People who are clinically depressed tend to see the outside world through the prism of their interior sadness. To demonstrate that effect, scientists show them pictures of others and ask them to match facial expressions to emotions. Depressed teen-agers and adults tend to interpret happy facial expressions as neutral and neutral expressions as sad, a phenomenon researchers call negative bias.
But investigators at Washington University School of Medicine in St. Louis have found some striking differences in how children with symptoms of depression interpret facial expressions. Unlike depressed teen-agers and adults, children aren't more likely to read more negative content into emotions. But they're exceptionally good at identifying the ones they do see. The researchers reported their preliminary results in October 1999 at the annual meeting of the American Academy for Child and Adolescent Psychiatry and the Canadian Academy of Child Psychiatry in Chicago.
Lead investigator Christine Mrakotsky and colleagues tested 20 children between the ages of 4 and 5-1/2. Eleven had symptoms of depression. The other nine were age-matched control subjects. Each of the children was given the Facial Affect Comprehension Evaluation (FACE) test. They were asked to find identical faces in a series of blurred photographs of faces. They also were instructed to match happy, sad, angry, scared and surprised faces to a list of those emotions. And the children were asked to recognize from facial expressions seven emotions and to verbally label these emotions: happiness, sadness, fear, anger, surprise, disgust and shame.
"They were more accurate than controls in identifying negative emotions, especially emotions such as sadness, shame and fear," said Mrakotsky, a research associate in Washington University's Early Emotional Development Program. "An emotion such as shame is very complex, so we would have expected it to be difficult for a child of 4 or 5 to identify it. But the children with symptoms of depression were quite able to identify these emotions."
In all, the preschoolers with depressive symptoms recognized and labeled significantly more emotional expressions than the control children. They also recognized significantly more sad emotions and so-called "internal" emotions such as shame or fear. And they scored slightly higher in recognizing anger and disgust, but there were no differences in recognizing positive emotions such as happiness and surprise.
"Whereas depressed adults tend to reflect their negative emotions in these kinds of tests by perceiving most emotions as sadness, the children did not blur out any emotions," Mrakotsky said.
"They were more accurate than other children in recognizing negative emotions but did not show the negative bias observed in adults. In that way, children with depressive symptoms seem to differ qualitatively in their recognition of emotions from adults with major depression."
Mrakotsky is careful to say that the children in the study had symptoms of depression rather than that they were depressed because it is not clear that such young children can get depressed. These experiments were conducted as part of a larger, comprehensive study that hopes to determine whether young children truly can suffer from clinical depression.
Child psychiatrist Joan Luby, M.D., is principal investigator of that five-year study funded by the National Institute of Mental Health. An assistant professor of child psychiatry, she also directs the Washington University Early Emotional Development Program.
"The main questions have to do with defining depressive syndromes in preschool children, if in fact, they can be identified and defined," Luby explained. "This study of emotional recognition does lend some validity to the idea that children we have identified as appearing to be depressed are somehow different from normal controls. They certainly seem to have different capabilities for recognition of emotion."
Whether those differences actually represent major depression is still unknown. "Our children are probably different in that they show depressive symptoms," Mrakotsky said. "However, we are not yet able to say whether this will develop into a disorder like major depression over a long time period."
Defining the symptoms
How long symptoms persist is important. In adults, a depressive episode must last at least two weeks before a patient officially can be diagnosed as depressed. That is a lot longer in the life of a three-year-old than in the life of an adult.
Other symptoms like lethargy, sadness and sleep problems are easy to spot in a full-grown human, but what are their equivalents in small children? And because in many physiological and psychological ways children are not simply miniature adults, is it necessary to find childhood equivalents of adult symptoms to diagnose depression?
Luby, Mrakotsky and colleagues say more study is needed before they can answer those questions. They hope to test a larger number of children with the FACE protocol and to follow children and their families for several months or years to learn whether depressive symptoms get better or worse over time. In addition, they are studying genetic family histories, various biological measures and other clues about whether what they have observed in young children truly represents major depression.
"We want to know how these children respond to things that normally induce joyful responses. We're also looking at biological measures such as the response of stress hormone levels to things like a brief separation from a caregiver," Luby said. "There is a whole constellation of developmental, emotional and behavioral measures involved, and we're hoping that certain key symptoms will emerge that essentially will define a psychiatric syndrome." Responses to facial expressions may be an indicator that something unique about emotional development distinguishes these children from other children.
Materials provided by Washington University In St. Louis. Note: Content may be edited for style and length.
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