At least they don't do twice the damage

Children growing up in poverty are more prone to slow intellectual development, and those whose mothers are depressed are more likely to be badly behaved, says a research team from the University of York.

But children growing up in households experiencing both problems at once are not at any greater risk.

By Kathleen Kiernan and Fiona Mensah from the Department of Social Policy, the York research was based on data on nearly 15,000 children, drawn from the Millennium Cohort Study, a representative sample of babies born in the year 2000. Information was collected from families when children were between the ages of nine and 11 months and again when they were three.

The conclusion that family poverty and children’s cognitive development are linked is nothing new; several decades of research have established this beyond doubt. Nevertheless, say the authors, it is striking that by the tender age of three 26% of children living in persistently poor households are showing signs of cognitive delay. This translates to 4% of all children in that age group.

Previous studies have also shown that children with depressed parents are more likely to have developmental issues. In this case, cognitive development was assessed by examining children’s comprehension of colors, letters, numbers, sizes and the comparison of objects and a shapes. A standardized questionnaire was used to gauge behavior.

When the team looked at the association between maternal depression and cognitive development, they were surprised to find that it made no impact. Children with depressed mothers were just as ready to start school as their contemporaries. Behavior was a different story, however. Children with depressed mothers were much more likely to be behaving badly, even at such an early age.

Whether these problems were permanent or fleeting also made a difference to children. Long-term poverty was worse for their intellectual growth, and persistent maternal depression more detrimental to behavior. Short episodes certainly made an impact but it was less marked.

But the two issues did not have any compound effect, reinforcing the message that “poverty matters more for a child’s cognitive development, and maternal depression impacts more on children’s behavior problems”.

Children with a depressed mother in a poor household had the same cognitive delay as those from poor families whose mothers’ mental health was unconcerning. Equally, children in poor households with depressed mothers had similar levels of behavior problems as kids with similarly depressed mothers from rich homes.

Family structure made no difference to children’s development, backing the case for policies that support parents, irrespective of their living arrangements. [See: Does peace always mean burying differences? [1]]

Living with biological parents, married on unmarried, or with step families or just with mum had no implications for kids' intelligence or behavior.

Unraveling the links between the causes and effects of social problems can help sharpen policy decisions. With many efforts to bolster children’s outcomes focusing on pulling families out of poverty, these findings emphasize that a wider portfolio of interventions is needed to address the full range of developmental issues.

See: Kiernan K E and Mensah F K (2009), “Poverty, maternal depression, family status and Children’s Cognitive and Behavioral Development in Early Childhood: A Longitudinal Study,” Journal of Social Policy, 38, 4, pp 569-588