title: Blunted cortisol responses to stress signal social and behavioral problems among maltreated/bullied 12-year-old children.
abstract: BACKGROUND
  Evidence from animal and human studies suggests that early-life stress such as physical maltreatment has long-lasting effects on the hypothalamic-pituitary-adrenal (HPA) axis and is associated with blunted HPA axis reactivity in adulthood. Few studies have investigated whether blunted HPA axis reactivity observed in children exposed to early-life stress signals social, emotional, and behavioral problems.
  
  
  METHODS
  Participants were 190 12-year-old children (50.5% males) recruited from the Environmental Risk Longitudinal Twin Study, a nationally representative 1994 to 1995 cohort of families with twins. Cortisol responses to psychosocial stress were measured in maltreated/bullied (n = 64) and comparison children (n = 126). We ascertained maltreatment and bullying victimization using mothers' reports and assessed children's social, emotional, and behavioral problems at ages 5 and 12 using mothers' and teachers' reports.
  
  
  RESULTS
  Piecewise multilevel growth curve analyses indicated that maltreated/bullied and comparison children showed distinct cortisol responses to stress. Specifically, maltreated/bullied children had lower cortisol responses than comparison children who exhibited a significant increase. Lower cortisol responses were, in turn, associated with more social and behavioral problems among maltreated/bullied children.
  
  
  CONCLUSIONS
  These findings provide support for the influence of childhood harm on blunted HPA axis reactivity and its potential impact on children's functioning. Our findings emphasize the need to integrate stress biomarkers in guiding prevention efforts for young victims.
authors.affiliation: Medical Research Council Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, United Kingdom.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ouellet-Morin
authors.forename: Candice L
authors.initials: CL
authors.lastname: Odgers
authors.forename: Andrea
authors.initials: A
authors.lastname: Danese
authors.forename: Lucy
authors.initials: L
authors.lastname: Bowes
authors.forename: Sania
authors.initials: S
authors.lastname: Shakoor
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Papadopoulos
authors.forename: Avshalom
authors.initials: A
authors.lastname: Caspi
authors.forename: Terrie E
authors.initials: TE
authors.lastname: Moffitt
authors.forename: Louise
authors.initials: L
authors.lastname: Arseneault
mesh_terms: D002648:Child; D002649:Child Abuse / Q000523:psychology*; D002653:Child Behavior Disorders / Q000097:blood* / Q000209:etiology*; D015331:Cohort Studies; D004644:Emotions / Q000502:physiology; D005192:Family Health; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007118:Immunoassay / Q000379:methods; D008297:Male; D008960:Models, Psychological; D012307:Risk Factors; D012720:Severity of Illness Index; D013315:Stress, Psychological / Q000150:complications*
chemical_list: D006854:Hydrocortisone