Is postpartum depression a distinct disorder?

The nosology of postpartum depression (PPD) is controversial. We review the evidence and arguments for and against the recognition of PPD as a distinct disorder and discuss the etiopathogenic and diagnostic validity of PPD as a distinct disorder, including its utility and indications for further research. Although multiple epidemiological and clinical studies have found that depression is more common following childbirth than at other times in a woman’s life, there is conflicting evidence for the validity of PPD as a distinct disorder. PPD is likely to be a complex phenotype, encompassing several disorders with different disease pathways. It is plausible that for a sub-group of vulnerable women, childbirth triggers episodes of depression. However, even within this group, the mechanisms underpinning the mood disturbances are likely complex and heterogeneous. The distinction between depression occurring in the perinatal period and depression at other times is important for both research and clinical practice. Research should differentiate between episodes that begin during pregnancy and postpartum, as the pathogenetic factors involved may differ and require specialized treatment