title: Links between co-occurring social-communication and hyperactive-inattentive trait trajectories.
abstract: OBJECTIVE
  There is overlap between an autistic and hyperactive-inattentive symptomatology when studied cross-sectionally. This study is the first to examine the longitudinal pattern of association between social-communication deficits and hyperactive-inattentive symptoms in the general population, from childhood through adolescence. We explored the interrelationship between trajectories of co-occurring symptoms, and sought evidence for shared prenatal/perinatal risk factors.
  
  
  METHODS
  Study participants were 5,383 singletons of white ethnicity from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multiple measurements of hyperactive-inattentive traits (Strengths and Difficulties Questionnaire) and autistic social-communication impairment (Social Communication Disorder Checklist) were obtained between 4 and 17 years. Both traits and their trajectories were modeled in parallel using latent class growth analysis (LCGA). Trajectory membership was subsequently investigated with respect to prenatal/perinatal risk factors.
  
  
  RESULTS
  LCGA analysis revealed two distinct social-communication trajectories (persistently impaired versus low-risk) and four hyperactive-inattentive trait trajectories (persistently impaired, intermediate, childhood-limited and low-risk). Autistic symptoms were more stable than those of attention-deficit/hyperactivity disorder (ADHD) behaviors, which showed greater variability. Trajectories for both traits were strongly but not reciprocally interlinked, such that the majority of children with a persistent hyperactive-inattentive symptomatology also showed persistent social-communication deficits but not vice versa. Shared predictors, especially for trajectories of persistent impairment, were maternal smoking during the first trimester, which included familial effects, and a teenage pregnancy.
  
  
  CONCLUSIONS
  Our longitudinal study reveals that a complex relationship exists between social-communication and hyperactive-inattentive traits. Patterns of association change over time, with corresponding implications for removing exclusivity criteria for ASD and ADHD, as proposed for DSM-5.
authors.affiliation: Medical Research Council Centre for Causal Analysis in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, UK. Beate.StPourcain@bristol.ac.uk
authors.forename: Beate
authors.initials: B
authors.lastname: St Pourcain
authors.forename: William P
authors.initials: WP
authors.lastname: Mandy
authors.forename: Jon
authors.initials: J
authors.lastname: Heron
authors.forename: Jean
authors.initials: J
authors.lastname: Golding
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
authors.forename: David H
authors.initials: DH
authors.lastname: Skuse
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology* / Q000209:etiology; D002675:Child, Preschool; D003147:Communication Disorders / Q000453:epidemiology* / Q000209:etiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011253:Pregnancy in Adolescence; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires