Family History not a Major Risk Factor for Postpartum Depression

Marie-Louise H. Rasmussen

There are a number of reasons why postpartum depression (PPD) can manifest in an individual and while family history is a factor, new research does not support it asmajor factor.

A team, led by Marie-Louise H. Rasmussen, Department of Epidemiology Research, Statens Serum Institut, examined whether or not familial aggregation is a major risk factor for postpartum depression and whether first-degree blood relatives through third-degree blood relatives with and without a history of psychiatric disorders is a factor.

Family Connection

Psychiatric disorders often have a strong familial aggregation. However, it is not yet known whether PPD without prior psychiatric history aggregates in families.

In the study, the investigators used data from Danish national registers to build a cohort with information on 848,544 singleton deliveries between 1996-2017. The investigators defined women with an episode of PPD as individuals having used antidepressant medication and/or had a hospital contact for depression within 6 months following delivery.

In addition, participants with a history of psychiatric illness prior to delivery were excluded from the study.

The team estimated the relative risk (RR) of PPD and compared women with female relatives with and without PPD history.

The Risk

The investigators found women with a history of PPD in blood relatives ultimately had a higher risk of developing the disease themselves (RR, 1.64; 95% CI, 1.16-2.34).

In addition, those with a first-degree female relative with PPD history were more than 2.5 times likelier to have PPD (RR, 2.65; 95% CI, 1.79-3.91).

However, the same is not true for those who have a second or third-degree female relative (RR, 0.58; 95% CI, 0.26-1.28). The same was true for those with a female non-blood relative with PPD history (RR, 1.09; 95% CI, 0.83-1.44).

“PPD aggregates in families with no other psychiatric history, but the findings do not support a strong genetic trait as a major cause,” the authors wrote. “Other possible mechanisms are shared environment and/or health-seeking behavior in close relationships.”

PPD and COVID-19

As the COVID-19 pandemic continued, physician visits for individuals with postpartum mental illnesses were significantly higher than what was expected based on prepandemic data.

A team, led by Simone N. Vigod, MD, MSc, Women’s College Research Institute, compared physician visit rates for postpartum mental illness in Ontario during the pandemic with rates that were expected based on prepandemic patterns.

It is not yet known whether or not the clinical burden of postpartum mental illness has increased during the course of the COVID-19 pandemic, but there have been reports throughout the pandemic on concerns about postpartum infections and difficulty accessing the extended postpartum social support networks and key community programs such as home visits from public health nurses, breastfeeding clinics, and support groups.

The visit rate was 43.6 per 1000 individuals in March 2020, with a rate different of 3.11 per 1000 (95% CI, 1.25-4.89) and an incidence rate ratio (IRR) of 1.08 (95% CI, 1.03-1.13) compared to the expected rate.

For April, the rate difference was 10.9 per 1000 patients (95% CI, 9.14-12.6), while the IRR was 1.30 (95% CI, 1.24-1.36).

The higher levels were generally sustained throughout the duration of the pandemic study period.

The study, “Familial risk of postpartum depression,” was published online in Acta Psychiatrica Scandinavica.