Previous studies have led researchers to believe that individuals with social anxiety disorder or social phobia have too low levels of the neurotransmitter serotonin. A new study, however, shows that the situation is exactly the opposite. Individuals with social phobia make too much serotonin. The more serotonin they produce, the more anxious they are in social situations. http://www.sciencedaily.com/releases/2015/06/150617115327.htm