ABSTRACT BACKGROUND Exposure to peer victimization is relatively common. However, little is known about its developmental course and its effect on impairment associated with mental illnesses. We ...aimed to identify groups of children following differential trajectories of peer victimization from ages 6 to 13 years and to examine predictive associations of these trajectories with mental health in adolescence. METHODS Participants were members of the Quebec Longitudinal Study of Child Development, a prospective cohort of 2120 children born in 1997/98 who were followed until age 15 years. We included 1363 participants with self-reported victimization from ages 6 to 13 years and data available on their mental health status at 15 years. RESULTS We identified 3 trajectories of peer victimization. The 2 prevailing groups were participants with little or moderate exposure to victimization (441/1685 26.2% and 1000/1685 59.3%, respectively); the third group (244 14.5%) had been chronically exposed to the most severe and long-lasting levels of victimization. The most severely victimized individuals had greater odds of reporting debilitating depressive or dysthymic symptoms (odds ratio OR 2.56, 95% confidence interval CI 1.27–5.17), debilitating generalized anxiety problems (OR 3.27, CI 1.64–6.51) and suicidality (OR 3.46, CI 1.53–7.81) at 15 years than those exposed to the lowest levels of victimization, after adjustment for sex, childhood mental health, family hardship and victimization perpetration. The association with suicidality remained significant after controlling for concurrent symptoms of depression or dysthymia and generalized anxiety problems. INTERPRETATION Adolescents who were most severely victimized by peers had an increased risk of experiencing severe symptoms consistent with mental health problems. Given that peer victimization trajectories are established early on, interventions to reduce the risk of being victimized should start before enrolment in the formal school system.
To test whether adolescents who are victimized by peers are at heightened risk for suicidal ideation and suicide attempt, using both cross-sectional and prospective investigations.
Participants are ...from the Quebec Longitudinal Study of Child Development, a general population sample of children born in Quebec in 1997 through 1998 and followed up until 15 years of age. Information about victimization and serious suicidal ideation and suicide attempt in the past year was obtained at ages 13 and 15 years from self-reports (N = 1,168).
Victims reported concurrently higher rates of suicidal ideation at age 13 years (11.6-14.7%) and suicide attempt at age 15 years (5.4-6.8%) compared to those who had not been victimized (2.7-4.1% for suicidal ideation and 1.6-1.9% for suicide attempt). Being victimized by peers at 13 years predicted suicidal ideation (odds ratio OR = 2.27; 95% CI = 1.25-4.12) and suicide attempt (OR = 3.05, 95% CI = 1.36-6.82) 2 years later, even after adjusting for baseline suicidality and mental health problems and a series of confounders (socioeconomic status, intelligence, family's functioning and structure, hostile-reactive parenting, maternal lifetime suicidal ideation/suicide attempt). Those who were victimized at both 13 and 15 years had the highest risk of suicidal ideation (OR = 5.41, 95% CI = 2.53-11.53) and suicide attempt (OR = 5.85, 95% CI = 2.12-16.18) at 15 years.
Victimization is associated with an increased risk of suicidal ideation and suicide attempt over and above concurrent suicidality and prior mental health problems. The longer the history of victimization, the greater the risk.
Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the ...transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status, socioeconomic status, the parent-child relationship) predictors. Peer victimization was assessed via self-reports from Grades 4 through 9 (ages 10 through 15 years), aggression and internalizing problems were assessed in Grade 4 via peer nominations, and the parent-child relationship was assessed in Grade 7 (i.e., right after the transition to secondary school) via parent-reports. Growth Mixture modeling revealed 1 group (62%) who experienced little victimization in primary school and even less in secondary school, another group (31%) who was victimized in primary but not or much less in secondary school, and a third group (7%) who was chronically victimized in both school contexts. Boys were more likely than girls to follow any elevated victimization trajectory. Chronic victimization across primary and secondary school was predicted by nonintact family status and a combination of both internalizing problems and aggression compared with nonvictimized youth. In contrast, transitory victimization during primary but not in secondary school was predicted by aggression, but not internalizing problems. Support as well as conflict in the parent-child relationship also showed significant, albeit distinct associations with the different peer victimization trajectories.
Defective intestinal epithelial tight junction (TJ) barrier has been shown to be a pathogenic factor in the development of intestinal inflammation. Interleukin-6 (IL-6) is a pleiotropic, ...pro-inflammatory cytokine which plays an important role in promoting inflammatory response in the gut and in the systemic circulation. Despite its key role in mediating variety inflammatory response, the effect of IL-6 on intestinal epithelial barrier remains unclear. The purpose of this study was to investigate the effect of IL-6 on intestinal epithelial TJ barrier and to delineate the intracellular mechanisms involved using in-vitro (filter-grown Caco-2 monolayers) and in-vivo model (mouse intestinal perfusion) systems. Our results indicated that IL-6 causes a site-selective increase in Caco-2 intestinal epithelia TJ permeability, causing an increase in flux of small-sized molecules having molecular radius <4 Å. The size-selective increase in Caco-2 TJ permeability was regulated by protein-specific increase in claudin-2 expression. The IL-6 increase in TJ permeability required activation of JNK signaling cascade. The JNK pathway activation of AP-1 resulted in AP-1 binding to its binding sequence on the claudin-2 promoter region, leading to promoter activation and subsequent increase in claudin-2 gene transcription and protein synthesis and TJ permeability. Our in-vivo mouse perfusion showed that IL-6 modulation of mouse intestinal permeability was also mediated by AP-1 dependent increase in claudin-2 expression. In conclusion, our studies show for the first time that the IL-6 modulation of intestinal TJ permeability was regulated by JNK activation of AP-1 and AP-1 activation of claudin-2 gene.
Eating behaviors may contribute to differences in body weight and diet over time. Our study aims to examine how eating behaviors of young adults relate to their current weight status and dietary ...patterns and to explore longitudinal associations with eating behaviors in early childhood. Study participants are young adults (n = 698) taking part in the Quebec Longitudinal Study of Child Development. At age 22, eating behaviors were assessed using the Adult Eating Behavior Questionnaire. Dietary patterns were derived from information collected by food frequency questions. Weight status was based on self-reported data. Information on eating behaviors in childhood had been collected when participants were 2.5 to 6 years old. Pearson's correlations were used to determine associations between adult eating behaviors and body mass index. Simple and multivariate linear regression analyses were used to examine associations between eating behaviors and dietary patterns at age 22, and longitudinal associations with behaviors in early childhood. Ordinal logistic regression analyses were used to assess associations between overeating and fussy eating in childhood and weight status at age 22. Body mass index was positively correlated with Emotional overeating, Enjoyment of food, and Food responsiveness and negatively correlated with Satiety responsiveness, Emotional undereating, Slowness in eating and Hunger. A Healthy dietary pattern was positively associated with both Enjoyment of food and Hunger, and negatively associated with Food fussiness. Inversely, a Beverage-rich dietary pattern was negatively associated with Enjoyment of food and positively associated with Food fussiness. A Protein-rich pattern was positively associated with Enjoyment of food, while a High energy density pattern was positively associated with Food fussiness. Young adults with higher scores for fussy eating in early childhood were more likely to manifest Food fussiness and Emotional undereating, and less likely to adopt a Healthy dietary pattern. Young adults with higher scores for overeating in early childhood were less likely to show traits such as Slowness in eating and more likely to be overweight. Our findings suggest that eating behaviors in childhood have long-term influence on diet and weight status, thereby reinforcing the importance of early interventions that promote healthy eating.
This longitudinal study was aimed to describe and understand student adjustment trajectories during the college transition. Participants came from a large random sample of Quebec high school ...students. They completed a multidimensional measure of adjustment at two times before entering college and at two other times after college admission. Group-based trajectory analysis showed decreased adjustment for 6% (social adjustment) to 66.1% (academic adjustment) of students over this period, versus improved adjustment for 4.5% (social adjustment) to 11.6% (emotional and academic adjustment). All changes were linear, suggesting progressive changes from Secondary 4 to the second year of college. Multivariate and contingency analyses showed that personal anxiety, academic success, and attention problems in high school were significant determinants for adjustment trajectories, and that these trajectories were subsequently related to perseverance and college graduation.
Food insecurity (which can be defined as inadequate access to sufficient, safe, and nutritious food that meets individuals' dietary needs) is concurrently associated with children's psychological ...difficulties. However, the predictive role of food insecurity with regard to specific types of children's mental health symptoms has not previously been studied. We used data from the Longitudinal Study of Child Development in Québec, LSCDQ, a representative birth cohort study of children born in the Québec region, in Canada, in 1997-1998 (n = 2120). Family food insecurity was ascertained when children were 1½ and 4½ years old. Children's mental health symptoms were assessed longitudinally using validated measures of behaviour at ages 4½, 5, 6 and 8 years. Symptom trajectory groups were estimated to identify children with persistently high levels of depression/anxiety (21.0%), aggression (26.2%), and hyperactivity/inattention (6.0%). The prevalence of food insecurity in the study was 5.9%. In sex-adjusted analyses, children from food-insecure families were disproportionately likely to experience persistent symptoms of depression/anxiety (OR: 1.79, 95% CI 1.15-2.79) and hyperactivity/inattention (OR: 3.06, 95% CI 1.68-5.55). After controlling for immigrant status, family structure, maternal age at child's birth, family income, maternal and paternal education, prenatal tobacco exposure, maternal and paternal depression and negative parenting, only persistent hyperactivity/inattention remained associated with food insecurity (fully adjusted OR: 2.65, 95% CI 1.16-6.06). Family food insecurity predicts high levels of children's mental health symptoms, particularly hyperactivity/inattention. Addressing food insecurity and associated problems in families could help reduce the burden of mental health problems in children and reduce social inequalities in development.
This study explored whether early elementary school aged children's externalizing problems impede academic functioning and foster negative social experiences such as peer victimization, thereby ...making these children vulnerable for developing internalizing problems and possibly increasing their externalizing problems. It also explored whether early internalizing problems contributed to an increase in externalizing problems. The study examined 1,558 Canadian children from ages 6 to 8 years. Externalizing and internalizing problems, peer victimization, and school achievement were assessed annually. Externalizing problems lead to academic underachievement and experiences of peer victimization. Academic underachievement and peer victimization, in turn, predicted increases in internalizing problems and in externalizing problems. These pathways applied equally to boys and girls. No links from internalizing to externalizing problems were found.
To examine how food insecurity in childhood up to adolescence relates to eating habits and weight status in young adulthood.
A longitudinal study design was used to derive trajectories of household ...food insecurity from age 4·5 to 13 years. Multivariable linear and logistical regression analyses were performed to model associations between being at high risk of food insecurity from age 4·5 to 13 years and both dietary and weight outcomes at age 22 years.
A birth cohort study conducted in the Province of Quebec, Canada.
In total, 698 young adults participating in the Québec Longitudinal Study of Child Development.
After adjusting for sex, maternal education and immigrant status, household income and type of family, being at high risk (compared with low risk) of food insecurity in childhood up to adolescence was associated with consuming higher quantities of sugar-sweetened beverages (
: 0·64; 95 % CI (0·27, 1·00)), non-whole-grain cereal products (
: 0·32; 95 % CI (0·07, 0·56)) and processed meat (
: 0·14; 95 % CI (0·02, 0·25)), with skipping breakfast (OR
: 1·97; 95 % CI (1·08, 3·53)), with eating meals prepared out of home (OR
: 3·38; 95 % CI (1·52, 9·02)), with experiencing food insecurity (OR
: 3·03; 95 % CI (1·91, 4·76)) and with being obese (OR
: 2·01; 95 % CI (1·12, 3·64)), once reaching young adulthood.
Growing up in families experiencing food insecurity may negatively influence eating habits and weight status later in life. Our findings reinforce the importance of public health policies and programmes tackling poverty and food insecurity, particularly for families with young children.
Lead exposure predicts altered neurodevelopment and lower intelligence quotient (IQ) in children, but few studies have examined this association in children who have relatively low blood lead ...concentrations.
To test the associations between blood lead concentrations and cognitive function in Canadian preschoolers, with a possible moderation by sex.
The data were gathered from 609 mother-child pairs from the Maternal–Infant Research on Environmental Chemicals (MIREC) Study. Lead was measured in umbilical and maternal blood, and in children's venous blood at age 3–4 years. Cognitive function was measured with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) at 3–4 years. We tested the relationship between WPPSI-III scores and blood lead concentrations with multiple linear regression, adding child sex as a moderator.
Median blood lead concentrations for the mother at 1st trimester and 3rd trimester of pregnancy, and for cord and child blood were 0.60 μg/dL, 0.58 μg/dL, 0.79 μg/dL and 0.67 μg/dL, respectively. We found no association between cord blood lead concentrations and WPPSI-III scores in multivariable analyses. However, cord blood lead concentrations showed a negative association with Performance IQ in boys but not in girls (B = 3.44; SE = 1.62; 95% CI: 0.82, 5.98). No associations were found between WPPSI-III scores and prenatal maternal blood or concurrent child blood lead concentrations.
Prenatal blood lead concentrations below 5 μg/dL were still associated with a decline in cognitive function in this Canadian cohort, but only for boys.
•Cord blood lead concentration was associated with lower Performance IQ in boys.•Concurrent child blood lead concentrations were not associated with children's IQ.•Canadian children from middle/upper class families are exposed to low lead levels.
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