Évolution des caractéristiques, des déterminants et des répercussions du sommeil chez le jeune enfant

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Early childhood trajectories of separation anxiety : bearing on mental health, academic achievement, and physical health from mid‐childhood to preadolescence

1 Background Separation anxiety disorder is the most prevalent childhood anxiety condition, but no study assessed children for separation anxiety at preschool age and followed them longitudinally and directly until mid‐childhood/early adolescence. 2 Methods Multi‐informant (children, teachers, family), multipoint (at age 8, 10, 12, 13) assessments of 1,290 children of the Quebec Longitudinal Study of Child Development, who had been categorized between age 1.5 and 6 into four specific separation anxiety trajectories (1, low‐persistent; 2, low‐increasing; 3, high‐decreasing, and the less common: 4, high‐increasing) by growth mixture modeling. Participants in the high‐increasing trajectory were compared to participants in the other three trajectories for: (a) child's internalizing and externalizing problem behavior; (b) physical health; (c) academic achievement; (d) maternal anxiety. 3 Results Multivariate analyses of variance/covariance at separate time points showed the high‐increasing trajectory mostly associated with: (a) higher internalizing, but not externalizing, behavior; (b) worse academic achievement (most consistently by comparisons to the normative low‐persistent trajectory; (c) higher rates of maternal panic/agoraphobic anxiety; (d) worse physical health (most consistently by comparisons to the low‐persistent trajectory). The high‐increasing trajectory had twofold to threefold higher incidences of physical illnesses than the normative low‐persistent group; this was specific for headaches at age 12 years, chronic asthma at age 10 and 13, and having received asthma‐related medication during the past 12 months. 4 Conclusions High‐increasing separation anxiety in preschool maintains longitudinal relationships to independent health and academic outcomes, at least until preadolescence. This knowledge can inform the deployment of clinical resources at the earlier signs of the more impairing manifestations

Distinct trajectories of separation anxiety in the preschool years: persistence at school entry and early-life associated factors

Background: Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their early associated risk factors, and their associations with teachers’ ratings of SA in kindergarten. Methods: Longitudinal assessment of SA trajectories and risk factors in a cohort of 1933 families between the ages of 1.5 and 6 years. Results: Analyses revealed a best-fitting, 4-trajectory solution, including a prevailing, unaffected Low-Persistent group (60.2%), and 3 smaller groups of distinct developmental course: a High-Increasing (6.9%), a High-Decreasing (10.8%) and a Low-Increasing group (22.1%). The High-Increasing group remained high throughout the preschool years and was the only trajectory linked to teacher-assessed SA in kindergarten. Except for the High-Increasing, all trajectories showed substantial reduction of symptom profile by age 6. The High-Increasing and High-Decreasing groups shared several early risk factors, but the former was uniquely associated with higher maternal depression, maternal smoking during pregnancy, and parental unemployment. Conclusions: Most children with high SA profile at age 1.5 years are expected to progressively recover by age 4-5. High SA at age 1.5 that persists over time deserves special attention, and may predict separation anxiety disorder. A host of child perinatal, parental, and family contextual risk factors were associated with the onset and developmental course of SA across the preschool years

Early risk factors of overweight developmental trajectories during middle childhood

Background Research is needed to identify early life risk factors associated with different developmental paths leading to overweight by adolescence. Objectives To model heterogeneity in overweight development during middle childhood and identify factors associated with differing overweight trajectories. Methods Data was drawn from the Quebec Longitudinal Study of Child Development (QLSCD; 1998- 2010). Trained research assistants measured height and weight according to a standardized protocol and conducted yearly home interviews with the child’s caregiver (mother in 98% of cases). Information on several putative early life risk factors for the development of overweight were obtained, including factors related to the child’s perinatal, early behavioral family and social environment. Group-based trajectories of the probability of overweight (6- 12 years) were identified with a semiparametric method (n=1678). Logistic regression analyses were used to identify early risk factors (5 months- 5 years) associated with each trajectory. Results Three trajectories of overweight were identified: “early-onset overweight” (11.0 %), “lateonset overweight” (16.6%) and “never overweight” (72.5%). Multinomial analyses indicated that children in the early and late-onset group, compared to the never overweight group, had 3 common types of risk factors: parental overweight, preschool overweight history, and large size for gestational age. Maternal overprotection (OR= 1.12, CI: 1.01-1.25), short nighttime sleep duration (OR=1.66, CI: 1.07-2.57), and immigrant status (OR=2.01, CI: 1.05-3.84) were factors specific to the early-onset group. Finally, family food insufficiency (OR=1.81, CI: 1.00-3.28) was weakly associated with membership in the late-onset trajectory group. Conclusions The development of overweight in childhood follows two different trajectories, which have common and distinct risk factors that could be the target of early preventive interventions

Development and aetiology of body dissatisfaction in adolescent boys and girls

This longitudinal study aims to describe the development of body dissatisfaction (BD), measured with the Contour Drawing Rating Scale, between the ages of 14 and 18, and to identify factors associated with BD at age 18, among 413 adolescents. Between the ages of 14 and 18, the proportion of girls wanting to be thinner increased, although it remained unchanged among boys. A ratio of 1:2 girls and 1:5 boys reported having seriously tried to lose weight. Factors associated with BD in girls at age 18 were (1) wanting to be thinner, (2) body mass index (BMI), (3) weight control behaviours and (4) negative comments about weight. Factors associated with BD in boys at age 18 were (1) wanting to be thinner or bigger, (2) BMI, (3) having experienced sexual intercourse and (4) negative comments about weight. The high prevalence of BD and weight-related concerns suggest a need for early interventions

Distinct trajectories of separation anxiety in the preschool years: persistence at school entry and early-life associated factors

Backgroun