2002 International International Biennial Scientific Meeting

THE VALUE OF TWIN STUDIES IN UNDERSTANDING POSTNATAL DEPRESSION

Susan A Treloar

Queensland Institute of Medical Research, Brisbane

sueT@qimr.edu.au

Studying genetically identical and non-identical twin pairs and their offspring offers a well-documented means of testing key hypotheses about genetic and environmental influences on human behaviour, health and disease. Parents of multiple versus singleton births have been studied and reported. However, this paper will offer insights into a more powerful focus for research involving twins and families. The relevance of the twin and family design may not be immediately apparent when it comes to studying problems such as predisposition to postnatal depression. I will describe our own study of postnatal depressive symptoms and relationship with liability to depression in a twin sample recruited through the Australian Twin Registry. We studied a large sample of female twin pairs who had both given birth at least once. Such a design also has the potential to investigate genetic and environmental influences on mother-infant interaction. Even more interesting are the opportunities afforded by studying twin pairs discordant for particular behaviours (e.g. eating disorders) to identify associated precursors, such as relevant parental bonding factors. Twin pairs and their offspring have also provided data for other studies concerning influences on parenting characteristics, elicitation of parenting by children, and the effects of parenting on children. Some studies on parenting and attachment will also be reviewed as examples of the immense possibilities of twin and family research methodology.