Most studies looking at the physical effects maternal depression has on the children of depressed women focus on the hippocampus, an area of the brain in charge of memories. In people who suffer from depression, the hippocampus tended to be smaller than average.
But a new study looking at the children of depressed women found a different reshaping of the brain.
The area of the brain in charge of scanning the environment for threats was nearly 20 percent larger in kids whose moms were depressed than the rest of the group.
The study, led by Sonia Lupen of the Universite de Montreal, was published this week in the Proceedings of the National Academy of Sciences. The researchers examined the brains of 17 children whose mothers had suffered depression since their birth in 1996. They looked at another 21 same-age children whose mothers had not been depressed. The kids of depressed women had amygdala that measured, on average, 1086 cubic centimeters, while those in the other children averaged 879.
What’s particularly interesting is that this size difference is in line with previous findings in studies of children from notorious Romanian orphanages in the 1990s, where they had been almost completely deprived of human touch and anything resembling maternal care.
Yikes! How depressing …
Granted, the study is small. And it’s not clear how “maternal depression” was quantified. Do occasional bouts count? Or did they find a group who couldn’t get out of bed for days and weeks. Were any of the depressed moms getting treatment. If so, did that make a difference? Did the presence of other caregivers ameliorate the effects? Did these women suffer depression in pregnancy as well?
Though, as lead author Lupen points out, it would follow that, in terms of ensuring survival, a baby not reassured of getting the consistent care (read: protection) from its primary caregiver would find a way to kick into high gear a way of finding danger on its own.
From the Daily Beast:
“If you grow up in an environment in which you don’t have all the support you would need, especially to help you evaluate the environment, maybe you become a super-detector of threats,” suggests Lupien. “We think it might lead to resilience.”
One way this particular area might be getting enlarged is through a repeated chemical release triggered by the amygdala.
One way that might happen is by flooding the brain with stress hormones called glucocorticoids, whose production the amygdala triggers. Levels of these hormones in the children of depressed mothers soared when they were put in an unfamiliar situation, showing that their stress-response system goes into overdrive at the slightest provocation. Since it’s the amygdala that processes the feeling of threat, a larger amygdala might be the equivalent of having not one fire alarm but many go off at the slightest whiff of smoke.
As if being a depressed mom isn’t a drag enough, knowing that you’re screwing with the shape of your kid’s brain is a big downer. But we should keep in mind that this is just one study. If the conclusions of this study prove to be true, however, it would be yet another reason for early screening of depression in women and also for support and treatment for them not just months but years after having kids.
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