Anxiety disorders affect approximately 40 million people in the United States each year. Over a lifetime, one source estimates that approximately 16.6% of people worldwide will experience an anxiety disorder. Approximately 75% of anxiety disorders first develop by the age of 21.5, and women are twice as likely as men to develop an anxiety disorder.
Specific Phobias
One year prevalence of specific phobias is estimated by different sources at approximately 3.0%. Lifetime prevalence appears to be approximately 5.3%. However, rates vary widely in different countries, from 0.2% in Northern Ireland to approximately 8.8% in the United States. Specific phobias often begin in childhood, often around the age of seven years.
Women are two to four times more likely than men to develop a specific phobia. Rates appear to increase slightly from ages 18 to 64. In older adults, however, prevalence of specific phobias (along with other anxiety disorders) appears to drop dramatically. However, this may partly be due to underreporting of symptoms by older adults.
Social Phobias
World wide one year prevalence of social phobia is estimated by various sources at 4.5%, while lifetime prevalence appears to be approximately 3.6%. Again, rates vary drastically from 0.53% in Korea to 45.6% in Udmurtia, Udmurt Republic (a sovereign republic within the Russian Federation). In the United States, it is estimated that approximately 6.8% of the population suffer social phobia in a given year. Social phobias typically develop at approximately 13 years of age.
Studies are not clear on possible gender differences in rates of social phobias. Rates appear to slightly decrease from ages 18 to 64, with a marked drop after the age of 65.
Agoraphobia
Some sources estimate that one year prevalence of agoraphobia is approximately 1.6%, while lifetime prevalence is approximately 3.6%. Rates do not vary as dramatically between countries as those of other types of phobia. In the United States, one year prevalence is approximately 0.8%. Agoraphobia typically appears at approximately 20 years of age.
Women are two to four times more likely to develop agoraphobia. Lifetime prevalence rates appear to stay stable from ages 18 to 64. Rates drop off in the elderly.
Conclusion
It appears that cultural factors may have an effect on phobias. Dramatically different rates of phobias have been reported in different countries. More research is necessary to narrow down the effects of age, gender and culture on the development of phobias.
Sources:The Numbers Count: Mental Disorders in America. National Institute of Mental Health. February 15, 2008. http://www.nimh.nih.gov/health/publications/the-numbers-count-mental-disorders-in-america.shtml#KesslerPrevalence
Somers MSc, PHD, Julian, Goldner MHSc, MD, Elliot, Waraich MHSc, MD, Paul, Hsu MSc, Lorena. Prevalence and Incidence Studies of Anxiety Disorders: A Systematic Review of the Literature. Canadian Journal of Psychiatry. February 2006. 51:2. pp. 100-113. February 19, 2008.
Pontillo PhD, Deborah, Lang PhD, Ariel and Stein MD, Murray. Management and Treatment of Anxiety Disorders in the Older Patient. Journal of Clinical Geriatrics. October 2002. 10:10. February 19, 2008.
