Some of the evidence that parental depression has adverse effects on children comes from studies where one or sometimes both parents have bipolar disorders, which is a vastly different picture from a more typical postnatal depression, treated, or as often not treated, in the community. If both partners are depressed they are not available to offer support to each other, and the risk to children increases, with neither parent available to compensate for the difficulties of the other. Poor interaction and maternal depression are not coterminous although they do overlap to a degree. Treatment for postnatal depression is effective, but the needs of the child require special attention and only in rare cases are infant mental health services developed. Effective intervention for parents and children requires the co-ordination of primary and secondary care services across the age range, in combinations that may lie outside the usual multidisciplinary boundaries.