Maternal depression can negatively impact a child’s cognitive development at least until the age of 16, according to a new study published in the journal Child Development.
Researchers from the University of California (UC), San Diego School of Medicine evaluated approximately 900 healthy children and their mothers living in Santiago, Chile at five-year intervals from the child’s infancy through age 16.
The research team noted how affectionate and responsive the mothers were to their children at each age period and also how well the mothers were able to provide age-appropriate learning materials. Children were assessed on verbal cognitive skills using standardized IQ tests during each assessment. Mothers were evaluated for symptoms of depression.
“We found that mothers who were highly depressed didn’t invest emotionally or in providing learning materials to support their child, such as toys and books, as much as mothers who were not depressed. This, in turn, impacted the child’s IQ at ages 1, 5, 10 and 16,” said Patricia East, Ph.D., research scientist with the Department of Pediatrics at UC San Diego School of Medicine.
“The consistency and longevity of these results speak to the enduring effect that depression has on a mother’s parenting and her child’s development.”
On a scale of 1 to 19, the average verbal IQ score for all 5-year old children in the study was 7.64. Children who had severely depressed mothers were found to have an average verbal IQ score of 7.30 compared to a score of 7.78 in children without depressed mothers.
“Although seemingly small, differences in IQ from 7.78 to 7.30 are highly meaningful in terms of children’s verbal skills and vocabulary,” said East. “Our study results show the long term consequences that a child can experience due to chronic maternal depression.”
At least half of the mothers in the study were rated as depressed based on their answers to questions such as “Are you sad?” and “Do you find yourself crying?”
“For mothers in the study, there were many stressors in their lives. Most of the mothers, while literate, had only nine years of education, were not employed outside the home and often lived with extended family in small, crowded homes — factors that likely contributed to their depression,” said East. “Many mothers suffer from depression in the first six months after childbirth, but for some, depression lingers.”
Research has shown that approximately 20 percent of mothers who are severely depressed when their child turns one-year old remain depressed for a long time.
“For health care providers, the results show that early identification, intervention and treatment of maternal depression are key,” said East. “Providing resources to depressed moms will help them manage their symptoms in a productive way and ensure their children reach their full potential.”
In the future, the researchers plan to further analyze the data to better understand how a mother’s depression may affect the child’s own depressive symptoms, as well as his or her academic achievement and health, such as the likelihood of being overweight or obese.
Roughly one in 10 women in the United States will experience depression, according to the Centers for Disease Control and Prevention.