title: Comorbid Development of Disruptive Behaviors from age 1½ to 5 Years in a Population Birth-Cohort and Association with School Adjustment in First Grade.
abstract: Comorbidity is frequent among disruptive behaviors (DB) and leads to mental health problems during adolescence and adulthood. However, the early developmental origins of this comorbidity have so far received little attention. This study investigated the developmental comorbidity of three DB categories during early childhood: hyperactivity-impulsivity, non-compliance, and physical aggression. Joint developmental trajectories of DB were identified based on annual mother interviews from age 1½ to 5 years, in a population-representative birth-cohort (N = 2045). A significant proportion of children (13 % to 21 %, depending on the type of DB) consistently displayed high levels of hyperactivity-impulsivity, non-compliance, or physical aggression from age 1½ to 5 years. Developmental comorbidity was frequent, especially for boys: 10 % of boys and 3.7 % of girls were on a stable trajectory with high levels of symptoms for the three categories of DB. Significant associations were observed between preschool joint-trajectories of DB and indicators of DB and school adjustment assessed by teachers in first grade. Preschoolers who maintained high levels of hyperactivity-impulsivity, non-compliance, and physical aggression, displayed the highest number of DB symptoms in first grade for all categories according to their teacher. They were also among the most disadvantaged of their class for school adjustment indicators. Thus, DB manifestations and developmental comorbidity of DB are highly prevalent in infancy. Early childhood appears to be a critical period to prevent persistent and comorbid DB that leads to impairment at the very beginning of school attendance and to long-term serious health and social adjustment problems.
authors: Department of Pediatrics, Faculty of Medicine, University of Montreal, 3050 Edouard-Montpetit, suite 225, Montréal, QC, H3T 1J7, Canada. rene.carbonneau@umontreal.ca.|Sainte-Justine Hospital Research Center, Montreal, QC, Canada. rene.carbonneau@umontreal.ca.|Research Unit on Children's Psychosocial Maladjustment, University of Montreal, Montreal, QC, Canada. rene.carbonneau@umontreal.ca.
authors: Rene
authors: R
authors: Carbonneau
authors: Research Unit on Children's Psychosocial Maladjustment, University of Montreal, Montreal, QC, Canada.|Department of Psychology, Laval University, Quebec, QC, Canada.|Institute of Genetic, Neurobiological, and Social Foundations of Child Development, Tomsk State University, Tomsk, Russian Federation.
authors: Michel
authors: M
authors: Boivin
authors: Sainte-Justine Hospital Research Center, Montreal, QC, Canada.|Research Unit on Children's Psychosocial Maladjustment, University of Montreal, Montreal, QC, Canada.|Department of Psychology, University of Quebec in Montreal, Montreal, QC, Canada.
authors: Mara
authors: M
authors: Brendgen
authors: Department of Public Policy and Statistics, Carnegie Mellon University, Pittsburgh, PA, USA.
authors: Daniel
authors: D
authors: Nagin
authors: Sainte-Justine Hospital Research Center, Montreal, QC, Canada.|Research Unit on Children's Psychosocial Maladjustment, University of Montreal, Montreal, QC, Canada.|Institute of Genetic, Neurobiological, and Social Foundations of Child Development, Tomsk State University, Tomsk, Russian Federation.|School of Public Health and Population Sciences, University College Dublin, Dublin, Ireland.
authors: Richard E
authors: RE
authors: Tremblay
mesh_terms: D000374:Aggression / Q000502:physiology*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D002652:Child Behavior / Q000502:physiology*; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*; D008297:Male; D011792:Quebec / Q000453:epidemiology; D012574:Schools; D012917:Social Adjustment
keywords: Comorbidity; Disruptive behaviors; Preschool years; School entry; Trajectories