Studies have shown that a mother's history of childhood maltreatment is associated with her child's experience of internalising and externalising difficulties.

To characterise the mediating pathways that underpin this association.

Data on a mother's history of childhood maltreatment, depression during pregnancy, postnatal depression, maladaptive parenting practices and her child's experience of maltreatment and internalising and externalising difficulties were analysed in an Avon Longitudinal Study of Parents and Children (ALSPAC) sample of 9397 mother–child dyads followed prospectively from pregnancy to age 13.

Maternal history of childhood maltreatment was significantly associated with offspring internalising and externalising difficulties. Maternal antenatal depression, postnatal depression and offspring child maltreatment were observed to significantly mediate this association independently.

Psychological and psychosocial interventions focused around treating maternal depression, particularly during pregnancy, and safeguarding against adverse childhood experiences could be offered to mothers with traumatic childhood histories to help protect against psychopathology in the next generation.

Studies have shown that maternal depression during pregnancy predicts offspring depression in adolescence. Child maltreatment is also a risk factor for depression.

To investigate (a) whether there is an association between offspring exposure to maternal depression in pregnancy and depression in early adulthood, and (b) whether offspring child maltreatment mediates this association.

Prospectively collected data on maternal clinical depression in pregnancy, offspring child maltreatment and offspring adulthood (18–25 years) DSM-IV depression were analysed in 103 mother–offspring dyads of the South London Child Development Study.

Adult offspring exposed to maternal depression in pregnancy were 3.4 times more likely to have a DSM-IV depressive disorder, and 2.4 times more likely to have experienced child maltreatment, compared with non-exposed offspring. Path analysis revealed that offspring experience of child maltreatment mediated the association between exposure to maternal depression in pregnancy and depression in adulthood.

Maternal depression in pregnancy is a key vulnerability factor for offspring depression in early adulthood.