Genes May Boost Woman's Risk of Postpartum Depression
Test found specific changes to two genes predicted problem with 85 percent accuracy
Another 32 women were depression-free during pregnancy, but 11 developed postpartum depression.
Based on research with mice, Kaminsky's team suspected that estrogen triggers so-called epigenetic changes in genes in the brain's hippocampus. With epigenetic changes, there is no defect in the underlying DNA, but a gene's activity is altered. The results of research conducted in mice, however, often are not able to be replicated in humans.
The researchers found that epigenetic changes in the TTC9B and HP1BP3 genes were predictive of a woman's risk of postpartum depression.
Yonkers said one theory has been that women who develop postpartum depression may respond differently to the big shifts in estrogen and other hormones that happen during pregnancy and after childbirth.
Kaminsky said the new findings give some insight into that hormonal response. But he said more research is needed to really understand what's going on.
The results also need to be confirmed in a larger, more diverse group of women, Kaminsky said. "The women in this study all had been previously diagnosed with depression or bipolar disorder," he said. "We really need to look at this in a general population of women too."
In general, experts suspect that many factors come together to cause postpartum depression, including a woman's particular circumstances, such as whether she has a good "support network," if she has other major stressors in her life or whether the pregnancy was planned or not.
So no blood test would tell the whole story.
Right now, doctors may diagnose postpartum depression either because a woman complains of symptoms, or through a screening questionnaire. Yonkers said experts differ on whether new mothers should be routinely screened; the American Academy of Pediatrics, for example, says pediatricians should screen moms for depression during newborn checkups.
Other groups, including the American College of Obstetricians and Gynecologists, do not advise routine screening, but say doctors and women should consider it.