a1 Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
a2 Centre for Women's Mental Health, Manchester Academic Health Sciences, University of Manchester, UK
a3 Anu Research Centre, Department of Obstetrics and Gynaecology, University College Cork, Ireland
a4 Department of Public Health Sciences, Division of Public Health Epidemiology, Karolinska Institutet, Stockholm, Sweden
a5 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
Background Preconception, prenatal and postnatal maternal stress is associated with increased offspring psychopathology, but findings are inconsistent and need replication. We estimated associations between maternal bereavement stress and offspring autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, suicide attempt and completed suicide.
Method Using Swedish registers, we conducted the largest population-based study to date examining associations between stress exposure in 738 144 offspring born 1992–2000 for childhood outcomes and 2 155 221 offspring born 1973–1997 for adult outcomes with follow-up to 2009. Maternal stress was defined as death of a first-degree relative during (a) the 6 months before conception, (b) pregnancy or (c) the first two postnatal years. Cox proportional survival analyses were used to obtain hazard ratios (HRs) in unadjusted and adjusted analyses.
Results Marginal increased risk of bipolar disorder and schizophrenia following preconception bereavement stress was not significant. Third-trimester prenatal stress increased the risk of ASD [adjusted HR (aHR) 1.58, 95% confidence interval (CI) 1.15–2.17] and ADHD (aHR 1.31, 95% CI 1.04–1.66). First postnatal year stress increased the risk of offspring suicide attempt (aHR 1.13, 95% CI 1.02–1.25) and completed suicide (aHR 1.51, 95% CI 1.08–2.11). Bereavement stress during the second postnatal year increased the risk of ASD (aHR 1.30, 95% CI 1.09–1.55).
Conclusions Further research is needed regarding associations between preconception stress and psychopathological outcomes. Prenatal bereavement stress increases the risk of offspring ASD and ADHD. Postnatal bereavement stress moderately increases the risk of offspring suicide attempt, completed suicide and ASD. Smaller previous studies may have overestimated associations between early stress and psychopathological outcomes.
(Received November 28 2012)
(Revised March 07 2013)
(Accepted March 09 2013)
(Online publication April 17 2013)