Children with depressed parents get stressed out more easily than children with healthy parents—if the depressed parents are negative toward their child. That’s the conclusion of a study published in an upcoming issue of Psychological Science, a journal of the Association for Psychological Science.
The study is part of a long-term look at how a child’s early temperament is related to the risk for depression. The children were recruited for the study when they were three years old, an age when depression is rare. Thus, the researchers expect to see depression appear as the children grow.
At the time of this study, the children were three years old and none of them had shown signs of depression. Instead, the researchers were measuring how much the children were upset by stressful situations. The study was by Lea Dougherty of the University of Maryland and Daniel N. Klein, Suzanne Rose, and Rebecca S. Laptook of Stony Brook University.
In one test, the experimenter brought the child into the room and then left them alone saying they’d forgotten something. Then a male stranger comes into the room, talks to the child, and approaches them. This makes most kids nervous. Other tests were more geared at frustration. For example, giving the child an appealing toy locked in a clear box, and then giving them keys that don’t fit the lock or giving them an empty box all wrapped up like a present. “After each one of these, you come back in, and you’re like, ‘Oh, my gosh, I forgot the present! Here it is,'” Dougherty says. “Everything’s kind of remedied.” In between the stress tests, the children had fun with the experimenter, playing toys and doing more fun tests.
Twenty or 30 minutes after each stress test, the experimenter took a saliva sample from the child to measure their levels of the stress hormone cortisol. During another visit, researchers observed a parent, usually the mom, reading a book to the child and doing a task together. They looked at how the two interacted, including hostility—any frustration, anger, annoyance, or critical comments were observed. “Any type of negativity that’s directed at you from your caregiver in this type of context is very meaningful information,” Dougherty says.
The researchers found that kids who had the biggest stress response were those whose mothers had been depressed at some point in the child’s three years of life and whose parents were hostile when playing with their children. The researchers didn’t see enough fathers to get a sense of how they interact with children, and depression was less common among dads, too.
These conclusions are only about stress, but stress is a risk factor for depression. This could show one way in which a parent’s depression could lead to depression in the child. Children may also inherit depression with their parents’ genes, Dougherty says, but this suggests another way that parents can affect their child. “I think it’s actually quite hopeful, because, if we focus on the parenting, we could really intervene early and help parents with chronic depression when they have kids,” Dougherty says.