People suffering generalised social phobia experience increased brain activity when confronted with threatening faces or frightening social situations, new research shows.
The finding could help identify how severe a person's generalised social phobia is and measure the effectiveness of pharmacological and psychological treatments for the condition.
Up to one million Australians suffer from social phobia at any one time, making it the most common anxiety disorder, and the third most common psychiatric disorder after depression and alcohol dependence.
People with generalised social phobia experience heightened anxiety during potential or perceived threatening social situations. They generally avoid eye contact and fear any interpersonal situation.
The research, to be published in the journal Biological Psychiatry, was conducted by an international team of researchers, including Associate Professor Pradeep Nathan from Monash University's Centre for Brain and Behaviour and the Department of Physiology.
The researchers found that the area of the brain called the amygdala becomes increasingly hyperactive when patients look at threatening, angry, disgusted or fearful faces. Further, they found that the increased response in the amygdala correlated with the patients' level of social phobia symptoms.
The amygdala is in the limbic part of the brain, which controls emotions and sends messages to the parts of the brain controlling breathing and heart rate.
Using functional magnetic resonance imaging, the researchers compared brain activity when people with generalized social phobia looked at threatening faces compared to happy or neutral faces.