Risk Factors for Postpartum Depression: Family History of Psychiatric Illness
In the general population, about 15% of women will experience depression after the birth of a child. Given the downstream effects of postpartum depression (PPD) on the child’s health and well-being, it is essential that we be able to identify women at high risk for experiencing PPD. The identification of risk factors before delivery — or even before pregnancy — would allow us to monitor high risk women more closely and may also afford the opportunity to initiate preventative interventions which mitigate risk for illness.
A systematic review and meta-analysis from Zacher Kjeldsen and colleagues examined the association between family history of psychiatric illness and risk for postpartum depression. In their final analysis, a total of 26 studies were included, containing information on 100,877 women. The meta-analysis showed a twofold increased odds ratio (OR) of developing PPD when mothers had a family history of psychiatric illness (OR, 2.08; 95% CI, 1.67-2.59).
The meta-analysis from the current study indicates an almost twofold increase in risk of PPD in mothers with a family history of psychiatric disorders compared with mothers without family history. In other words, women with a family history of psychiatric illness will have a 30% risk of experiencing PPD. While this is a useful piece of information, this is most likely not a surprise to most. We know that having a family history of psychiatric illness increases one’s risk for depression, and having a history of depression increases risk for PPD. (However, some studies have not shown an association between family history of psychiatric illness and PPD.)
The current study did not look at specific psychiatric disorders. In another study analyzing data from the Danish medical register, researchers observed that if a woman had a first-degree relative (mother, father, brother, sister, or child) with a history of any psychiatric disorder, her risk of having an episode of postpartum psychiatric illness was about 1.5-fold higher than in women with no family history. However, if the woman had a first-degree relative with a history of bipolar disorder, her risk of having an episode of postpartum psychiatric illness increased nearly threefold. (In contrast to the study from Zacher Kjeldsen and colleagues, the Danish study looked at risk only in women with no personal history of psychiatric illness prior to pregnancy.)
Both studies remind us to ask about family history on both sides of the family. While having a mother or sister who has experienced postpartum psychiatric illness may increase a woman’s risk of PPD, having a brother or father with any type of psychiatric illness also confers significant risk.
What we do not yet know is how various risk factors — such as depressive symptoms during pregnancy or discontinuation of medications — interact with each other, nor do we know how protective factors (e.g., social supports) may modulate risk. Our ultimate goal would be to generate some sort of PPD risk calculator so that we could evaluate each woman and give a more personalized estimate of risk for perinatal psychiatric illness and to select appropriate preventative interventions. This is maybe where big data can help us.
Ruta Nonacs, MD PhD
Zacher Kjeldsen MM, Bricca A, Liu X, Frokjaer VG, Madsen KB, Munk-Olsen T. Family History of Psychiatric Disorders as a Risk Factor for Maternal Postpartum Depression: A Systematic Review and Meta-analysis. JAMA Psychiatry. 2022 Aug 17.