Long-term depression in the mother may affect the child's IQ

According to a recent US study, maternal depression can have a negative effect on a child's cognitive development up to the age of 16.

Depression is a disease that affects all ages, from childhood to very late in life. In France, it is estimated that almost one in five people have suffered or will suffer from depression during their lifetime. The consequences, however, can extend to their children and negatively affect their cognitive development of a child until the age of 16, reveals a new American study published in the journal Child of Development.

Conducted by researchers from the University of San Diego School of Medicine (California, USA), the study involved interviewing a cohort of 900 healthy children and their mothers, at intervals period of 5 years, from infancy to 16 years old. The participants all lived in Santiago, Chile. Children were assessed for their verbal cognitive abilities using standardized IQ tests during each assessment. Mothers have been tested for the symptoms of depression.

An impact on IQ between 1 to 16 years

"We found that very depressed mothers did not invest as much as mothers with good mental health in materials to support the child's learning, such as toys and books, which had an impact on IQ. of the child at the age of 1, 5, 10 and 16 years old, "says Patricia East, PhD, a research scientist in the pediatric department of the San Diego School of Medicine and lead author of the study.

The stress that causes depressive symptoms

On a scale of 1 to 19, the average verbal IQ for all children in the study at age 5 was 7.64. During their research, the researchers found that children whose mothers were severely depressed had an average verbal IQ of 7.30, slightly less than children whose mother was not depressed (7.78 on average ). "Although seemingly small, IQ differences of 7.78 to 7.30 are very significant in terms of children's verbal skills and vocabulary," Pr East explained.

In this study, the emotional state of mothers was assessed via questions about emotional well-being. From their answers, the researchers were able to establish the reasons for the psychic state of distress of these mothers. "The women in our study are subject to many stressors on a daily basis.Most mothers, although illiterate, have not been able to go to long-term education, have no job at home. They often lived with their families in small, overcrowded homes - factors that probably contributed to their depression, "says Pr East.

Chronic maternal depression

The researcher also notes that while many mothers experience postpartum depression in the first six months after giving birth, depression may persist beyond this period for some. About 20% of mothers are still severely depressed when their child is 1 year old, the study says.

In light of these findings, the researchers indicate that they intend to do further work later to determine how maternal depression affects children's depressive symptoms during childhood and adolescence. "Providing resources to depressed mothers will help them manage their symptoms productively and ensure their children reach their full potential," Pr East says.