title: Associations between postpartum depressive symptoms and childhood asthma diminish with child age.
abstract: BACKGROUND
  Affecting 19% of women, postpartum depression is a major concern to the immediate health of mothers and infants. In the long-term, it has been linked to the development of early-onset asthma at school entry, but only if the depression persists beyond the postnatal period. No studies have tested whether associations with postpartum depressive symptoms and early-onset asthma phenotypes persist into later school age.
  
  
  OBJECTIVE
  To determine associations between maternal postpartum depressive symptoms and childhood asthma between the ages of 5-10 by using a nested longitudinal design.
  
  
  METHODS
  Data were drawn from the 1994-2004 administrations of the Canadian National Longitudinal Survey of Children and Youth, which tracks the health of a nationally representative sample of children in Canada. Child asthma was diagnosed by a health professional, and maternal depressive symptoms were assessed by the Centre for Epidemiological Studies Depression scale. Analyses were conducted by using a multilevel modelling approach, in which longitudinal assessments of asthma in 1696 children were nested within the exposure of postpartum depression.
  
  
  RESULTS
  Postpartum depressive symptoms had a 1.5-fold significant association with childhood asthma between the ages 6-8. This was independent of male sex, maternal asthma, non-immigrant status, low household socioeconomic status, being firstborn, low birthweight, low family functioning and urban-rural residence, of which the first 4 covariates elevated the risk of asthma. Statistical significance was lost at age 8 when maternal prenatal smoking replaced urban-rural residence as a covariate. At ages 9-10, an association was no longer evident.
  
  
  CONCLUSIONS
  Women affected by postpartum depressive symptoms are concerned about long-term health effects of their illness on their infants. Although postpartum depressive symptoms were associated with school-age asthma at ages 6 and 7, this association diminished later. Both home and school life stress should be considered in future studies on asthma development later in childhood.
authors: Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.|School of Public Health, University of Alberta, Edmonton, AB, Canada.|Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB, Canada.
authors: A L
authors: AL
authors: Kozyrskyj
authors: Faculty of Nursing & Cumming School of Medicine (Pediatrics & Psychiatry), University of Calgary, Calgary, AB, Canada.
authors: N L
authors: NL
authors: Letourneau
authors: Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.
authors: L J
authors: LJ
authors: Kang
authors: Department of Mathematics & Statistics, University of New Brunswick, Fredericton, NB, Canada.
authors: M
authors: M
authors: Salmani
mesh_terms: D000367:Age Factors; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology*; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D019052:Depression, Postpartum / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011159:Population Surveillance; D012306:Risk; D063189:Symptom Assessment
keywords: asthma; epidemiology; pediatrics