GAD is a common and disabling mental disorder associated with substantial medical and psychiatric comorbidity and occupational impairment. It is characterized by inappropriate or excessive anxiety and worrying that persists over time for more than six months. Common features include apprehension, with worries about future misfortune; inner tension and difficulty in concentrating; motor tension, with restlessness, tremor and headache; and autonomic anxiety symptoms, with excessive perspiration, dry mouth and epigastric discomfort. GAD is typically a chronic disorder with a high relapse rate and therefore requires effective long-term treatment. Long-term studies are necessary to demonstrate that the short-term effect is maintained.