One of the most frightening aspects of depression is the fact that, once someone suffers a depressive episode, they’re very likely to have another. And depression itself often brings other ills, from substance abuse to heart disease. For these reasons, mental health researchers have long worked on developing various tests to predict the risk of depression. If you could avoid letting people sink into major depression, the thinking goes, you could potentially prevent a lifetime of recurrent suffering.
A new study from MIT and Harvard, published in the journal Biological Psychiatry, suggests that children with a high risk of depression have brain changes that can be identified on MRI scans. This could lead to new screening tests for depression, which might lead to earlier and better interventions.
"We wanted to address if we can find ways to identify children who are at risk for developing depression with a goal of seeing whether you can help those children avoid depression altogether," says John Gabrieli, the MIT neuroscientist who led the study.
The study involved 27 children between the ages of eight and 14, all of whom were considered high-risk because of a family history of depression. Children who have a parent with depression are three or four times more likely than children with well parents to suffer depression themselves at some point in their lives, Gabrieli says. The children underwent functional MRI (fMRI) scans, which measured synchronization between different regions of the brain, telling researchers those parts of the brain that communicate with one another and how much.
A high percentage of the at-risk children had distinctive connections between certain parts of their brains when compared with a control group of children with no family history of depression. The two most notable links were between the brain’s subgenual anterior cingulate cortex (sgACC) and the default mode network, a part of the brain known to increase its activity when our minds wander. The other unusually strong connection was between the amygdala, the brain’s emotion processing center, and the inferior frontal gyrus, which processes language. In other areas of the brain, the at-risk group showed less connectivity than the control group.
Previous studies had shown similar patterns in the brains of depressed adults. But researchers hadn’t known whether these abnormalities were a cause of depression or an effect. This new research—on children who were at risk of depression but had not become ill yet themselves—suggests they may be a cause, an underlying issue with brain architecture or wiring.
The team plans to follow the at-risk children to see who actually develops depression, which will help make the screening more accurate. They're also planning a study to see if preventative treatments might help at-risk children avoid depression in adolescence or young adulthood. These treatments might include cognitive behavioral therapy, which helps people redirect their thoughts down more positive paths, or mindfulness, which trains the brain to slow down and focus on the present.
"[These] are things we know are effective that would be benign," Gabrieli says.
How potential screenings might be used in the future is not clear yet. There are possible ethical issues having to do with privacy, as Gabrieli notes. Could schools use depression screenings to weed out students who might become depressed and perform poorly in the future? Could employers?
"There’s a question of using this information responsibly," Gabrieli says. But, used carefully, he says it could be a "huge social good" for those at risk of an often devastating disease.