Country Prevalence United States 2–7% England 0.4% (children) Scotland 1.8% (children) Wales 0.6% (children) Australia 1–2.7% Brazil 4.7–7.9% India 12.8% (adolescents) Iran 0.8% Israel 4.5% Nigeria 9.4% (university students) Sweden 15.6% (university students) Turkey 9.6% (university students) Poland 7–9% (2002) Taiwan 7% children (2002~2008)<unk>  is known to appear at an early age in most cases. Fifty percent of those who develop this<unk>  have developed it by the age of 11, and 80% have developed it by age 20. This early age of onset may lead to people with<unk>  being particularly vulnerable to depressive illnesses, substance use, and other psychological conflicts. When prevalence estimates were based on the examination of psychiatric clinic samples,<unk>  was thought to be a relatively rare<unk> . The opposite was found to be true;<unk><unk>  was common, but many were afraid to seek psychiatric help, leading to an underrecognition of the problem. The National Comorbidity Survey of over 8,000 American correspondents in 1994 revealed 12-month and lifetime prevalence rates of 7.9 percent and 13.3 percent, respectively; this makes it the third most prevalent psychiatric<unk>  after depression and alcohol use<unk> , and the most common of the<unk><unk> s. According to US epidemiological data from the National Institute of Mental Health,<unk>  phobia affects 15 million adult Americans in any given year. Estimates vary within 2 percent and 7 percent of the U.S. adult population. The mean onset of<unk>  phobia is 10 to 13 years. Onset after age 25 is rare and is typically preceded by panic<unk>  or major depression.<unk>  occurs more often in females than males. The prevalence of<unk>  phobia appears to be increasing among white, married, and well-educated individuals. As a group, those with generalized<unk>  phobia are less likely to graduate from high school and are more likely to rely on government financial assistance or have poverty-level salaries. Surveys carried out in 2002 show the youth of England, Scotland, and Wales have a prevalence rate of 0.4 percent, 1.8 percent, and 0.6 percent, respectively. In Canada, the prevalence of self-reported<unk><unk>  for Nova Scotians older than 14 years was 4.2 percent in June 2004 with women (4.6 percent) reporting more than men (3.8 percent). In Australia,<unk>  phobia is the 8th and 5th leading disease or illness for males and females between 15 and 24 years of age as of 2003. Because of the difficulty in separating<unk>  phobia from poor<unk>  skills or shyness, some studies have a large range of prevalence. The table also shows higher prevalence in Sweden.
Social anxiety disorder
Avoidant personality disorder
Separation anxiety disorder
Schizotypal personality disorder  Schizotypal disorder  1
Generalized anxiety disorder
Blood phobia
Body dysmorphic disorder
Somatization disorder