BackgroundPrenatal and postnatal depressive symptoms are common in expectant and new mothers and fathers. This study examined the association between four patterns of probable perinatal depression (mother depressed, father depressed, both depressed, neither depressed) in co-parenting mothers and fathers and their children’s internalizing and externalizing behaviours at 24 and 36 months of age. The influence of sociodemographic, risk and protective factors was also examined.MethodsDepressive symptoms were measured during pregnancy and at 3 months postpartum and children’s behaviour was assessed at 24 and 36 months of age. Families (n = 634) provided data on their children’s internalizing (i.e. emotionally reactive, anxious/depressed, somatic complaints, withdrawn and total) and externalizing (i.e. attention problems, aggression and total) behaviour. Marginal models were employed to determine the relationship between children’s behaviour over the two time points and the four patterns of probable parental depression. Sociodemographic variables as well as risk (stress) and protective (social support) factors were included in these models.ResultsIn the perinatal period 19.40% (n = 123) of mothers scored as probably depressed and 10.57% (n = 67) of fathers. In 6.31% (n = 40) of the participating families, both parents scored as probably depressed and in 63.72% (n = 404) neither parent scored as depressed. For children’s emotionally reactive, withdrawn and total internalizing behaviours, both mothers’ probable depression and mothers and fathers’ co-occurring probable depression predicted higher scores, while for children’s aggressive behaviour, attention problems, and total externalizing behaviours, only mothers’ probable depression predicted higher scores, controlling for sociodemographic, risk and protective factors.ConclusionsWhile probable perinatal depression in mothers predicted 2 and 3 year-old children’s behavioural problems, co-occurrence of depression in mothers and fathers had an increased association with internalizing behavioural problems, after considering sociodemographic, risk and protective factors. Health care providers are encouraged to consider the whole family in preventing and treating perinatal depression.