Maternal Age at Child Birth, Birth Order, and Suicide at a Young Age: A Sibling Comparison
Open Access
- 10 March 2013
- journal article
- research article
- Published by Oxford University Press (OUP) in American Journal of Epidemiology
- Vol. 177 (7), 638-644
- https://doi.org/10.1093/aje/kwt014
Abstract
Previous studies have reported strong associations between birth order, maternal age, and suicide, but these results might have been confounded by socioeconomic and other factors. To control for such factors, we compared suicide risk between siblings and studied how maternal age at child birth and birth order influenced risk in a cohort study of 1,690,306 Norwegians born in 1967–1996 who were followed up until 2008. Using stratified Cox regression, we compared suicide risk within families with 2 or more children in which one died from suicide. Altogether, 3,005 suicides occurred over a mean follow-up period of 15 years; 2,458 of these suicides occurred among 6,741 siblings within families of 2 or more siblings. Among siblings, a higher position in the birth order was positively associated with risk; each increase in birth order was associated with a 46% (adjusted hazard ratio = 1.46, 95% confidence interval: 1.29, 1.66) higher risk of suicide. For each 10-year increase in maternal age at child birth, the offspring's suicide risk was reduced by 57% (adjusted hazard ratio = 0.43, 95% confidence interval: 0.30, 0.62). Our study suggests that confounding due to familial factors is not likely to explain the associations of birth order and maternal age at child birth with suicide risk.Keywords
This publication has 28 references indexed in Scilit:
- Perinatal and psychosocial circumstances associated with risk of attempted suicide, non-suicidal self-injury and psychiatric service use. A longitudinal study of young peopleBMC Public Health, 2011
- Fetal growth, early life circumstances, and risk of suicide in late adulthoodEuropean Journal of Epidemiology, 2011
- Commentary: Advent of sibling designsInternational Journal of Epidemiology, 2011
- Perinatal circumstances and risk of offspring suicideThe British Journal of Psychiatry, 2006
- Studying suicide from the life course perspective: Implications for preventionThe British Journal of Psychiatry, 2005
- Restricted fetal growth and adverse maternal psychosocial and socioeconomic conditions as risk factors for suicidal behaviour of offspring: a cohort studyThe Lancet, 2004
- The epidemiology of case fatality rates for suicide in the northeastAnnals of Emergency Medicine, 2004
- Resolving the debate over birth order, family size, and intelligence.American Psychologist, 2000
- Survival analyses in twin studies and matched pair experimentsBiometrika, 1974
- Birth Order, Family Size, and IntelligenceScience, 1973