The amygdala, an almond-shaped brain structure that plays an important role in evaluating the emotional significance of daily events, malfunctions in children with severe symptoms of either anxiety or depression, according to preliminary brain-scan data.
Compared with children who have no psychiatric ailments, youngsters with anxiety disorders display an exaggerated amygdala response to fearful faces, whereas depressed kids show a blunted amygdala reaction to the same faces, reports a team led by psychologist Kathleen M. Thomas of Weill Medical College of Cornell University in New York City.
These findings, which appear in the November Archives of General Psychiatry, follow reports of unusual amygdala activity in adults with anxiety or depression.
For instance, heightened amygdala activity occurs in people with post-traumatic stress disorder when they view upsetting images. Other reports find elevated amygdala activity in depressed adults at rest.
Some anxious and depressed kids may display different types of altered amygdala activity than their adult counterparts do, Thomas' group says.
The researchers studied seven boys and five girls with severe anxiety or panic disorder, seven boys and five girls with no psychiatric disorder, and five girls with major depression. Participants, ages 8 to 16, underwent functional magnetic resonance imaging of their brains as they viewed pictures of scared-looking and neutral adult faces. This technology tracks changes in blood flow, an indirect reflection of brain-cell activity.
It's not clear whether the unusual amygdala responses reflect a biological vulnerability to childhood emotional disorders or instead develop as a consequence of severe anxiety or depression.
Kathleen M. Thomas
Sackler Institute for Developmental Psychobiology
Weill Medical College of Cornell University
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New York, NY 10021