Myung-Ho Lim

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.

Children's mental health in the area affected by the Hebei Spirit oil spill accident

Objectives Children are one of the most vulnerable populations to the impact of disasters. We aimed to examine childrens mental health in the area affected by the Hebei Spirit oil spill accident on December 7, 2007. Methods A cross-sectional questionnaire survey was conducted using the Korean versions of the Childrens Depression Inventory and State Anxiety Inventory for Children on 1,362 children attending elementary schools in the affected area. The information on distances between the nearest contaminated coastline to the childs residential house or attending school were obtained using a web-based map by inputting two address points. The symptom risks of depression and state anxiety were estimated by multiple logistic regression analyses adjusted for age, gender, and other covariates. Results Children with the closest distance (in the fourth quartile) to the school from the contaminated coastline showed a significantly higher symptom risk of depression compared to those with the farthest distance (first quartile)(odds ratio, 2.73; 95% confidence interval, 1.40-5.33), while there was no significant association between anxiety symptoms and distance. Conclusions Children, a vulnerable population for mental health impact by the oil spill accident, should be included in mental health programs in the community along with their family as victims of the disaster.

Relationship among attention-deficit hyperactivity disorder, dietary behaviours and obesity

BACKGROUND Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood and can be associated with obesity. The aim of this study was to reveal the connection between ADHD symptoms, food habits and obesity. METHODS We examined 12 350 children (6010 boys, 6340 girls) from 27 elementary schools in Cheonan, the Republic of Korea. The study subjects were 5- to 13-year-old children (9.4 ± 1.7 years). Parents completed the DuPaul ADHD Rating Scale. Food habits were measured by a questionnaire adapted from the Korea Youth Risk Behavior Web-based Survey and a validated mini-dietary assessment tool. The full set of hypothesized associations was tested using covariance structural modelling. RESULTS The prevalence of ADHD was 7.6% and that of obesity was 4.5% in our study population. The data was well fit by the model. ADHD was associated with body mass index (BMI; standardized β = 0.086, P < 0.001). Bulimic dietary behaviours was related to BMI (standardized β = 0.548, P < 0.001). Socio-economic status was associated with BMI (standardized β = -0.017, P = 0.027). CONCLUSION Our analysis suggested that ADHD was a risk factor for obesity through dietary behavioural change and socio-economic status.

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.

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.

Methylphenidate-osmotic-controlled release oral delivery system treatment reduces parenting stress in parents of children and adolescents with attention-deficit/hyperactivity disorder.

The aim of the current study was to investigate the effect of methylphenidate‐osmotic release oral delivery system (MPH‐OROS) treatment on parenting stress in parents of children and adolescents with attention‐deficit/hyperactivity disorder (ADHD).

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.

Association of glutathione S-transferases M1, T1 and P1 gene polymorphisms with attention deficit and hyperactivity disorder in Korean children

Attention deficit and hyperactivity disorder (ADHD) is highly heritable disorder and common in school-age children characterized by inattention, hyperactivity and impulsivity. Although its heritability was estimated at 80-90% from family, adoption and twin studies, the molecular etiology of this disorder has not elucidated. Meanwhile, an impaired balance of oxidant-antioxidant status and increased oxidative stress is observed in ADHD, and it may imply a possible relationship between oxidative stress and etiology of ADHD. Glutathione S-transferase (GST) is antioxidant enzymes that play a key role in the cellular detoxification. In the present study, we examined the association between the genetic polymorphisms of GSTM1, GSTP1 and GSTT1, and ADHD in Korean children. Case-control study was conducted with 243 ADHD children and 327 controls. There were no significant associations between the polymorphisms and the incidence of ADHD (p>0.05). However, significant associations were observed in the stratified analyses. The frequency of GSTP1 Ile/Ile genotype is reached to the significant level in the hyperactivity subtype (88.2%) compared to controls (64.8%) (p=0.035) and the frequency of GSTT1-null genotype is significantly higher in the inattentive boys (p=0.005). Similarly, GSTT1-null genotype showed significant associations in combined subtype (p=0.016) and hyperactivity subtype (p=0.036) of the ADHD girls. Thus our result imply that the polymorphisms in the GST genes may affect ADHD, however, replication study for larger sample set and functional studies are crucial to confirm these findings.