Diagnosing depression before it starts.

• Position: Pediatric Brain Scans

A screen that could identify children at high risk of developing depression later in life may be the result of a brain imaging study from the Massachusetts Institute of Technology, Cambridge, Mass., and Harvard Medical School, Boston, in which researchers found distinctive brain differences in children known to be at high risk because of family history of depression.

The finding suggests that this type of scan could be used to identify children whose risk previously was unknown, allowing them to undergo treatment before developing depression, says coauthor John Gabrieli, professor of brain and cognitive sciences and a member of MIT's Institute for Brain Research.

"We'd like to develop the tools to be able to identify people at true risk, independent of why they got there, with the ultimate goal of maybe intervening early and not waiting for depression to strike the person." Early intervention is important because, once a person suffers from an episode of depression, they become more likely to have another. "If you can avoid that first bout, maybe it would put the person on a different trajectory," indicates Gabrieli.

The study also helps to answer a key question about the brain structures of depressed patients. Previous imaging studies have revealed two brain regions that often show abnormal activity in these patients: the subgenual anterior cingulate cortex (sgACC) and the amygdala. However, it was unclear if those differences caused depression or if the brain changed as the result of a depressive episode.

To address that issue, the researchers decided to scan brains of children who were not depressed...