Depressed mums may have shorter children — Study

October 4, 2012 by Maureen Azuh

A recent study indicates that women’s mood after childbirth affects children’s growth, writes MAUREEN AZUH

Depression is hardly associated with a positive effect on the human body. In a recent study, however, researchers have further found that mothers’ mood rub off on the children both mentally and physically.

In the study published September 10 in the journal Pediatrics, researchers found that children whose mothers had depressive symptoms during the first nine months after birth are more likely to be shorter that their peers.

The researchers studied data on 6,500 kids who were participating in the U.S. Early Childhood Longitudinal Study Birth Cohort from 2001 to 2007, and analysed the heights of children at three different periods: nine months, at age four and again when they were five or six, approximately kindergarten age.

Other researches had found that a mother’s postpartum depressive symptoms can influence growth during the first two years of a child’s life, but the new study finds that the effects may persist in even older children.

The study found that at the age of four, children with mothers who had reported mild or moderate depression when they were infants were 40 per cent more likely to be in the 10th percentile of height or shorter, compared with other kids their age whose mothers did not report early depression symptoms. By age five, kids of depressed mums were 48 per cent more likely to be at or below the 10th percentile of height.

However, the study does not prove that mum’s depression causes a child’s short stature, but that the two are associated. The authors could also not confirm the underlying mechanism linking the two factors. But they have some theories: maternal depression can lead to increased stress in children, for example, and chronically high levels of the stress hormone cortisol have been associated with lower levels of growth hormones in kids. Depressed mothers may also have poor feeding practices like spending less time breast feeding which may in turn affect growth.

Lead researcher and assistant professor at Johns Hopkins Bloomberg School of Public Health, Pamela Surkan, says depression might also get in the way of nurturing.

“We think that mothers who are depressed or blue might have a hard time following through with caregiving tasks,” she says. “We know that children of depressed mothers often suffer from poor attachment and the depression seems to have effects on other developmental outcomes. It makes sense that mothers who have depressive symptoms might have reduced ability to take care of infants that they might not always pick up cues from their kids.”

Another study published in April issue of Child Development also found that depressed mothers are more likely to wake up their babies at night than those who are not depressed – unlike the norm that babies should not be disturbed while they sleep.

Pennsylvania State researchers found that mothers with high depressive symptom levels are more likely to excessively worry about their infants at night than mothers with low symptom levels, and such mothers were more likely to seek out their babies at night and spend more time with their infants than mothers with low symptom levels.

Associate director of the Social Science Research Institute and professor of human development, psychology and pediatrics, Douglas Teti, says one interesting thing about the finding is that when depressed mothers sought out their infants at night, their infants did not appear to be in need of parental help. They were either sound asleep or perhaps awake, but not distressed.”

Depression in mothers does only affect infants and toddlers but in most cases have a long-term effect. In a 2010 report, researchers found that a mother’s depression in pregnancy is tied to antisocial behaviour in teenagers.

The study, also published in Child Development, found that children from urban areas whose mothers suffer from depression during pregnancy are more likely than others to show antisocial behaviour, including violent behaviour, later in life. It also found that women who are aggressive and disruptive in their own teenage years are more likely to become depressed in pregnancy, so that the mothers’ history predicts their own children’s antisocial behaviour.

The study conducted by researchers at Cardiff University, King’s College London, and the University of Bristol considered the role of mothers’ depression during pregnancy by looking at 120 British youth from inner-city areas.

Professor of psychology, Cardiff University in Wales, Dale Hay, who was involved in the research, says much attention has been given to the effects of postnatal depression on young infants but depression during pregnancy may also affect the unborn child.

The teens’ mothers were interviewed while they were pregnant, after they gave birth, and when their children were four, 11, and 16 years old. According to the study, mothers who became depressed when pregnant were four times as likely to have children who were violent at 16. The result was true for both boys and girls.

The mothers’ depression in turn, was predicted by their own aggressive and disruptive behaviour as teenagers.

Hay says, “Although it’s not yet clear exactly how depression in pregnancy might set infants on a pathway toward increased antisocial behavior, our findings suggest that women with a history of conduct problems who become depressed in pregnancy may be in special need of support.”