The children of mothers who experience depression up to three months after giving birth are at greater risk than other children for exhibiting serious violent behavior as 11-year-olds, according to a new study in APA's Developmental Psychology (Vol. 39, No. 6).
Participating children with mothers who experienced postpartum depression and at least one later episode of depression were four times more likely to act out violently and nine times as likely to use weapons such as bricks and bats in confrontations with other children and adults. For the study, psychologist Dale Hay, PhD, of Cardiff University in Wales and her collaborators followed 132 South London families for 12 years.
They assessed the self-reported mental health of the mothers through the Clinical Interview Schedule, a structured interview used to identify mood and other disorders. When children reached their 11th birthday, researchers assessed their psychological functioning and problem behaviors using a battery of tests including the Child and Adolescent Psychiatric Assessment, a structured Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition)-based diagnostic interview and the Strengths and Difficulties Questionnaire, which measures a child's problem behaviors from the perspective of the child, the mother and the class teacher.
While many of the children who exhibited clinically significant levels of violence at age 11 had been raised by mothers who had postpartum depression, maternal depression that occurred only later in the child's development did not significantly correlate with violent acting out.
According to Hay, infants learn to direct attention and control their emotions through early interactions with caregivers. Depressed mothers may not have the emotional resources to interact with their babies in such a way that promotes development of these important skills, he says, creating deficits that could lead to violence later in the child's life.
"Calming down an infant and helping infants learn to calm themselves is a very difficult task," says Hay. "Depressed mothers may find it especially difficult."
However, it is equally possible, says Hay, that children who later behave violently were difficult as infants, distressing their mothers and contributing to a relatively high incidence of maternal depression.
Whether depressed mothers tend to raise difficult children or difficult children tend to depress their mothers, this research shows that postpartum depression can serve as a warning that a particular child is at elevated risk for developing serious behavior problems. This knowledge, says Hay, could be used to target both mothers and children for critical early intervention.