Relations of Vocabulary and Cognitive Skills With Reading Performance of North Korean Students in South Korean Schools.

We examined if North (n = 123) and South Korean (n = 123) children in Grades 3 to 8 studying in South Korea differ in their reading, vocabulary, and literacy-related cognitive skills, and whether language and literacy-related skills contribute to reading outcomes differently among North and South Korean children. The results showed that South Korean students performed better in syllable deletion, RAN-Letters, vocabulary, decoding fluency, and reading comprehension after controlling for age and SES. No differences were observed in phonological awareness, RAN-Digits, and visual processing tasks. A multigroup path analysis showed that phonological awareness and vocabulary were more strongly associated with decoding fluency for the South than the North Korean students, whereas the opposite was true for visual processing. The results suggest that South Korean vocabulary knowledge may be a significant factor in addressing the academic difficulties facing North Korean children in South Korean schools and that it is important to consider linguistic characteristics when examining the variations in reading skills and vocabulary knowledge of North Korean students in South Korean schools. These findings have implications for North Korean children's literacy instruction in South Korean schools.

Factors Associated With Media Addiction in Korean Elementary School Children.

The aim of this study was to identify the prevalence of media addiction and its associated factors in elementary school children based on the problem behavior theory. This cross-sectional study was a secondary data analysis using national data from the 10th Panel Study on Korean Children 2017, which included 1,078 families of third-grade students (8-9 years of age). Descriptive statistics were used to examine the prevalence of media addiction, and logistic regression analysis was conducted to identify factors associated with media addiction. Prevalence of media addiction was 22.91% in this sample. Media addiction was significantly associated with general characteristics (gender, education level of mother, and time spent without parents), socialization (media use time), factors in the personal system (happiness), and factors in the perceived-environment system (parenting style). More comprehensive, tailored education may prevent elementary school children's media addiction. In addition, parents should participate in media addiction education with their children.

Influenza Vaccine Effectiveness among Elementary School Students in Korea during the 2016-2017 Seasons: a Cross-Sectional Survey.

BACKGROUND: Annual vaccination is the principal way to reduce the mortality and morbidity associated with influenza. In the 2016-2017 influenza seasons, the influenza epidemic appeared to exhibit a different pattern from the previous years. Because of the unusual trend, the incidence of influenza-like patients among school-aged children had increased, causing doubts about the effectiveness of the influenza vaccine. Therefore, this study aimed to evaluate the effectiveness of the influenza vaccine among elementary school students in Korea. METHODS: The study was conducted in elementary schools in each province of Korea in cooperation with the Student Health Policy Division of the Ministry of Education. Each Provincial Office of Education of Korea, except for Jeju, randomly selected one to two elementary schools for each District Office of Education. A total of 2,739 elementary school students were enrolled and vaccination and influenza infection status were collected from the subjects' parents through questionnaires, from February 13th to 21st in 2017. Vaccine effectiveness was defined as calculating the infection rate of influenza among the vaccinated and unvaccinated groups and determining the decreased infection rate of the vaccinated group relative to the unvaccinated group, while adjusting for time of vaccination and infection. RESULTS: Adjusting for the interval between vaccination and infection, vaccine effectiveness of influenza was 17.6% (95% confidence interval [CI], 4.6% to 28.9%), 22.5% (95% CI, 10.3% to 33%), and 28.7% (95% CI, 17.5% to 38.3%) at 2 or more weeks, 3 or more weeks, and 4 or more weeks after vaccination, respectively. CONCLUSION: In conclusion, considering the time required for adequate immunogenicity, the 2016-2017 seasonal influenza vaccine effectiveness in Korean elementary school students was 17.6%-28.7%, which was less effective than that of previous years.

Positive Changes in Blood Lipid Profiles, Nutrition Knowledge, and Dietary Taurine Intake After 8-Week Nutrition Education Program in Low-Income Korean Children.

Taurine has been reported to play a key role in the growth and development of children's brains and nerves. Incorrect dietary habits and unbalanced nutrient intakes may be caused by socio-environmental and economic factors in low-income children. This study was conducted to investigate changes in blood lipid profiles, nutrition knowledge, dietary attitudes, and intakes of dietary taurine and nutrients after an 8-week nutrition education program (NEP) in low-income Korean children. In this intervention study, nutrition education, exercise, and nutrition counseling were conducted for 8-weeks in 22 low-income children (11-13 years old, 9 males and 13 females) at community child center located in Incheon, Korea. Changes after the NEP were evaluated using a one group pretest-posttest design. Statistical analysis was performed using SPSS 20.0. After the 8-week NEP, there was a significant decrease in the blood triglyceride level of female students (p < 0.01). As for nutrition knowledge, there were significant increases in the subscore of sugars and sodium in foods consumed by male students (p < 0.05), total score of nutrition knowledge (p < 0.01), subscore of sugars and sodium in foods (p < 0.01), and fat content of foods and adequate dietary intake in female students (p < 0.05). Dietary attitudes did not change. There were significant increases in intakes of dietary taurine, vitamin B6 (p < 0.01), and dietary fiber (p < 0.05) in female students after the NEP. There were significantly positive correlations between changes in dietary taurine intake and dietary attitudes as well as between changes in carbohydrate intake and total cholesterol level among all the subjects. Therefore, nutrition education to promote balanced nutrient intake and dietary attitudes for optimal growth and development of low-income children is needed.

Correlation between Dental Maturity and Body Mass Index in Korean Children.

Objective: The aim of this study was to determine relationships between dental maturity and body mass index (BMI) in Korean children. Study Design: 600 Korean children aged between 5 and 10 years for whom panoramic radiographs have been obtained between 2010 and 2017 were selected. Subjects were divided into four weight-status groups: underweight, normal weight, overweight, and obese. Five lower-left permanent teeth were observed and rated. The stage of each tooth was converted into a score using the table suggested by Demirjian, and the sum of these scores was designated as the 'maturity score'. Results: This study found statistically significant differences in dental maturity between the weight groups (analysis of variance, P=0.003), with the maturity score being higher in the obese group than in normal-weight subjects (Tukey's post-hoc test, P=0.004). The linear regression showed a positive association between BMI and the maturity score after adjusting for sex and age (ß=0.34, P<0.001). The linear regression coefficient was higher in girls (ß=0.61, P<0.001) than in boys (ß=0.31, P=0.02). Conclusions: These data suggest that dental maturation is positively associated with BMI in Korean children. Since many treatment decisions are made in relation to dental maturity, these findings may have implications for pediatric dental care.

Multidimensional factors of determining trajectories in self-rated health and depressive symptoms among Korean children and adolescents.

Understanding health disparities in the early stage of life is complicated by the complex interplay of psychosocial and environment factors. Despite these complexities, few studies have investigated multidimensional aspects of determining health trajectories of Korean children and adolescents. Thus, this study aims to investigate the impact of intrapersonal, interpersonal, and environmental factors on trajectories in self-rated health and depressive symptoms. Totally, 2378 Korean student samples were selected from the Korean Children and Young Panel Survey for data analysis. The findings indicated that higher levels of self-esteem, attachment to parents, and relationship with friends predicted better self-rated health and less depressive symptoms at baseline. Perception on community only predicted better self-rated health but not depressive symptoms at baseline. Among multidimensional factors, only self-esteem predicted the rate of changes in self-rated health and depressive symptoms. This study suggested that enhancing self-esteem and supportive environment should be provided throughout childhood and adolescence.

Association of Monoamine Oxidase A (MAOA) Gene uVNTR and rs6323 Polymorphisms with Attention Deficit and Hyperactivity Disorder in Korean Children.

Objective: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. The genetic cause of ADHD is still unclear, but the dopaminergic, serotonergic, and noradrenergic pathways have shown a strong association. In particular, monoamine oxidase A (MAOA) plays an important role in the catabolism of these neurotransmitters, suggesting that the MAOA gene is associated with ADHD. Therefore, we evaluated the relationship between the MAOA gene polymorphisms (uVNTR and rs6323) and ADHD. Materials and methods: We collected a total of 472 Korean children (150 ADHD cases and 322 controls) using the Korean version of the Dupaul Attention Deficit Hyperactivity Disorder Rating Scales (K-ARS). Genotyping was performed by PCR and PCR-RFLP. The Behavior Assessment System for Children Second Edition (BASC-2) was used to evaluate the problem behaviors within ADHD children. Results: We observed significant associations between the rs6323 and ADHD in girls (p < 0.05) and the TT genotype was observed as a protective factor against ADHD in the recessive model (OR 0.31, 95% CI 0.100⁻0.950, p = 0.022). The 3.5R-G haplotype showed a significant association in ADHD boys (p = 0.043). The analysis of subtype also revealed that the 4.5R allele of uVNTR was a risk factor for the development of ADHD in the combined symptom among girls (OR 1.87, 95% CI 1.014⁻3.453, p = 0.031). In the BASC-2 analysis, the MAOA uVNTR polymorphism was associated with activities of daily living in ADHD boys (p = 0.017). Conclusion: These results suggest the importance of the MAOA gene polymorphisms in the development of ADHD in Korean children. A larger sample set and functional studies are required to further elucidate of our findings.

A multicenter study on anaphylaxis caused by peanut, tree nuts, and seeds in children and adolescents.

Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009-2013). One hundred and twenty-six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kUA /l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.

Nasalance Variability in 3- to 5-Year-Old Children during Production of Speech Stimulus in Three Vowel Contexts.

OBJECTIVE: The purpose of this study was to determine whether age and vowel contexts influence test-retest nasalance score variability in typically developing Korean children. PARTICIPANTS: Forty-five 3- to 5-year-old children with normal speech and resonance participated in the study. METHODS: All subjects were asked to repeat three 4-syllable speech stimuli in high, low, or mixed vowel contexts twice after the examiner. An immediate test-retest nasalance score was assessed with no headgear change. Test and retest variability in nasalance scores was examined based on the absolute difference in nasalance scores of the first and second repetition for each stimulus. RESULTS: A significant main effect of the vowel context on variability in nasalance scores was found, but the effect of age on nasalance variability was not significant. Mean absolute difference in nasalance scores for the stimuli in the high vowel contexts was significantly greater than for the stimuli in the low and mixed vowel contexts. CONCLUSIONS: The results suggested that variability in nasalance scores might not decrease with age and tend to show considerable individual variations. Increased variability in nasalance scores in the high vowel context might be associated with aerodynamic and acoustic characteristics resulting from physiological aspects of the vowel /i/.

Nutrition in Chinese-Korean Children and Adolescents.

OBJECTIVE: To study the nutrition habits among Chinese-Korean children and adolescents in Yanbian Autonomous Prefecture, Jilin, China. METHODS: Data were obtained from the Chinese National Survey on Students' Constitution and Health in 1995, 2000, 2005, and 2010 for Chinese-Korean children and adolescents aged 7-18 years. The number of the subjects included was 4789, 4704, 5875, and 5315, respectively. RESULTS: The rate of the occurrence of stunting showed a declining trend from 1995 to 2010 (for boys: urban, 6.3%; rural, 12.7% in 1995 and 3.5% for both in 2010. For girls: urban, 7.8%; rural, 13.4% in 1995 and 4.2% and 5.5%, respectively, in 2010). Although the ratio of wasting did not show significant differences between the urban and rural children and adolescents in 1995, 2000, 2005, and 2010 respectively, the ratio of occurrence of overweight or obesity increased (for boys: urban, 7.3% and 1.3% in 1995, 17.6% and 12.9% in 2010; rural, 7.0% and 1.3% in 1995, 14.6% and 12.8% in 2010, respectively. For girls: urban, 8.1% and 1.0% in 1995, 17.3% and 8.6% in 2010; rural 5.7% and 0.7% in 1995, 16.4% and 7.4% in 2010, respectively). CONCLUSION: The ratio of malnutrition in children and adolescents in Chinese-Korean areas declined from 1995 to 2010, and the distinction in malnutrition between the urban and rural areas was negligible in 2010. Further, the ratio of overweight and obesity increased over this period.

Validity of the BOT-2 Short Form for Korean School-Age Children: A Preliminary Study.

The Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2) is the most common motor assessment in Korea. The BOT-2-Short Form (SF) is preferred over the complete form (CF) in settings with limited time. The present study aimed to assess the validity of the BOT-2 SF in Korean school-age children. First, we verified that the BOT-2 SF reflects developmental changes in motor skills. Second, we compared the BOT-2 SF scores to those of the BOT-2 CF. A total of 283 Korean school-age children performed the BOT-2. The differences in the BOT-2 SF point according to age group (7 years, 8-9 years, and 10-12 years) were analyzed. A correlation analysis of the standard scores between the BOT-2 SF and CF was conducted. The sensitivity and specificity of the BOT-2 SF were calculated in reference to its CF. Overall, the BOT-2 SF point scores increased with age. The correlation between the total scores of the BOT-2 SF and CF was strong. The BOT-2 SF had a sensitivity of 83% and specificity of 92%. This study has demonstrated the validity of the BOT-2 SF in Korean school-age children. The BOT2 SF can be useful in screening Korean school-age children with motor skills problems.

Lack of association between the Y chromosome haplogroups and attention deficit hyperactivity disorder (ADHD) in Korean boys.

Attention deficit hyperactivity disorder (ADHD) is a major neurodevelopmental disorder including multiple environmental and biological causes. It is generally reported that the prevalence of ADHD is 4-fold higher in boys than in girls. Previous studies have reported that the Y-linked genes have been significantly associated with neuropsychiatric disorders. Furthermore, several Y chromosome haplogroups have been reported to be related to the development of ADHD symptoms. Therefore, we analyzed the genetic correlation between the Y chromosome haplogroups and ADHD in the Korean boys. Our results showed that the Y chromosome haplogroup O2b (xO2b1) (p = 0.053) and O3a3c1 (p = 0.050) has a trend of borderline statistical significance. In subtype analysis, a significant association was observed between haplogroup O3a3c1 and the ADHD/C [odds ratio (OR), 3.43; 95 % confidence interval (CI), 1.336 - 8.782; p = 0.007]. However, this association could not pass the Bonferroni correction for multiple testing. In conclusion, our results showed a lack of association between Y chromosome haplogroups and the occurrence of ADHD in Korean boys.

Association between genetic polymorphisms of synaptophysin (SYP) gene and attention deficit hyperactivity disorder in Korean subjects.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a common childhood neurodevelopmental disorder, and the prevalence of ADHD among Korean children has attained about 8.5%. Various genetic factors can contribute to the etiology of the disease. Synaptophysin (SYP) regulates neurotransmitter release and synaptic plasticity. According to previous studies, several genetic polymorphisms on SYP were risk factors for ADHD. OBJECTIVE: We investigated the effect of the SYP gene polymorphisms (rs2293945 and rs3817678) on ADHD in Korean children. METHODS: In this study, we examined the case-control study in 150 ADHD cases and 322 controls. The genotyping of SYP gene polymorphisms was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Significant associations in the genotype and genetic models of SYP rs2293945 polymorphism between girls with ADHD and control girls were found. The girls with ADHD having the C/T genotype were significantly associated with ADHD. In the dominant model of rs3817678, C/T + T/T genotypes were significantly associated with ADHD. The haplotype analyses showed significant associations from haplotypes of rs2293945 T-rs3817678 G and rs2293945 C-rs3817678 A. CONCLUSION: Our results imply that the SYP rs2293945 C/T polymorphism in female participants may provide a possible effect on the genetic etiology of ADHD.

Effects of an Orff Music Activity Intervention Program on the Ego-Resilience, Peer Relationships, Happiness, Interpersonal Care Awareness, Anxiety, and Stress of Children from Multicultural Families in Republic of Korea.

This study developed an interpersonal care-based Orff music activity program for children from multicultural families in Republic of Korea. We measured its effects on ego-resilience, peer relationships, happiness, interpersonal care awareness, anxiety, and stress. The participants were 74 children from third to sixth grade attending 10 regional children's centers in Cheonan-si, Chungcheongnam-do Province, Republic of Korea. They were randomly assigned to 36 experimental groups and 38 control groups. The experimental program was developed based on investigations of human care theory, expressions of care, and Orff music activities. The experiment was conducted twice a week for five weeks in 45 min sessions. Data were collected from June to September 2020. We used questionnaires on ego-resilience, peer relationships, happiness, and interpersonal care awareness to measure the effects, which were analyzed through frequency and descriptive statistics. Anxiety, physiological anxiety, acculturation stress, and physiological stress were measured using Behavior Detection VibraImage System Version 8.1 PRO (VIBRASYSTEM Ltd., Co., Seoul, Republic of Korea). The homogeneity of the variables across groups was examined using the χ² test, t-test, and Fisher's exact test. The effects were examined using repeated measures variance analysis and independent t-tests. The results showed that the program had significant effects on ego-resilience, peer relationships, happiness, interpersonal care awareness, physiological anxiety, and physiological stress. The findings suggest that interpersonal care nursing can be effective for children from multicultural families, and the program can be used for intervention to improve children's mental health.

"She Has the Japanese Style": Parenting by Japanese Immigrant Women in Korea from the Perspective of Their Children.

This study looks into the parenting beliefs and behavior of female Japanese immigrants, who have stayed in Korea for more than 20 years, and attempts to explore factors for their distinct parenting style compared to their Korean counterparts. In Korea and Japan, a mother's parenting is seen as crucial, while paternal responsibility is considered minimal. There are few studies that look into parenting patterns of Japanese immigrant women in Korea, especially from the perspective of their children. The study is based on in-depth interviews and participant observation in 2014 with 21 young Japanese-Korean adults recruited through snowball sampling. In raising children, the priorities of mothers were not academic but instead focused on children's autonomy, wholesome personality, religiosity, various life experiences, maintaining health, and non-intervention. The mothers' own cultural background and strong Japanese identity, limited interaction with Korean mothers or exclusive interaction with Japanese mothers, the role of the father figure as only a breadwinner, and mothers' strong devotion to church activities tend to influence their parenting. An exploration of the mechanisms behind the differences in their styles of parenting is important before judging their parenting to be improper or maladjusted. Understanding parenting styles of families from diverse backgrounds helps to understand what society will look like in the near future.

Relationship between the Developmental Coordination Disorder Questionnaire 2007 and the Bruininks-Oseretsky Test of Motor Proficiency Second Edition in Korean Children.

This study investigated the relationship between the Developmental Coordination Disorder Questionnaire 2007 (DCDQ'07) and the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2) in Korea. This study also adjusted the cutoff score of the DCDQ'07 based on the BOT-2 for Korean children. A total of 256 children were recruited from communities in Korea. They were divided into two age groups: 8 to 9 years old and 10 to 12 years old. Children performed the BOT-2, and their parents completed the DCDQ'07. The correlation between the DCDQ'07 and the BOT-2 was analyzed. The adjusted DCDQ'07 cutoff score for Korean children was calculated using the BOT-2 as the criterion through a receiver operating characteristic curve. A significant correlation between the DCDQ'07 and the BOT-2 was found, indicating that Korean parents' perception of children's motor skills was related to their children's actual motor proficiency. The adjusted cutoff score of the DCDQ'07 had a sensitivity of 72.7-85.7% and a specificity of 62.5-64.0%. This study demonstrated that children's motor skills reported by Korean parents on the DCDQ'07 were valid based on a community sample. The adjusted cutoff score of the DCDQ'07 could be used to identify children suspected of having a developmental coordination disorder.

Polymorphisms in the FKBP5 gene are associated with attention deficit and hyperactivity disorder in Korean children.

Attention deficit hyperactivity disorder (ADHD) is a common and heritable childhood psychiatric disorder. Recently, many studies reported a down-regulated hypothalamus-pituitary-adrenal axis (HPA-axis) with low cortisol levels in children with ADHD. The FK506 binding protein 5 or FKBP5 gene regulates the negative feedback of the HPA-axis, and genetic variants in this gene showed an association with ADHD. We investigated the genetic association between FKBP5 gene polymorphisms and susceptibility to ADHD in Korean children. We conducted a case-control study with 150 ADHD children and 322 controls. Genotyping of FKBP5 rs9394309 and rs7748266 was performed by using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). Our results showed that rs7748266 polymorphism has significant genotype (p = 0.021) and allele (p = 0.009) frequency differences between children with ADHD and the control group. CT genotype [odds ratio (OR) 1.70, 95 % confidence interval (CI) 1.134-2.540, p = 0.010] and T allele (OR 1.54, 95 % CI 1.114-2.117, p = 0.009) were associated with increased risk of ADHD. In addition, dominant (p = 0.006) and over-dominant genetic (p = 0.016) models showed significant associations with ADHD. In the stratified analysis, a significant result was obtained from the girl samples (p = 0.048). The OR of the girls with ADHD with CT genotype was 2.29 (95 % CI 1.170-4.469, p = 0.014). In contrast to rs7748266 polymorphism, rs9394309 polymorphism did not show any significant result (p > 0.05). Haplotype analysis also revealed a significant difference of the TG haplotype for rs7748266 - rs9394309 (p = 0.028, global haplotype association p-value of 0.0091). Conclusively, we confirmed that FKBP5 gene polymorphisms were associated with ADHD in Korean children. These results suggested that FKBP5 may factor in the development of ADHD.

The Reciprocal Longitudinal Relationship between Executive Dysfunction and Happiness in Korean Children.

The goal of this study was to examine the reciprocal longitudinal relationships between executive dysfunction and happiness for Korean children. We used data from the Panel Study of Korean Children (PSKC) conducted by the Korean Institute of Child Care and Education. A total of 1240 valid responses from the first to third grade in elementary school were analyzed using autoregressive crossed-lagged modeling. As a result, executive dysfunction and happiness were found to have reciprocal influences over the three time points. We also found that the cross-lagged effects of executive dysfunction and happiness were stronger than those of happiness on executive dysfunction. Clinical implications and limitations were discussed.

Low Body Mass Index Levels and Idiopathic Scoliosis in Korean Children: A Cross-Sectional Study.

BACKGROUND: The prevalence of idiopathic scoliosis is rapidly increasing in Korean children, but research on the disorder is limited compared to that in other countries. Accordingly, in the present study, we aimed to investigate the relationship between idiopathic scoliosis and body mass index (BMI) levels in Korean children. METHODS: This cross-sectional study enrolled elementary school students and middle school first graders in the Capital Area in Korea. The participants underwent body composition measurements and screening for idiopathic scoliosis. Idiopathic scoliosis was defined as a Cobb angle of ≥10°. The students were classified into three groups-the severely underweight (SUW: BMI < 16 kg/m2) group, the underweight group (UW: 16 ≤ BMI < 18.5 kg/m2), and the normal weight group (NW: 18.5 ≤ BMI < 25 kg/m2) to compare the risk of idiopathic scoliosis across BMI levels. RESULTS: The final cohort comprised 1375 participants. The odds ratio (OR) of idiopathic scoliosis was 0.69 (95% confidence interval (CI): 0.50-0.94) and 0.66 (95% CI: 0.49-0.89) for the UW and the NW groups, respectively, with the SUW group as the reference. This shows that the risk decreased significantly by 31% and 34% in the UW and the NW groups, respectively. After controlling for age and sex, the corresponding ORs were 0.72 (95% CI: 0.52-0.98) and 0.70 (95% CI: 0.51-0.96), and the risk significantly decreased by 28% and 30% in the UW and the NW groups, respectively. CONCLUSIONS: Low body weight is closely associated with spinal deformity and idiopathic scoliosis.

Developmental Trajectory of Inattention and Its Association With Depressive Symptoms in Adolescence: Peer Relationships as a Mediator.

This study investigated the developmental trajectory of inattention symptoms as a predictor of later depressive symptoms in adolescence, and examined potential mediating role of peer relationships in this process. Participants were adolescents who were part of the large longitudinal panel study on Korean Youths, Korean Children & Youth Panel Survey 2010 (KCYPS 2010) of the National Youth Policy Institute (NYPI). Specifically, data were drawn from two cohorts of KCYPS that differed in participant age (Panel 1: 2003 birth cohort, n = 2,342, 48.2% girls; Panel 2: 2000 birth cohorts, n = 2,378, 40.0% girls). We analyzed data collected from 2010 to 2016 when children in panel 1 were 6-7 to 12-13 years old, and children in panel 2 were 9-10 to 15-16 years old. Results of latent growth modeling (LGM) were as follows. In Panel 1, the inattention symptoms increased from 9-10 to 12-13 years. Otherwise, the inattention symptoms decreased from 11-12 to 15-16 years in panel 2. Additionally, in both panels, initial status and slope of inattention significantly predicted later levels of depressive symptoms, and peer relationships partly mediated the association between inattention trajectory and depressive symptoms. The findings are discussed with respect to considering the growth of inattention and the quality of peer relationships as promising targets for early identification and intervention of depression in adolescents.