This paper identifies how developmental approaches can contribute to our understanding of depression. First, our understanding of the role of childhood experience, and its interaction with genetic variation, is considered. The paper then examines how the consequences of different kinds of maltreatment in the course of development point to contrasting mechanisms linking adversity to depression. This strengthens our understanding of the heterogeneity which is encountered in depression. Developmental research strongly supports the view that depression is a complex disorder both in terms of its character and origins, and that it may be arrived at along multiple pathways.