teria for BN include recurrent episodes of both binge eating and compensatory behaviors such as purging, fasting, or exercising to prevent weight gain; behaviors occur at least twice a week for three months minimum. Self-evaluation is again dependent on body weight and shape. Binging and purging are also characteristic of a type of AN and a subtype of BN includes a non-purging type, complicating the diagnosis of each (APA, 1994; Polivy, 2002).
Incidence of both disorders has increased over the last 50 years, with prevalence rates estimated to range from 3% to 10% of at-risk females between ages 15 and 29 years. BN patients outnumber AN patients by two to one. Reasons for the increase in incidence may be due to the increased awareness and reporting of the disorders. About a third of patients meet diagnostic criteria for a five-year or longer period even after treatment. Mortality rates range from 5% to 8%, however it is also estimated that 50% of patients improve following the five-year period after treatment begins (Polivy, 2002). In a sample of university students, out of 578 who completed the survey, 17% had eating disorders. Those with the disorders were younger, white, in a sorority, and Christian (Prouty, Protinsky, & Canady, 2002). Studies of undergraduate women show that 64% have engaged in disordered eating behaviors and more than half skipped meals (59%); one third restricted calorie intake (37%), eliminated fats (30%), and eliminated carbohydrates (27%); and one fourth fasted for more than 24 hr (26%) (Moradi, Dirks, Matteson, 2005).
Eating disorders have a high comorbidity with psychiatric disorders (Pearlstein, 2002). For example, patients with AN or BN tend to also suffer from depression, anxiety disorders, substance abuse, obsessive-compulsive disorders, personality disorders, and childhood sexual abuse. Pearlstein stated that lifetime prevalence rates of major depression in AN patients are 46-74% and...