Sex differences in foetal origins of child emotional symptoms: a test of evolutionary hypotheses in a large, general population cohort.

We replicated the finding from the WCHADS that prenatal depression modifies the association between postnatal depression and children's emotional problems in a sex-dependent fashion. In ALSPAC, the sex difference was explained mainly by a protective effect of low prenatal depression in boys, while in WCHADS, it arose from greater vulnerability of girls to postnatal depression following low prenatal depression. In the light of these findings, in evaluating and implementing early interventions, there is need to consider that risks associated with postnatal depression may vary depending on maternal mood during pregnancy and may differ between boys and girls.