Perinatal Depression: Decades of Elevated Mortality Risk

Summary: A new study highlights the long-term mortality risks associated with perinatal depression. Analyzing data from over 86,500 women, the research found that those experiencing depression during or shortly after pregnancy are at a higher risk of death from natural and unnatural causes for up to 18 years post-diagnosis.

This risk is particularly pronounced in the first month following diagnosis but remains significant long-term. The study emphasizes the need for continuous, effective psychiatric care and widespread screening for perinatal depression.

Key Facts:

1. Women with perinatal depression have a doubled risk of mortality compared to those without, with the risk peaking in the month after diagnosis and persisting for up to 18 years.
2. The study used data from the Swedish Medical Birth Register, comparing over 86,500 affected women with 865,500 controls, making it one of the most comprehensive studies in this field.
3. Perinatal depression affects 10-20% of all pregnant women and is primarily treated with cognitive behavioral therapy and, if necessary, medication.

Source: Karolinska Institute

Women who suffer depression during or after pregnancy have a higher risk of death by both natural and unnatural causes, a new study of childbirth in Sweden published in The BMJ reports. The increased risk peaks in the month after diagnosis but remains elevated for as long as 18 years afterwards.

Women who develop perinatal depression, which is to say depression during pregnancy or shortly after childbirth, are generally twice as likely to die of natural or, as in most cases, unnatural causes.

They are six times more likely to commit than women without this form of depression. The increase in risk peaks in the 30 days following diagnosis but remains elevated for up to 18 years later.

These are the results of a large cohort study that used data from the Swedish Medical Birth Register, which effectively contains all births in Sweden since 1973.

Basing their study on women who had live births between 2001 and 2018, the researchers compared over 86,500 women diagnosed with perinatal depression, during pregnancy or up to one year after childbirth, with over 865,500 matched controls of the same age who had given birth the same year.

“This is a cohort study, and although it can’t prove any causality, it’s the largest and most comprehensive study in its field,” says Qing Shen, affiliated researcher at the Institute of Environmental Medicine, Karolinska Institutet and one of the principal authors of the study. “I believe that our study clearly shows that these women have an elevated mortality risk and that this is an extremely important issue.”

The risk was highest for the women diagnosed with postpartum depression (depression after childbirth), corroborating the findings of previous smaller studies. Women diagnosed with antepartum depression (depression during pregnancy) have not been studied as much, so the knowledge base there is smaller. Dr Shen and her colleagues can now show that women with antepartum depression also have an elevated mortality risk, albeit not as high.

On comparing the mortality risk among women with perinatal depression who had had psychiatric problems even before pregnancy with women who had not had such issues, the researchers found that it was the same for both groups.

“Our recommendation is therefore not to discontinue effective psychiatric treatment during pregnancy,” says Dr Shen.

The women who were diagnosed with perinatal depression tended to have been born in the Nordic region and have a shorter education history and lower incomes than women without such a diagnosis.

“One hypothesis is that these women seek help differently or were offered screening service postpartum not to the same extent, which means that their depression develops and is worse once it has been detected,” says last author Donghao Lu, assistant professor at the Institute of Environmental Medicine, Karolinska Institutet. “Our view is that these women are particularly vulnerable and should be the focus of future interventions.”

However, rather than introducing new measures, Dr Lu, argues that it is a matter of making better use of those already in place.

“Sweden already has many excellent tools, such as a postpartum questionnaire to screen the symptoms of postpartum depression,” says Donghao Lu. “We need to stress how important it is for all pregnant women are offered screening, both postpartum and antepartum, and provided necessary, evidence-based care and support.”

Funding: The study was financed by several bodies, including the Swedish Research Council for Health, Working Life and Welfare (Forte), the Swedish Research Council, Karolinska Institutet’s Strategic Research Area in Epidemiology and Biostatistics (SFOepi) and the Icelandic Research Fund.

Facts:

• Perinatal depression is fairly common and affects 10 – 20 percent of all pregnant women.
• Since depression extends over a rather sensitive time in life, it can have serious consequences.
• Previous studies have shown a link between postpartum depression and an increased risk of suicide, but otherwise, there were considerable gaps in our knowledge about the risks before this study.
• Six to eight weeks after childbirth, all women in Sweden are asked to complete a form called the Edinburgh Postnatal Depression Scale (EPDS), which is used to detect signs of depression.
• Perinatal depression is primarily treated with cognitive behavioral therapy (CBT) and other forms of talking therapy, possibly in combination with medication.

About this depression and mortality research news

Author: Qing Shen
Source: Karolinska Institute
Contact: Qing Shen – Karolinska Institute
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Perinatal depression and risk of mortality: nationwide, register based study in Sweden” by Qing Shen et al. BMJ

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Abstract

Perinatal depression and risk of mortality: nationwide, register based study in Sweden

Objective 

To determine whether women with perinatal depression are at an increased risk of death compared with women who did not develop the disorder, and compared with full sisters.

Design 

Nationwide, register based study.

Setting 

Swedish national registers, 1 January 2001 to 31 December 2018.

Participants 

86 551 women with a first ever diagnosis of perinatal depression ascertained through specialised care and use of antidepressants, and 865 510 women who did not have perinatal depression were identified and matched based on age and calendar year at delivery. To address familial confounding factors, comparisons were made between 270 586 full sisters (women with perinatal depression (n=24 473) and full sisters who did not have this disorder (n=246 113)), who gave at least one singleton birth during the study period.

Main outcome measures 

Primary outcome was death due to any cause. Secondary outcome was cause specific deaths (ie, unnatural and natural causes). Multivariable Cox regression was used to estimate hazard ratios of mortality comparing women with perinatal depression to unaffected women and sisters, taking into account several confounders. The temporal patterns of perinatal depression and differences between antepartum and postpartum onset of perinatal depression were also studied.

Results 

522 deaths (0.82 per 1000 person years) were reported among women with perinatal depression diagnosed at a median age of 31.0 years (interquartile range 27.0 to 35.0) over up to 18 years of follow-up. Compared with women who did not have perinatal depression, women with perinatal depression were associated with an increased risk of death (adjusted hazard ratio 2.11 (95% confidence interval 1.86 to 2.40)); similar associations were reported among women who had and did not have pre-existing psychiatric disorder.

Risk of death seemed to be increased for postpartum than for antepartum depression (hazard ratio 2.71 (95% confidence interval 2.26 to 3.26) v 1.62 (1.34 to 1.94)). A similar association was noted for perinatal depression in the sibling comparison (2.12 (1.16 to 3.88)). The association was most pronounced within the first year after perinatal depression but remained up to 18 years after start of follow up.

An increased risk was associated with both unnatural and natural causes of death among women with perinatal depression (4.28 (3.44 to 5.32) v (1.38 (1.16 to 1.64)), with the strongest association noted for suicide (6.34 (4.62 to 8.71)), although suicide was rare (0.23 per 1000 person years).

Conclusions 

Even when accounting for familial factors, women with clinically diagnosed perinatal depression were associated with an increased risk of death, particularly during the first year after diagnosis and because of suicide. Women who are affected, their families, and health professionals should be aware of these severe health hazards after perinatal depression.