Interpreting the effects of mothers' postnatal depression on children's intelligence: a critique and re-analysis.

It is possible that reported links between postnatal depression and children's cognitive deficits can be completely explained by vulnerability factors in the child such as male gender and pre- and perinatal insults as well as known risk factors in the social environment. This hypothesis was evaluated, using prospective longitudinal data that had previously been obtained from a community sample of primiparous North London women, followed from early pregnancy until the children were 4 years old. Re-analysis of those data provided support for the original finding of an association between postnatal depression and impaired cognitive abilities in the children. There were, however, some important modifications: Low birth-weight infants and the infants of less educated mothers were most at risk. Perceptual and performance abilities were most affected.