the ADHD Rating Scale-IV (ADHD-RS) total score from the baseline, and at the same time a Clinical Global Impressions-Improvement Scale (CGI-I) score of 1 or 2, both at the 8th week of MPH treatment. Multivariate stepwise logistic regression was performed to examine the independent and interaction effects of genotypes on the dichotomized MPH treatment response.

RESULTS

Significant interaction effects on MPH response were detected between the genotypes of the DRD4 variable number of tandem repeat (VNTR) polymorphisms and those of either the ADRA2A DraI or the NET1 -3081(A/T) polymorphisms; significant interaction effects were also detected between the genotypes of the ADRA2A DraI polymorphisms and those of either the NET1 G1287A or the NET1 -3081(A/T) polymorphisms (Nagelkerke R(2)=0.40). No significant independent effect of a genotype was detected according to the stepwise logistic regression results.

CONCLUSION

The results suggest that genes involved in the dopaminergic and noradrenergic systems might interact to form important predictors of short-term response to MPH.

Serotonin 2A Receptor Gene Polymorphism in Korean Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

The purpose of this study was to investigate the association between the T102C polymorphism in the serotonin 2A receptor gene and attention-deficit/hyperactivity disorder (ADHD) in Korean patients.

METHODS

A total of 189 Korean children with ADHD as well as both parents of the ADHD children and 150 normal children participated in this study. DNA was extracted from blood samples from all of the subjects, and genotyping was conducted. Based on the allele and genotype information obtained, case-control analyses were performed to compare the ADHD and normal children, and Transmission disequilibrium tests (TDTs) were used for family-based association testing (number of trios=113). Finally, according to the significant finding which was showed in the case-control analyses, the results of behavioral characterastics and neuropsychological test were compared between ADHD children with and without the C allele.

RESULTS

In the case-control analyses, statistically significant differences were detected in the frequencies of genotypes containing the C allele (χ(2)=4.73, p=0.030). In the family-based association study, TDTs failed to detect linkage disequilibrium of the T102C polymorphism associated with ADHD children. In the ADHD children, both the mean reaction time and the standard deviation of the reaction time in the auditory continuous performance test were longer in the group with the C allele compared to the group without the C allele.

CONCLUSION

The results of this study suggest that there is a significant genetic association between the T102C polymorphism in the serotonin 2A receptor gene and ADHD in Korean children.

Association between dietary behaviors and attention-deficit/hyperactivity disorder and learning disabilities in school-aged children

We aimed to comprehensively investigate the associations between a wide range of measures of dietary behaviors and learning disabilities and attention-deficit/hyperactivity disorder (ADHD) in community-dwelling Korean children in order to generate hypotheses for future work. The present study included 986 children [507 boys, 479 girls; mean (S.D.) age=9.1 (0.7) years] recruited from five South Korean cities. Children's dietary behaviors were assessed by the mini-dietary assessment (MDA) for Koreans. It consists of ten items to assess the level of intake of dairy products, high-protein foods, vegetables, fried foods, fatty meats, salt, and sweetened desserts and whether the subject is eating three regular meals and has a balanced diet. Learning disability was assessed via the Learning Disability Evaluation Scale (LDES). ADHD was assessed via the Diagnostic Interview Schedule for Children version-IV and the ADHD rating scale, and ADHD-related behavioral problems were assessed via the Child Behavior Checklist. After adjusting for potential confounders, a high intake of sweetened desserts, fried food, and salt is associated with more learning, attention, and behavioral problems, whereas a balanced diet, regular meals, and a high intake of dairy products and vegetables is associated with less learning, attention, and behavioral problems. Our data suggest that existing encouraged dietary habits mostly have beneficial effects on learning, attention, and behavioral problems in Korean children. These findings are in general the same results in other studies on ADHD children in other countries. However, the cross-sectional study design prevents our ability to assess causal relationships.