MRI reveals altered brain response to negative comments in people with social phobia
Magnetic resonance brain imaging reveals that patients
with generalized social phobia respond differently than others to negative comments
about themselves, according to a report in the October issue of Archives of General
Psychiatry, one of the JAMA/Archives journals.
"Generalized social phobia is characterized by fear/avoidance
of social situations and fear of being judged negatively by others," the authors
write as background information in the article. "It is the most common anxiety
disorder in the general population, with the lifetime prevalence estimated at
13.3 percent, and it is associated with a high risk for depression, alcohol and
drug abuse and suicide." Previous studies have found differences in the way brains
of affected individuals respond to facial expressions, suggesting that the condition
involves increased responsiveness to social stimuli in areas linked to emotion.
Karina Blair, Ph.D., and colleagues at the National Institute
of Mental Health, Bethesda, Md., compared functional MRI (fMRI) scans of 17 unmedicated
individuals with generalized social phobia to those of 17 controls who were the
same age and sex and had the same IQ but did not have the disorder. "During fMRI
scans, individuals read positive (e.g., You are beautiful), negative (e.g., You
are ugly) and neutral (e.g., You are human) comments that could be either about
the self or about somebody else (e.g., He is beautiful)," the authors write.
The patients with generalized social phobia showed increased
blood flow in their medial prefrontal cortex and amygdala-areas of the brain linked
to concepts of self as well as fear, emotion and stress response-when reading
negative statements about themselves. However, there were no differences between
the two groups in response to negative comments referring to others or neutral
or positive comments referring to either self or others.
"Given that medial prefrontal cortex regions are involved
in representations of the self, it might be suggested that these regions, together
with the amygdala, play a primary role in the development and maintenance of generalized
social phobia and that the pathology in the disorder at least partly reflects
a negative attitude toward the self, particularly in response to social stimuli?that
in generalized social phobia what engages the mind is others' criticism," the
authors conclude. "This highly context-dependent response in generalized social
phobia helps constrain existing models of the disorder and may thus guide future
therapeutic formulations in the treatment of the disorder."
This research was supported by the Intramural Research
Program of the National Institutes of Health, National Institute of Mental Health.
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