Acute Postpartum Mental Illness Linked To Later Bipolar Diagnosis
Women suffering from postpartum depression shortly after giving birth are more likely to be diagnosed with bipolar disorder later in life, according to a Danish study published Monday in the Archives of General Psychiatry.
The study is the first to draw the connection between the two conditions.
The researchers said it was not clear whether some postpartum depression or schizophrenia-like episodes were actually misdiagnosed bipolar disorder, or if more women with those initial diagnoses went on to develop bipolar disorder over time.
“We’re looking at severe psychiatric episodes,” said study author Trine Munk-Olsen at Aarhus University in an interview with Reuters.
Although “postpartum blues” are fairly common, severe depression and other acute psychiatric conditions requiring inpatient or outpatient care occur in just one in 1,000 new mothers, she added.
“The severe episodes are rare, but they are serious episodes and of course they should be taken seriously. You want these women to get help, no doubt,” she said.
Bipolar disorder is characterized by alternating swings between severe depression and energetic feelings of excitement and happiness. The condition, which can usually be treated with medications and talk therapy, typically manifests in early adulthood, with six percent of the U.S. population having the disorder at some point in life, according to estimates by the National Institute of Mental Health.
Previous studies have suggested giving birth may act as a trigger for initial episodes of bipolar disorder, although few women are actually diagnosed as bipolar in the weeks after having a baby, Munk-Olsen said.
The scientists hypothesized that a severe psychiatric episode shortly after giving birth might be a signal of underlying bipolar disorder. They tracked women in Denmark for 15 years after their first psychiatric episode to identify whether the timing of that incident — shortly after childbirth or not — predicted a diagnosis of bipolar diagnosis later in life.
Using Danish registries, they identified 120,000 women treated in an inpatient hospital or outpatient clinic for their first incidence of severe depression or another psychiatric condition beginning in 1970. Of those, 2,900 had episodes within a year of giving birth to their first child.
The researchers excluded women with an initial diagnosis of bipolar disorder, since they were interested in women with other psychoses that later became bipolar.
Over the next 15 years, nearly 3,100 of all women initially given a different diagnosis were ultimately diagnosed with bipolar disorder. Of the women who had their initial psychiatric episode within one month of giving birth, 14 percent were ultimately diagnosed as bipolar. This compares with just four to five percent of women who were first treated in the rest of the year after giving birth, or at any other time.
“It is likely that some of the women were misdiagnosed — we cannot rule that out — but it is likely that some of the women develop bipolar over time,” Munk-Olsen said.
The results represent a four-fold increase in the likelihood that a severe psychiatric episode in the month after giving birth, versus one that happens at some other time, would ultimately lead to a bipolar diagnosis.
Among women with early postpartum episodes, those admitted for inpatient psychiatric treatment were also twice as likely as those treated as outpatients to later be diagnosed as bipolar.
However, the findings do not prove that postpartum depression, or giving birth itself, causes bipolar disorder, and the researchers did not examine whether the less severe, more common postpartum blues are linked to bipolar symptoms.
Nevertheless, severe psychiatric symptoms that first show up soon after a woman gives birth should be included in the list of features that could increase the risk of bipolar disorder, the researchers said.
Doctors should “think about when women have their onset, and you might have an indication that there is an underlying bipolar disorder. We want these women to be diagnosed correctly, in order to help them in the best way,” Munk-Olsen said.
The study was published online December 5 in the Archives of General Psychiatry.
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