Depression in pregnancy is much more common than previously thought, with approximately one in 12 pregnant women suffering from clinically significant levels of depression. Although previous research has documented a link between depression during pregnancy and depression in adolescent offspring, this is the first study to examine the association in adulthood.
Drawing on data from the longitudinal South London Child Development Study (SLCDS), the researchers analysed depression in pregnancy, offspring child maltreatment and offspring adulthood depression amongst 103 mothers and their children who were born in 1987.
Published today in the British Journal of Psychiatry, the study found that of 35 adult offspring exposed to maternal depression during pregnancy, 57 per cent met diagnostic criteria for depression, compared to 28 per cent of those not exposed to maternal depression during pregnancy.
Child maltreatment, including physical, sexual and emotional abuse and neglect, was measured at ages 11, 16 and 25 through interviews conducted with the offspring and the primary caregiver – in most cases the mother. Researchers found that childhood maltreatment was more common amongst the offspring of mothers who were depressed in pregnancy (49 per cent compared with 28 per cent).
Dr Dominic Plant from the IoPPN, King’s College London, said: ‘Our study is the first to demonstrate the impact of mothers’ depression during pregnancy on depression in their children as young adults, and importantly, we found childhood maltreatment to be a strong mediating factor.
‘However, it is crucial to acknowledge that mothers were not the main perpetrators of this abuse – rather, it was primarily at the hands of peers and other adults in the family network.’
Dr Susan Pawlby, also from the IoPPN and senior author of the study, said: ‘Interestingly, we did not find that exposure to mothers’ depression in the postnatal period contributes to offspring depression, which suggests that depression specifically during pregnancy represents a unique setting for the transmission of risk to the next generation.’
Professor Carmine Pariante, Head of the Academic Section of Perinatal Psychiatry at the IoPPN and co-author of the study, added: ‘This finding is in line with previous research into foetal development, which suggests that exposure to elevated levels of maternal stress hormones in the uterus can result in changes in brain development, particularly in regions related to stress reactivity.'
According to the researchers, child maltreatment such as that observed in the study may be explained primarily by changes to mothers’ caregiving behaviours and their ability to protect their child, a poor attachment relationship between mother and child, conflict between parents and changes to parenting practices.
Dr Plant concluded: ‘Taken together, our findings support the notion that exposure to maternal depression during pregnancy and exposure to child maltreatment are likely part of the same pathway to adulthood depression.
‘By intervening during pregnancy, rates of both child maltreatment and depressive disorders in the young adult population could potentially be reduced. All expectant women could be screened for depression and those identified offered prioritised access to psychological therapies – as indeed is currently recommended by the UK guidelines on perinatal mental health.
‘We also hope that these findings will inform the current debate on the use of antidepressants during pregnancy by highlighting the adverse consequences of not treating depression.’
Dr Hugh Perry, Chair of the Neurosciences and Mental Health board at the Medical Research Council (MRC), said: ‘This important study demonstrates that even events in utero can impact on mental health later in life. It adds further support to the evidence that maltreatment in childhood can have long-term consequences on mental health in adulthood. It is by no means straightforward to disentangle the cause and effect of negative experiences in childhood on lifelong mental health, but with continued research offering new insights we will be much better placed to do so.’