Perinatal Depression and Risk of Mortality: Nationwide, Register-Based Study in Sweden

( BMJ. 2024;384:e075462. doi: 10.1136/bmj-2023-075462) Perinatal depression (PD), which occurs either during pregnancy or after delivery, is diagnosed with the Diagnostic and Statistical Manual of mental disorders (DSMMD). Although PD is associated with decreased maternal well-being and an increased risk of suicide, the impact on maternal mortality is not clearly understood. The risk of death following a diagnosis of PD is specifically explored in this matched cohort Swedish study. To understand whether there are familial risk factors, including genetics and shared childhood experiences, in PD, the study design includes sibling comparison. Data for the study was sourced from the Swedish health registers, including the medical birth register, the national patient register, the national drug register, the multigenerational register, and the causes of death register. Pregnancies from 2001 to 2017 were examined, with exclusions including: multiple pregnancies, pregnancies after PD, and missing age. After exclusions, 1,029,215 women were considered part of the study base, while 86,551 of these women had received their first diagnosis of PD and received treatment either with antidepressants or other care (before the first year postpartum). The women diagnosed with PD were followed based on whether they were diagnosed with antepartum or postpartum depression. Ten women from the study base without a PD diagnosis were included for each woman (index) diagnosed with PD. Specifically, these 865,510 women, which make up the reference group for the study, were chosen based on their similar age and similar delivery date with the index women. In total, the reference group and the index women make up the population cohort. In addition, the sibling cohort was selected, with all pregnant women who gave birth during the study years (2001 to 2017) and had at least 1 full sister included.