Epidemiology
Although no broad-based population epidemiologic studies had been conducted as of 2009, the lifetime prevalence of trichotillomania is estimated to be between 0.6% (overall) and as high as 1.5% (in males) to 3.4% (in females). With a 1% prevalence rate, 2.5 million people in the U.S. may have trichotillomania at some time during their lifetimes.
According to the Office of Rare Diseases of the National Institutes of Health trichotillomania is considered a rare disease which, according to their statistics, means that less than 200,000 people in the United States are affected by this disorder.
Trichotillomania is diagnosed in all age groups; onset is more common during preadolescence and young adulthood, with mean age of onset between 9 and 13 years of age, and a notable peak at 12–13. Among preschool children the genders are equally represented; there appears to be a female predominance among preadolescents to young adults, with between 70% and 93% of patients being female. Among adults, females typically outnumber males by 3 to 1.
"Automatic" pulling occurs in approximately three-quarters of adult patients with trichotillomania.
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