Marie-Christine Brault

Heterogeneity of sex-stratified BMI trajectories in children from 8 to 14 years old.

OBJECTIVE Describe and predict sex-stratified trajectories of weight change in youths transitioning from childhood to adolescence. METHODS Using an accelerated longitudinal design, 461 children between 8 and 12 years old at baseline were followed over three years. Body mass index was calculated from self-reported height and weight. Latent class growth analysis was used to identify BMI trajectories and multinomial logistic regressions, to predict group membership. RESULTS A four-group heterogeneous trajectory model emerged for boys and girls alike. Characteristics of the trajectories differed between sexes and no obesity group was found for boys. Sociocultural factors, such as media influence, body dissatisfaction, weight victimization, awareness of thin-ideal standards and related pressures were important correlates of trajectory membership. CONCLUSION BMI trajectories during preadolescence are stable over time for heavier children. Body image concerns and weight stigmatization stand out as important factors in the prediction of developmental weight trajectories and could therefore be integrated in weight gain prevention programs for children of all weights as well as in weight management interventions for overweight and obese children.

Well-being, gender, and psychological health in school-aged children

BackgroundDespite being a well-documented phenomenon, gender differences in psychological health complaints in adolescence are poorly understood. The purpose of this study was to test factors related to well-being as explanatory factors of gender differences in psychological complaints (feeling low, irritability or bad temper, nervousness, and sleeping difficulties) in adolescence.MethodsThis study was based on the 9th Health Behaviour in School-aged Children (HBSC) study, conducted in 2010 in the Wallonia-Brussels Federation, Belgium, on 9–24 year olds. Using logistic regression analyses, we studied gender differences in psychological complaints through well-being factors (life satisfaction, self-confidence, helplessness, and body image), across age categories, and examined the variation of female excess after taking into account each factor.ResultsThe four well-being factors together explained more than half of the female excess in feeling low. However, there were still significant gender differences in feeling low for children over 13. Among 13 to 15-year-olds, there were no gender differences in irritability after adjustment. An important decrease in gender differences in nervousness was observed in the multivariate analyses, although there was still significant female excess in nervousness increasing from 13 years old. After full adjustment, only gender differences in sleeping difficulties among 13–15-year-olds remained significant. For all psychological complaints studied, self-confidence caused the most important decrease in gender difference.ConclusionsThis study showed that factors related to well-being could mediate the association between gender and psychological complaints, and pointed to the importance of taking into account well-being factors in the analyses of the aetiology of gender differences in psychological complaints. However, our results suggested that future research should explore additional explanations for gender differences in psychological complaints.

Witnessing violence in early secondary school predicts subsequent student impairment

Background Past research suggests that adolescents who witness violence are at risk of adjustment problems. However, few studies have implemented a longitudinal design and have accounted for direct experiences of victimisation and other major confounders. This prospective study examines the relationship between witnessing school violence and subsequent impairment and whether such associations depend on the kind of violence witnessed. Methods 3936 adolescents from Quebec (Canada) were followed from ages 12 through 15 years. Linear regression tested associations between witnessing school violence at age 13 and subsequent antisocial behaviour (drug use, delinquency), emotional distress (social anxiety, depressive symptoms) and academic adjustment (school achievement, engagement) at age 15. We compared the relative contribution of differing forms of witnessing school violence versus being victimised directly. Results General school violence predicted later impairment. The adjusted associations between indirectly experiencing violence as a bystander and subsequent impairment were comparable to those of direct victimisation. Witnessing covert and major violence was associated with drug use and delinquency. Witnessing minor violence was associated with increases in drug use, social anxiety, depressive symptoms and decreases in school engagement. Conclusions Almost all students witnessed school violence, which predicted impairment. Witnessing violence was associated with risk of subsequent adjustment problems 2 years later. Directly experienced victimisation showed a comparable magnitude of risk. This suggests that when it comes to symptoms of conduct disorder, witnessing violence might have the same impact as experiencing it directly. Witnessing earlier covert and major violence predicted social impairment whereas minor violence predicted psychological and academic impairment.