Risk Factors for Postpartum Depression
Postpartum, or postnatal, depression affects a significant proportion of women after they have had a baby. It usually develops in the first four to six weeks after childbirth, although in some cases it may not develop until several months later.
Symptoms of postpartum depression include low mood, fatigue, anxiety, irritability, feeling unable to cope and difficulty sleeping, but it is often undetected and commonly under-diagnosed. It is important for postpartum depression to be recognized as soon as possible so treatment can begin.
Studies report that postpartum depression affects somewhere between one in 20 and one in four mothers. It is distinct from the so-called “baby blues,” which is a transitory state of tearfulness suffered by about half of postnatal women within about three to four days of birth. Baby blues tends to last from a few hours to several days, and there is no established link to a higher likelihood of postpartum depression.
Many people believe that postpartum depression (PPD) is caused by changes in hormone levels during and shortly after pregnancy, but this idea is disputed by some experts. Other possible triggers include inability to breastfeed (if it was hoped for), a history of depression, abuse, or mental illness, smoking or alcohol use, fears over child care, anxiety before or during pregnancy, background stress, a poor marital relationship, a lack of financial resources, the infant’s temperament or health problems such as colic, and especially lack of social support.
Genes may also play a role in predisposing women to postpartum depression. In a recent study, researchers investigated whether susceptibility can be explained by certain genetic variants. Elizabeth Corwin, PhD, of the University of Colorado-Denver, looked at three categories of genes known to code for proteins associated with depression in the general population.
But they found that “the contribution of genetic polymorphisms to the development of postpartum depression” remains unclear. “Much more research is required to understand the heritability of postpartum depression,” they write.
Clearer results have been found in studies of brain chemistry following birth. A team from the University of Toronto, Canada, explains that estrogen levels drop 100- to 1000-fold in the days following birth. Changes in estrogen levels are associated with levels of an enzyme called monoamine oxidase A (MAO-A).
The team measured MAO-A in the brain among 15 women at four to six days after birth. They saw that, “MAO-A total distribution volume was significantly elevated (by a mean of 43 percent) throughout all analyzed brain regions” compared with 15 comparison women.