Disregard for rules: the early development and predictors of a specific dimension of disruptive behavior disorders.

Background: Disregard for rules, an important dimension of oppositional defiant and conduct disorders, is frequent during early childhood, but the development of its chronic form has not been studied during this key socialization period. This study aimed to describe the developmental trajectories of disregard for rules during early childhood and identify prenatal and postnatal predictors for a high trajectory.

Methods: Participants were involved in a longitudinal study of a birth cohort followed yearly from 5 to 74 months of age (N = 1,942).

Depression and anxiety symptoms: onset, developmental course and risk factors during early childhood.

Background: Depressive and anxiety disorders are among the top ten leading causes of disabilities. We know little, however, about the onset, developmental course and early risk factors for depressive and anxiety symptoms (DAS).

Objective: Model the developmental trajectories of DAS during early childhood and to identify risk factors for atypically high DAS.

Physical aggression during early childhood: trajectories and predictors.

Introduction: This study aimed to identify the trajectories of physical aggression during early childhood and antecedents of high levels of physical aggression early in life.

Methods: 572 families with a 5-month-old newborn were recruited. Assessments of physical aggression frequency were obtained from mothers at 17, 30, and 42 months after birth.

[Prevalence and co-occurrence of five types of ill-treatment in relation with depression and conduct disorder in adolescent mothers].

In this article, the authors reflect on co-occurrence of different types of maltreatment that adolescent mothers have suffered during their childhood in order to better understand intergenerational transmission of maltreatment. They underline that studies on maltreatment that adults or adolescents have been subjected to during their childhood generally do not take into account co-occurrence of different types of maltreatment. The authors first attempt to verify if adolescent mothers are different from women of the general population in regards to prevalence and co-occurrence of various types of maltreatment suffered during their own development.

Maternal prenatal smoking, parental antisocial behavior, and early childhood physical aggression.

This study investigated joint effects of maternal prenatal smoking and parental history of antisocial behavior on physical aggression between ages 17 and 42 months in a population sample of children born in Québec (N = 1,745). An analysis of variance (ANOVA) showed significant main effects of maternal prenatal smoking and a significant interaction between maternal prenatal smoking and mother's history of antisocial behavior in the prediction of children's probability to display high and rising physical aggression. The interaction indicated that the effects of heavy smoking during pregnancy (> or =10 cigarettes/day) were greater when the mother also had a serious history of antisocial behavior.

Controlling parenting and physical aggression during elementary school.

The goal of the present study was to examine whether controlling parenting contributes to the problem of physical aggression. Developmental trajectories of children's physical aggression were modeled from yearly teachers' ratings, from ages 6 to 12. Multinomial logistic regressions (N = 1,508) served to identify risk factors that distinguish children who display different levels of physical aggression throughout grade school.

Girls' hyperactivity and physical aggression during childhood and adjustment problems in early adulthood: a 15-year longitudinal study.

Context: The co-occurrence of hyperactivity and conduct problems in childhood seems to increase the risk of early adulthood adjustment problems in males. However, little is known about this topic in females.

Objectives: To describe the joint developmental trajectories of female hyperactivity and physical aggression during childhood and to examine the extent to which high trajectories of hyperactivity and physical aggression predict adjustment problems in early adulthood.

The role of maternal education and nonmaternal care services in the prevention of children's physical aggression problems.

Context: Physical violence is an important health problem, and low maternal education is a significant risk for the development of chronic physical aggression (PA). We hypothesized that nonmaternal care (NMC) services could prevent the development of childhood PA problems, depending on the age at which the services are initiated. Method Children who followed a trajectory of atypically frequent PA between 17 and 60 months of age among a population sample of 1691 Canadian families were identified.

The association of major depression, conduct disorder, and maternal overcontrol with a failure to show a cortisol buffered response in 4-month-old infants of teenage mothers.

Background: Adolescent pregnancy can be associated with major depression (MD) and conduct disorder (CD). Some infants of adolescent mothers are prenatally exposed to these factors, which may result in heightened risk for perturbations of their stress systems. Between 2 and 4 months, a normal shift occurs in the adrenocortical system in which we observe a marked decrease in infant cortisol response when facing mild stressors.

Associations of maternal prenatal smoking with early childhood physical aggression, hyperactivity-impulsivity, and their co-occurrence.

This study investigated associations between maternal prenatal smoking and physical aggression (PA), hyperactivity-impulsivity (HI) and co-occurring PA and HI between ages 17 and 42 months in a population sample of children born in Québec (Canada) in 1997/1998 (N=1745). Trajectory model estimation showed three distinct developmental patterns for PA and four for HI. Multinomial regression analyses showed that prenatal smoking significantly predicted children's likelihood to follow different PA trajectories beyond the effects of other perinatal factors, parental psychopathology, family functioning and parenting, and socio-economic factors.

The evolution of problem and social competence behaviors during toddlerhood: A prospective population-based cohort survey.

Research in developmental psychopathology has long been preoccupied with rather broad categories of behavior, but we know little about the specific behaviors that comprise these categories. The objective of this study was to: (a) estimate the prevalence of problem and social competence behaviors in the general population of children at 17 months of age, and (b) describe the continuity and discontinuity in the degree to which children exhibit these behaviors between 17 and 29 months of age. The results show that frequent problem behaviors are not typical of children under two years of age.

Histories of child maltreatment and psychiatric disorder in pregnant adolescents.

Objective: The study investigated histories of child maltreatment and psychiatric disorder in a high-risk sample of pregnant adolescents.

Method: Cross-sectional data were obtained for 252 pregnant adolescents from high school, hospital, and group home settings in Montreal (Canada). Adolescents completed a child maltreatment questionnaire and a psychiatric interview on lifetime conduct and major depressive disorders.

Construct validity of an instrument to assess major depression in parents in epidemiologic studies.

Objective: The Longitudinal Study of Child Development in Quebec (LSCDQ) is a community study of children that examines the risk factors, such as parental depression, linked to childhood psychopathology and maladaptive functioning. Our goal was to test the construct validity of an instrument to assess major depression in the parents.

Method: Parents of a representative sample of 2120 infants born in the province of Quebec in 1998 were selected.

Sex and informant effects on diagnostic comorbidity in an adolescent community sample.

Objective: To investigate sex and informant effects on comorbidity rates for anxiety disorders, depressive disorders, attention-deficit hyperactivity disorder (ADHD), and conduct-oppositional disorder (CD-ODD) in an adolescent community sample.

Method: The Diagnostic Interview Schedule for Children-2.25 (DISC-2.

The genetic-environmental etiology of parents' perceptions and self-assessed behaviours toward their 5-month-old infants in a large twin and singleton sample.

Background: Given the importance of parenting for the child's early socio-emotional development, parenting perceptions and behaviours, and their correlates, should be assessed as early as possible in the child's life. The goals of the present study were 1) to confirm, in two parallel population-based samples, including a large sample of twins, the factor structure of a new self-administered questionnaire assessing both parents' specific parenting perceptions and behaviours toward their 5-month-old infants (i.e.

Individual change in methylphenidate use in a national sample of children aged 2 to 11 years.

Objectives: To determine methylphenidate use in children aged 2 to 13 years. To provide age- and sex-specific estimates of methylphenidate initiation and cessation during a 2-year period.

Method: Data from 2 cycles of a Canadian household survey yielded a sample of over 10 000 children aged 2 to 11 years at Cycle 1 who continued to participate at Cycle 2.

A new look at inter-informant agreement on conduct disorder using a latent class approach.

This study examined agreement on aggressive and nonaggressive conduct disorder in a general population sample of 14- to 17-year-old adolescents (n=1165) and their mothers. We collected diagnostic interview data and applied latent class analyses to estimate inter-informant agreement. The preferred model for aggressive conduct disorder for both males and females was a one-latent-variable/two-class model specifying no inter-informant disagreement beyond chance expectations.

[Validation of the French version of the CTQ and prevalence of the history of maltreatment].

This study demonstrates that the five maltreatment scales in the long and short versions of the CTQ are valid and usable with French-speaking populations. It also shows emotional neglect to be the most common form of maltreatment in its general population sample, and physical neglect to be the least common. Physical, emotional and sexual abuse prevalences in the convenience sample roughly correspond to the rates generally obtained in non-clinical samples.

Cortisol levels and conduct disorder in adolescent mothers.

Objective: To examine the association between cortisol levels and conduct disorder (CD) in adolescent mothers. Past research has shown that low levels of cortisol were associated with CD, particularly with its aggressive symptoms. The authors tested the hypothesis that adolescent mothers with CD would show lower levels of salivary cortisol compared to mothers without CD at 4 and 9 months postpartum.

Childhood behavioral profiles leading to adolescent conduct disorder: risk trajectories for boys and girls.

Objective: To examine the link between childhood behavioral dimensions and adolescent conduct disorder (CD) among a large sample of boys and girls monitored longitudinally.

Method: Teachers rated the behaviors of 1,569 children every year between kindergarten and grade 6. On the basis of these seven yearly ratings, groups of children who followed distinct trajectories on three behavioral dimensions--hyperactivity, fearfulness, and helpfulness--were identified with a semiparametric statistical analysis.

The development of impulsivity, fearfulness, and helpfulness during childhood: patterns of consistency and change in the trajectories of boys and girls.

Background: The objective of the present study was to describe the development of boys and girls during the elementary-school years on three dimensions that conceptually and empirically represent risk for maladjustment.

Method: Every year between kindergarten and grade six, teachers rated the impulsivity, fearfulness, and helpfulness dimensions among a sample of 1,865 children representative of kindergarten boys and girls in the province of Quebec (Canada) in 1986-87. A group-based trajectory method was used to 1) identify groups of boys and girls following distinct-level trajectories of behaviours (on each dimension) during the elementary-school years; 2) estimate the proportion of children in each of the identified trajectory groups; and 3) estimate the patterns of consistency and variations in trajectories.