A population-based study shows that the children of women who experience depression during pregnancy are 1.5 times more likely to be depressed themselves as teens.

Depression is believed to have a genetic link, but a new study suggests a mother’s mental health while pregnant can affect her child even more directly.

Research published in the journal JAMA Psychiatry suggests that women who experience depression during pregnancy give their children an increased risk of depression as adults.

Rebecca M. Pearson, Ph.D., of the University of Bristol in the U.K., and her colleagues used data from more than 4,500 patients and their children in a community-based study. The researchers concluded that children born to depressed mothers were, on average, 1.5 times more likely to be depressed at 18 years old.

While shared genetic risk is one potential explanation, Pearson said the physiological consequences of depression experienced by the mother can pass through the placenta and may influence the fetus’ brain development.

“At an individual level the risks are very small. Having said this, these differences are meaningful at a population level,” Pearson told Healthline.

Prenatal depression affects about 10 to 15 percent of women and is as common as postnatal depression, more commonly called postpartum depression.

While pregnant women often feel surges of emotion due to hormonal changes, more serious mood changes may be related to depression. These symptoms include feelings of sadness, hopelessness, or being overwhelmed, excessive crying, having no energy, losing interest in once pleasurable activities, or withdrawing from friends.

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Researchers say the monitoring and protections that are in place for postpartum depression are not there for women with prenatal depression.

“We really don’t want to scare pregnant women or make them feel guilty,” Pearson said. “Nonetheless, the message is to prioritize your own mental state and seek help early in pregnancy if you are feeling low, both for your own sake and for your baby.”

Researchers say their findings have important implications for the nature and timing of interventions to prevent depression in children of depressed mothers.

“In particular, the findings suggest that treating depression in pregnancy, irrespective of background, may be most effective,” the study concludes.

Treatments like cognitive behavioral therapy—a kind of talk therapy—have been shown to help women with depression without the risk of side effects that comes with some psychoactive medications.

“Health professionals should be aware and ready to support women,” Pearson said. “Depression during pregnancy is important in its own right and not just because it may continue after birth.”