Having an autoimmune disease could increase your risk of PPD by 30%, study finds

Women who have an autoimmune disease are more likely to experience depression during pregnancy and after childbirth, according to a new study. But it doesn’t stop there: Those with a history of perinatal or postpartum depression are at higher risk of developing autoimmune disease, and the link is strongest specifically for multiple sclerosis (MS), the researchers found.

The study was published in the journal Molecular Psychiatry.

Investigators evaluated data from the Swedish Medical Birth Register, including all women who had given birth in Sweden between 2001 and 2013. There were approximately 815,000 women and 1.3 million pregnancies. During pregnancy or within a year of delivery, 55,299 women had been diagnosed with postpartum depression.

The researchers then looked at the incidence of 41 autoimmune diseases with and without perinatal or postpartum depression. The team also included data on sisters of the women affected.

Perinatal and postpartum depression tied to autoimmune diseases

The scientists discovered a bidirectional association between perinatal depression and various autoimmune diseases, indicating that the relationship is mutual. This means that having one of these conditions does not necessarily precede the other; instead, either perinatal depression can increase the risk of developing an autoimmune disease, or having an autoimmune disease can increase the risk of experiencing perinatal depression.

In fact, women with an autoimmune disease were 30% more likely to experience perinatal depression. On the flip side, women with perinatal depression were 30% more likely to develop a subsequent autoimmune disease. The risk was strongest for multiple sclerosis—the risk was double in both directions. The link between autoimmune disease and postpartum depression was also strongest in women who didn’t previously have a mental health diagnosis.

Autoimmune diseases occur when the immune system backfires and attacks cells, tissues and organs instead of protecting them. Common autoimmune diseases include rheumatoid arthritis, celiac disease, multiple sclerosis, lupus and type 1 diabetes.

Correlation but not causation

The study detected the link (correlation), but that doesn’t mean the researchers know whether having an autoimmune disease can cause postpartum or perinatal depression or vice versa (causation). More research is needed to uncover the unique role the immune system plays in perinatal depression. 

“Our study suggests that there’s an immunological mechanism behind perinatal depression and that autoimmune diseases should be seen as a risk factor for this kind of depression,” Emma Bränn, researcher at the Institute of Environmental Medicine at Karolinska Institutet, says in a statement. She emphasized that the study only found a link, but not cause and effect. 

Next up, the team wants to assess the long-term effects of depression during pregnancy and in the first year following childbirth.

“Depression during this sensitive period can have serious consequences for both the mother and the baby,” Bränn says. “We hope that our results will help decision-makers to steer funding towards maternal healthcare so that more women can get help and support in time.”