Teens With Bipolar Disorder Misinterpret Facial Expressions

(HealthDay News) -- A new study may explain why children with bipolar disorder tend to be more aggressive and irritable and have poorer social skills than healthy children.

The study, conducted at the U.S. National Institute of Mental Health, shows that bipolar youths misinterpret facial expressions to be hostile more often than their healthy counterparts. This misinterpretation could explain the mania and depression that plague many children with bipolar disorder, and cause problems with friendships, school and family.

The findings were reported in this week's issue of Proceedings of the National Academy of Sciences.

"Since children seem to have a more severe form of the disorder, they may provide a clearer window into the underlying illness process than adult onset cases," explained Dr. Ellen Leibenluft of the NIMH's Mood and Anxiety Disorders Program. "Our results suggest that children with bipolar disorder see emotion where other people don't. Our results also suggest that bipolar disorder likely stems from impaired development of specific brain circuits, as is thought to occur in schizophrenia and other mental illnesses."

Researchers also discovered that the left amygdala, which registers fear in the brain, reacted more in children with bipolar disorder than those without when they were asked to rate the hostility of a neutral facial expression vs. a non-emotional feature. The more a child viewed the expressions as hostile, the more reaction was seen in the amygdala.

This brain activity was measured using MRI in 22 bipolar children and 21 healthy children. Researchers noted that other areas of the brain related to emotions, including the nucleus accumbens, putamen, and left prefrontal cortex, also showed higher activity levels in the bipolar subjects when they considered a face to be hostile. Activity was no different between bipolar and healthy children when rating non-emotional features, which confirms that the differences between the groups of children are specifically related to emotional processes.

"By finding a brain imaging trait that may be more selective than current clinical criteria, this line of research might help us refine our definition of pediatric bipolar disorder," said NIMH director Dr. Thomas Insel. "The researchers are following up with imaging studies of children with bipolar spectrum disorders and healthy children who are at genetic risk for developing the disorder to see if they also have the same amygdala over-activation."

More information
For more on bipolar disorder, head to the U.S. National Institute of Mental Health.