Social Phobia Patients Have Heightened Reactions to Negative Comments
• Science Update
In a study using functional brain imaging, NIMH scientists found that when people with generalized social phobia were presented with a variety of verbal comments about themselves and others ("you are ugly," or "he's a genius," for example) they had heightened brain responses only to negative comments about themselves. Knowledge of the social cues that trigger anxiety and what parts of the brain are engaged when this happens can help scientists understand and better treat this anxiety disorder.
Generalized social phobia (GSP) is the most common of all anxiety disorders. It is marked by overwhelming anxiety and self-consciousness in social situations. One approach to understanding anxiety disorders is to use functional brain imaging (fMRI) to explore how the brain responds to different types of social signals. fMRI can provide information on the relative activity—and thus the engagement—of different parts of the brain by tracking the local demands made for oxygen delivered by circulating blood. Scientists using this technology have reported, for example, that people with GSP have heightened responses to a variety of positive, negative, and neutral facial expressions, not just expressions that others perceive as threatening.
Results of this Study
People with GSP had heightened responses to negative comments (relative to a comparison group without the disorder) in two brain areas: the first, the medial prefrontal cortex (MPFC), is involved in the sense and evaluation of self; the second, the amygdala, is central to emotional processing. The responses revealed by scanning paralleled the participants' self-report of how they felt after seeing the various positive, negative, and neutral comments presented.
This work, conducted by NIMH intramural investigators Karina Blair, Ph.D., Daniel Pine, M.D., and colleagues, provided information on the specific social cues that trigger anxiety in people with GSP. It adds to previous evidence that the amygdala is involved and, in implicating the MPFC, gives clues for further research to explore on how people with GSP interpret social cues. Functional brain scanning can thus help to define patterns of brain functioning that underlie anxiety disorders, providing information that can inform treatment.
A previous study by these investigators found that the reaction of the brain to facial expressions was different in people with GSP than in those with general anxiety disorder (GAD). This suggests that the two disorders do not represent mild and severe forms in a single spectrum of anxiety disorders, but two neurologically different disorders.
Continuing research will reexamine these differences to see if they occur across different tasks, providing confirmation for understanding them as different disorders, which could lead to more targeted and effective forms of treatment for each disorder. Future studies will also explore more deeply the nature of the thought process underlying the reaction of people with GSP to negative comments about themselves and the interaction of the amygdala and MPFC. Finally, brain scanning offers a means to study the effects of treatment; scanning can, for example, provide information on the effects of medications in these parts of the brain.
Blair, K. et al. American Journal of Psychiatry. 2008 Sep;165(9):1193-202. Epub 2008 May 15. PMID: 18483136
Blair, K. et al. Archives of General Psychiatry. 2008 Oct;65(10):1176-1184.