Anxiety disorders are the most prevalent of all mental disorders in the Western world. An estimated 20% of all people will develop an anxiety disorder during their lifetime. Most anxiety disorders have their onset during childhood and adolescence, affecting more women than men.

With lifetime histories of 9.2% and 7.9% respectively, social phobia (a fear of rejection and humiliation in social situations) and specific phobia (e.g. fear of spiders, fear of flying or claustrophobia) are the most common anxiety disorders, with generalised anxiety disorder (GAD or "worry disorder") and panic disorder also being quite prevalent (From: Nemesis-2 Trimbos Institute).

Yet, even though anxiety disorders are so common, about half of all people suffering from an anxiety disorder do not receive adequate treatment (Wang et al., 2005), which needlessly prolongs the duration of their symptoms, only exacerbating existing feelings of stress and increasing the social burden. In 2004, Australian researchers already estimated that if all patients were to receive proper treatment for their anxiety disorder, this would reduce both the total disease burden and treatment costs by 40% (Andrews et al., 2004).