Both proposed that it was a mental rather than a physical or organic disorder. In 1930 John Mayo Berkman of the Mayo clinic reported the first long term study on a large number of anorexia patients (Cassell & Gleaves, 2006). .
The incidence of anorexia has gone up since 1960, but has then leveled out. It has also been found that it has spread geographically. In recent years researchers have found an increase in the male population as well. In 1994, Vandereyken and Van Deth proposed that anorexia has become a fashionable illness for the public and was not being treated well (Cassell & Gleaves, 2006). .
Anorexia is an interesting disorder in that the prevalence of the disorder has not changed over the years as it has been studied. Anorexia nervosa affects 0.9-2.2% of women over a lifetime. The prevalence of subclinical levels are much higher. The prevalence is much lower in men, about 0.3%. Onset is usually around the teenage years, from about 14-19. This is the same for both men and women (Watson & Bulik, 2013). The prevalence of anorexia nervosa has been shown to be different between different ethnicities. Caucasian females are at the highest risk, while Asian females have the lowest rate of anorexia nervosa. Anorexia is also very uncommon in African Americans (Woerwag-Mehta & Treasure, 2008).
The American Psychiatric Society first recognized anorexia nervosa in the fourth edition of the Diagnostic and Statistical Manual. The criteria to be diagnosed with anorexia have changed since then and are now updated in the fifth edition. Now in the DSM V these criteria have changed so they can better diagnose individuals with this disorder. The changes were minor but very important in the diagnosis of certain individuals. Criterion A focuses on behavior and instead od saying that these people "refuse" the intake of food, it now says that they restrict their caloric intake. Criterion D requires amenorrhea, or the absence of at least three menstrual cycles.
