INTRODUCTION: Substance use disorder (SUD) is associated with major socioeconomic consequences but its etiology is only partly known. The disease predisposition may be established early in life and prenatal stress may play a role. We aimed to examine whether prenatal maternal bereavement, as the indicator of prenatal stress, was associated with an increased risk of SUD in offspring. METHODS: This population-based cohort study included all children born in Denmark (N=1686416) and Sweden (N=2563659) from 1973 to 1997. The exposure was maternal bereavement by the death of a close relative 1 year before or during pregnancy. Children were followed from 10 years of age until their death, migration, onset of substance abuse, or December 31st, 2007. The main outcome is hospitalization due to substance use disorder (SUD). RESULTS: A total of 100363 children (2.45%) were born to mothers who had experienced bereavement 1 year before or during pregnancy. Overall, these exposed children had a similar risk of hospitalization due to SUD (IRR=1.02, 95% CI: 0.98-1.07), compared to unexposed children. Children born to mothers who lost a spouse during pregnancy had a two-fold risk (IRR=2.19, 95% CI: 1.74-2.76) and similar elevated risks were observed in children whose mothers lost a spouse during the first 10 years after child birth. CONCLUSIONS: Our data do not support a programming role of prenatal stress following maternal bereavement on SUD later in life. The increased risk in relation to spousal bereavement may mostly be explained by postpartum changes in familial environment.
INTRODUCTION: Substance use disorder (SUD) is associated with major socioeconomic consequences but its etiology is only partly known. The disease predisposition may be established early in life and prenatal stress may play a role. We aimed to examine whether prenatal maternal bereavement, as the indicator of prenatal stress, was associated with an increased risk of SUD in offspring. METHODS: This population-based cohort study included all children born in Denmark (N=1686416) and Sweden (N=2563659) from 1973 to 1997. The exposure was maternal bereavement by the death of a close relative 1 year before or during pregnancy. Children were followed from 10 years of age until their death, migration, onset of substance abuse, or December 31st, 2007. The main outcome is hospitalization due to substance use disorder (SUD). RESULTS: A total of 100363 children (2.45%) were born to mothers who had experienced bereavement 1 year before or during pregnancy. Overall, these exposed children had a similar risk of hospitalization due to SUD (IRR=1.02, 95% CI: 0.98-1.07), compared to unexposed children. Children born to mothers who lost a spouse during pregnancy had a two-fold risk (IRR=2.19, 95% CI: 1.74-2.76) and similar elevated risks were observed in children whose mothers lost a spouse during the first 10 years after child birth. CONCLUSIONS: Our data do not support a programming role of prenatal stress following maternal bereavement on SUD later in life. The increased risk in relation to spousal bereavement may mostly be explained by postpartum changes in familial environment.