Social anxiety disorder (SAD) is the most common anxiety disorder. SAD is generally considered a chronic disorder and has its onset during early adolescence. It is a risk factor for subsequent depressive illness and substance abuse. Patients with SAD have an extreme fear of being negatively evaluated in social situations and, as a result, avoid social events or endure them with excessive fear or anxiety. Although the etiology of SAD is not yet fully established, twin and family studies suggest that SAD is heritable. Functional neuroimaging studies point to increased activity in amygdala and insula in patients with social anxiety disorder. In addition, there is evidence from various studies, that the serotonin, and dopamine neurotransmitter systems mediate the symptoms of SAD. A range of effective cognitive behavioural and pharmacological treatments now exists. However, they don't work for the 30-40% of patients.