Babies may benefit from moms’ lasting melancholy

A double dose of mom’s depression may do a baby good.

Infants generally thrive physically and mentally if their mothers’ emotional condition, whether healthy or depressed, remains stable before and after birth, say psychologist Curt Sandman of the University of California, Irvine, and his colleagues. Kids whose mothers stayed depressed from the fourth month of pregnancy on displayed first-year mental and physical development comparable to that of youngsters whose mothers stayed emotionally healthy for the same stretch, Sandman’s team will report in Psychological Science.

In contrast, babies’ first-year physical and mental development lagged if their mothers’ emotional state during pregnancy changed after giving birth. That pattern held whether depression during pregnancy resolved after giving birth or depression first appeared after delivering a child.

“A human fetus that prepares for inadequate care after birth based on biological messages from a depressed mother will have a survival advantage,” Sandman says. A fetus that gets thrown a caretaking curve upon leaving the womb — whether biologically primed to expect sufficient or deficient treatment — tends to struggle developmentally, at least for the first year, he suggests.

Related investigations have found that people whose mothers nearly starved during pregnancy eventually developed higher rates of diabetes and other metabolic disorders if they received enough food after birth, but not if they too got inadequate nutrition. Until now, no one has reported a health advantage for babies exposed to maternal depression before and after birth.

University of California, Davis, psychologist Jay Belsky calls the new findings “surprising, if not astonishing.” He awaits confirmation of Sandman’s results by other researchers before concluding that babies benefit from a womb with a view of upcoming hardships.

Babies may respond to maternal depression differently based on their genetic makeup, Belsky suggests (SN Online: 4/6/11). In the March 15 Biological Psychiatry, he and his colleagues reported that infants carrying two copies of a particular serotonin transporter gene variant frequently became scared and agitated if their mothers experienced intense anxiety during pregnancy.

For the new study, Sandman’s team studied 221 women at five points during their pregnancies. The women and their babies were then assessed at three-month intervals for one year. Experimenters used play tasks to measure infants’ physical and mental development.

Kids whose mothers displayed consistent emotional health or depression scored higher than those exposed to inconsistent maternal moods on physical tasks at age three months, on both physical and mental tasks at age six months, and on mental tasks at age 1. The researchers plan to see if that mental advantage lasts longer or if maternal depression eventually undermines mental development.

Results so far underscore the need to rapidly treat pregnant women’s depression so that their children experience positive maternal health before and after birth, Sandman suggests. But antidepressant medication presents health risks for fetuses, and the new findings indicate that women who attain emotional health shortly after giving birth create conditions that slow their babies’ development.

“What is best for the mother may not be best for the fetus or infant,” Sandman says.