According to a recent report in The Journal of Neuroscience, brain imaging has revealed a breakdown in normal patterns of emotional processing that impairs clinically depressed patients. When the patients viewed emotionally negative images and attempted to suppress their feelings, activity was enhanced in several brain areas, including the amygdala, which plays a role in generating emotion.
Tom Johnstone, Ph.D., along with his colleagues at the University of Wisconsin in Madison Wisc., and Tufts University in Medford, Mass., studied 21 adults diagnosed with major depressive disorder and 18 healthy subjects of comparable ages. Participants viewed a series of emotionally positive and negative images, indicating their reaction to each one. Four seconds after the presentation of each picture, participants were asked either to increase their emotional response, to decrease it, or simply to continue watching the image.
Johnstone and his colleagues recorded levels of emotional excitement by measuring pupil dilation and, throughout the test; a functional MRI scanner was utilized to image changes in neural activity.
Data showed patterns of activity in the ventromedial prefrontal cortex (VMPFC) and the right prefrontal cortex (PFC), areas that control emotional output generated from the amygdala. The VMPFC is compromised in depression, likely because of the engagement of right PFC circuitry in depressed individuals, according to the study.
“These findings underscore the importance of emotional regulation deficits in depression,” said Johnstone. “They also suggest targets for therapeutic intervention.”