The researchers are hopeful that the study could pave way for potential diagnosis and treatment of such mental disorders together with changing our perception of how brain processes emotions in everyday life.
Generalized anxiety disorder (GAD) is a mental disorder characterized by excessive, uncontrollable, and often irrational worry about everyday matters such as health, money, relationships, family problems, or work difficulties.
The symptoms include fatigue, headaches, nausea, numbness in hands and feet, muscle tension, muscle aches, difficulty swallowing, bouts of difficulty breathing, irritability, sweating, insomnia, hot flashes, and rashes.
GAD patients examined
To come up with this finding, a research team from Stanford University School of Medicine (SUSM) examined 17 people with GAD, and compared them with 24 healthy participants.
The researchers used a brain imaging technique called functional magnetic resonance imaging (fMRI), and a behavioral marker to study and compare the brain activity of the participants while they performed an emotion-based task.
For the study, both the groups were asked to view several images of happy, or fearful faces, superimposed with words like “fear” or “happy.”
Some of the images were also overlaid with unmatched words. For instance, some happy faces featured the word “fear” while some sad faces featured “happy.”
Then the participants in both the groups were asked to identify the expression of each face shown in the images using a button box.
People with anxiety disorder over-react
On analysis of the brain scans, the researchers found that all the participants, whether GAD patients or healthy people, were able to correctly identify the expressions on the faces of the images.
Compared to the subjects with the anxiety order, healthy people reacted more quickly to the images with unmatched words even when the previous image was incongruent.
But as not all the images were overlaid with matched words, this created an emotional conflict among the GAD patients.
Therefore, the reaction time effect as seen in the healthy participants was found to be absent among the GAD patients. And when the anxious patients were asked to view two incongruent images at a time, the reaction time noted was worse.
Overall, both groups of participants were able to register negative emotions. However, the healthy patients were found to better control their reactions unlike the GAD patients who had a tough time controlling their reactions.
The participants were later asked whether they were aware of any patterns which might have aided, or marred their performance. All of them replied in negative, thus implying that their brain was unconsciously controlling all the emotions, the researchers concluded.
"Patients experience anxiety and worry and respond excessively to emotionally negative stimuli, but it's never been clear really why," said Amit Etkin, assistant professor of psychiatry and behavioral sciences, who led the study.
"GAD patients had decreased ability to use emotional content from previous stimuli to help them with the task," said Etkin.
The study appears in this month’s online edition of the American Journal of Psychiatry.
Post new comment