DSM-5
Anorexia nervosa is classified under the Feeding and Eating Disorders in the latest revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM 5). There is no specific BMI cut-off that defines low weight required for the diagnosis of anorexia nervosa.The diagnostic criteria for anorexia nervosa (all of which needing to be met for diagnosis) are:
Restriction of energy intake relative to requirements leading to a low body weight. (Criterion A)
Intense fear of gaining weight or persistent behaviors that interfere with gaining weight. (Criterion B)
Disturbance in the way a persons weight or body shape is experienced or a lack of recognition about the risks of the low body weight. (Criterion C)Relative to the previous version of the DSM (DSM-IV-TR), the 2013 revision (DSM5) reflects changes in the criteria for anorexia nervosa. Most notably, the amenorrhea (absent period) criterion was removed. Amenorrhea was removed for several reasons: it does not apply to males, it is not applicable for females before or after the age of menstruation or taking birth control pills, and some women who meet the other criteria for AN still report some menstrual activity. Subtypes
There are two subtypes of AN:
Binge-eating/purging type: patients with anorexia could show binge eating and purging behavior. It is different from bulimia nervosa in terms of the individuals weight. An individual with binge-eating/purging type anorexia is usually significantly underweight. People with bulimia nervosa on the other hand can sometimes be normal-weight or overweight.
Individuals, particularly children experiencing abuse, may feel a loss of control over their life, circumstances, and their own bodies. Particularly sexual abuse, but also physical abuse, can make individuals feel that the body is not a safe place and an object over which another has control. Starvation, in the case of anorexia, may also lead to reduction in the body as a sexual object, making starvation a solution. Restriction may also be a means by which the pain an individual is experiencing can be communicated. Sociological
Anorexia nervosa has been increasingly diagnosed since 1950; the increase has been linked to vulnerability and internalization of body ideals. People in professions where there is a particular social pressure to be thin (such as models and dancers) were more likely to develop anorexia, and those with anorexia have much higher contact with cultural sources that promote weight loss. This trend can also be observed for people who partake in certain sports, such as jockeys and wrestlers. There is a higher incidence and prevalence of anorexia nervosa in sports with an emphasis on aesthetics, where low body fat is advantageous, and sports in which one has to make weight for competition. Family group dynamics can play a role in the cause of anorexia including negative expressed emotion in overprotective families where blame is frequently experienced among its members. When there is a constant pressure from people to be thin, teasing and bullying can cause low self-esteem and other psychological symptoms.