Objectives: This study investigated the relationship between exposure to endocrine-disrupting chemicals (EDCs), specifically phthalates, bisphenol A, bisphenol F, and bisphenol S, and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms using neuropsychological tests in children diagnosed with ADHD. Methods: This study included 67 medication-naïve children with ADHD aged 6–16 years. The urinary concentrations of EDCs were measured, and ADHD symptom severity was evaluated using neuropsychological tests and clinical symptom scale measurements. The Jonckheere–Terpstra test, Pearson and Spearman correlation analyses, linear regression models, and multiple regression models were used to examine the relationship between EDC exposure and ADHD symptoms. Results: A significant correlation was observed between urinary phthalate metabolite concentrations and commission error T-scores in the visual Advanced Test of Attention test. No significant associations were found with other neuropsychological indicators or bisphenol levels. Conclusion Phthalate exposure affects impulsivity in children with ADHD, which is consistent with the results of previous studies that used parental surveys. However, bisphenols are not clearly associated with ADHD symptoms, which is consistent with the results of previous studies.

Objectives: This study investigated the relationship between exposure to endocrine-disrupting chemicals (EDCs), specifically phthalates, bisphenol A, bisphenol F, and bisphenol S, and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms using neuropsychological tests in children diagnosed with ADHD. Methods: This study included 67 medication-naïve children with ADHD aged 6–16 years. The urinary concentrations of EDCs were measured, and ADHD symptom severity was evaluated using neuropsychological tests and clinical symptom scale measurements. The Jonckheere–Terpstra test, Pearson and Spearman correlation analyses, linear regression models, and multiple regression models were used to examine the relationship between EDC exposure and ADHD symptoms. Results: A significant correlation was observed between urinary phthalate metabolite concentrations and commission error T-scores in the visual Advanced Test of Attention test. No significant associations were found with other neuropsychological indicators or bisphenol levels. Conclusion Phthalate exposure affects impulsivity in children with ADHD, which is consistent with the results of previous studies that used parental surveys. However, bisphenols are not clearly associated with ADHD symptoms, which is consistent with the results of previous studies.

Objectives: This study investigated the relationship between exposure to endocrine-disrupting chemicals (EDCs), specifically phthalates, bisphenol A, bisphenol F, and bisphenol S, and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms using neuropsychological tests in children diagnosed with ADHD. Methods: This study included 67 medication-naïve children with ADHD aged 6–16 years. The urinary concentrations of EDCs were measured, and ADHD symptom severity was evaluated using neuropsychological tests and clinical symptom scale measurements. The Jonckheere–Terpstra test, Pearson and Spearman correlation analyses, linear regression models, and multiple regression models were used to examine the relationship between EDC exposure and ADHD symptoms. Results: A significant correlation was observed between urinary phthalate metabolite concentrations and commission error T-scores in the visual Advanced Test of Attention test. No significant associations were found with other neuropsychological indicators or bisphenol levels. Conclusion Phthalate exposure affects impulsivity in children with ADHD, which is consistent with the results of previous studies that used parental surveys. However, bisphenols are not clearly associated with ADHD symptoms, which is consistent with the results of previous studies.

Autism spectrum disorder (ASD) is diagnosed by the clinical decision of a trained professional based on the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition or International Classification of Diseases 11th Revision diagnostic criteria. To obtain information for diagnostic formulation, professionals should explore detailed developmental history, and can use structured or semi-structured assessment tools to observe interaction between the child and parents or strangers. Diagnostic assessment should include a profile of the strength and weaknesses of the individual and should be conducted using an optimal approach by a multidisciplinary team with appropriate techniques and experience. Assessment of language, cognitive, neuropsychological, and adaptive functioning should be conducted in ASD individuals prior to establishing an individualized treatment plan. Genetic testing, brain magnetic resonance imaging or electroencephalogram testing can be considered for identification of underlying causes.

Objective: This study aimed to investigate the prevalence, clinical characteristics, and the correlates of nonsuicidal self-injury (NSSI) in firefighters. We also investigated the mediating role of NSSI frequency in the association between posttraumatic stress disorder (PTSD), depression, and suicidal behavior. Methods: A total of 51,505 Korean firefighters completed a web-based self-reported survey, including demographic and occupational characteristics, NSSI, PTSD, depression, and suicidal behavior. Multivariable logistic regression analyses and serial mediation analyses were performed. Results: The 1-year prevalence of NSSI was 4.67% in Korean firefighters. Female gender, the presence of recent traumatic experience, and PTSD and depression symptoms were correlated with NSSI. Serial mediation analyses revealed that NSSI frequency mediated the association between PTSD, depression, and suicidal behavior; it indicates more severe PTSD was sequentially associated with more severe depression symptoms and more frequent NSSI, leading to higher risk of suicidal behavior. Conclusion NSSI is prevalent and may play a significant mediating role when PTSD is associated with suicidal behavior in firefighters. Our results imply the need for screening and early intervention of NSSI in firefighters.

Objective: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children and adults characterized by cognitive and emotional self-control deficiencies. Previous functional near-infrared spectroscopy (fNIRS) studies found significant group differences between ADHD children and healthy controls during cognitive flexibility tasks in several brain regions. This study aims to apply a machine learning approach to identify medication-naive ADHD patients and healthy control (HC) groups using task-based fNIRS data. Methods: fNIRS signals from 33 ADHD children and 39 HC during the Stroop task were analyzed. In addition, regularized linear discriminant analysis (RLDA) was used to identify ADHD individuals from healthy controls, and classification performance was evaluated. Results: We found that participants can be correctly classified in RLDA leave-one-out cross validation, with a sensitivity of 0.67, specificity of 0.93, and accuracy of 0.82. Conclusion RLDA using only fNIRS data can effectively discriminate children with ADHD from HC. This study suggests the potential utility of the fNIRS signal as a diagnostic biomarker for ADHD children.

Objective: Underconnectivity in the resting brain is not consistent in autism spectrum disorder (ASD). However, it is known that the functional connectivity of the default mode network is mainly decreased in childhood ASD. This study investigated the brain network topology as the changes in the connection strength and network efficiency in childhood ASD, including the early developmental stages. Methods: In this study, 31 ASD children aged 2–11 years were compared with 31 age and sex-matched children showing typical development. We explored the functional connectivity based on graph filtration by assessing the single linkage distance and global and nodal efficiencies using resting-state functional magnetic resonance imaging. The relationship between functional connectivity and clinical scores was also analyzed. Results: Underconnectivities within the posterior default mode network subregions and between the inferior parietal lobule and inferior frontal/superior temporal regions were observed in the ASD group. These areas significantly correlated with the clinical phenotypes. The global, local, and nodal network efficiencies were lower in children with ASD than in those with typical development. In the preschool-age children (2–6 years) with ASD, the anterior-posterior connectivity of the default mode network and cerebellar connectivity were reduced. Conclusion The observed topological reorganization, underconnectivity, and disrupted efficiency in the default mode network subregions and social function-related regions could be significant biomarkers of childhood ASD.

Background: School-aged children born very preterm have been suggested to have worse cognitive and behavioral outcomes than children born full-term. Executive function (EF) is a higher level of cognitive function related to academic achievement. The present study aimed to evaluate the cognitive (including EF) and behavioral outcomes of Korean children born extremely preterm (EP) and to analyze any biological or socioeconomic risk factors for poor cognitive outcomes in this population. Methods: A total of 71 infants weighing < 1,000 g at birth or born before 30 weeks of gestation (EP group) who were admitted to the neonatal intensive care unit from 2008 to 2009 were included in this study and compared with 40 term-birth controls. The Korean Wechsler Intelligence Scale for Children-Fourth Edition, Advanced Test of Attention (ATA), Stroop test, Children's Color Trails Test (CCTT), and Wisconsin Card Sorting Test (WCST) were used.Additionally, the Korean Child Behavior Checklist (K-CBCL) and Korean ADHD Rating Scale (K-ARS) were completed. Perinatal and demographic data were collected and analyzed. Results: The mean full-scale intelligence quotient (FSIQ) score in the EP group was significantly lower than that of the term control group (89.1 ± 18.3 vs. 107.1 ± 12.7; P < 0.001).In the EP group, 26 (37%) children had an FSIQ score below 85, compared to only one child (3%) in the control group. Furthermore, the EP group showed significantly worse EF test results (ATA, Stroop test, CCTT, WCST). Except for the higher social immaturity subscore in the EP group, the K-CBCL and K-ARS scores were not different between the two groups. EP children who received laser treatment for retinopathy of prematurity (ROP) had an 8.8-fold increased risk of a low FSIQ score, and a 1-point increase in the discharge weight Z-score decreased the risk of a low FSIQ score by approximately half in this EP cohort. Conclusion This is the first Korean study to investigate the cognitive and behavioral outcomes of school-aged children born EP. In the study cohort, EP children exhibited significantly lower FSIQ scores and EF than their full-term peers, and 37% of them had cognitive problems. Nonetheless, except for social immaturity, the behavioral problems werenot different in EP children. Severe ROP and low discharge weight Z-score were identified as independent risk factors for low FSIQ score after adjusting for birth weight.

Objectives: Bisphenol A (BPA) is used in the electrical, mechanical, medical, and food industries. Previous studies have suggested that BPA is an endocrine disruptor. Regulation of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). However, few studies have investigated the associations of BPF and BPS with thyroid dysfunction in children. Our study investigated the associations of prenatal BPA and early childhood BPA, BPF, and BPS exposure with thyroid function in 6-year-old children. Methods: Prenatal BPA concentrations were measured during the second trimester of pregnancy in an established prospective birth cohort. We measured urinary BPA, BPF, and BPS concentrations and thyroid hormone levels (thyroid-stimulating hormone, total T3, and free T4) in 6-year-old children (n=574). We examined the associations between urinary bisphenol concentrations and percentage change of thyroid hormone concentrations using multivariate linear regression. We also compared thyroid hormone levels by dividing the cohort according to BPA, BPF, and BPS concentrations. Results: The associations between prenatal BPA and total T3 levels were statistically significant in all models, except for girls when using a crude model. The associations between urinary BPA and BPS concentrations and levels of all thyroid hormones were not statistically significant. However, we observed that lower free T4 levels (-1.94%; 95% confidence interval, -3.82 to -0.03) were associated with higher urinary BPF concentrations in girls only. Conclusions Our findings identified significant associations between prenatal BPA exposure and total T3 levels in all children and between BPF exposure and free T4 levels in girls only.

Objective: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. In contrast to neurocognitive measurements of inattention and impulsivity, there has been limited research regarding the objective measurement of hyperactivity in youths with ADHD. The purpose of the present study was to investigate the clinical effectiveness of a newly developed Robot-assisted Kinematic Measure for ADHD (RAKMA) in children with ADHD. Methods: In total, 35 children with ADHD aged 5 to 12 years and 50 healthy controls (HCs) were recruited, and the parents completed the Child Behavior Checklist and the Korean ADHD Diagnostic Scale. RAKMA performance was represented by RAKMA stimulus–response and hyperactivity variables. We compared the RAKMA performance of those with ADHD and with that of HCs and also investigated the correlation between the RAKMA variables and ADHD clinical scale scores. Results: Significant differences between the ADHD and HC groups were observed regarding most RAKMA variables, including correct reactions, commission errors, omission errors, reaction times, migration distance, and migration speed scores. Significant correlations were detected between various ADHD clinical scale scores and RAKMA variables. Conclusion The RAKMA was a clinically useful tool for objectively measuring hyperactivity symptoms in children with ADHD. Further studies with larger samples are warranted.