Who develops anorexia nervosa?
Like all eating disorders, anorexia nervosa tends to occur in pre- or post-puberty, but can develop at any major life change. Anorexia nervosa predominately affects adolescent girls and young adult women, although it also occurs in men and older women. One reason younger women are particularly vulnerable to eating disorders is their tendency to go on strict diets to achieve an "ideal" figure. This obsessive dieting behavior reflects today's societal pressure to be thin, which is seen in advertising and the media. Others especially at risk for eating disorders include athletes, actors, dancers, models, and TV personalities for whom thinness has become a professional requirement. For the person with anorexia nervosa, the satisfaction of control achieved over weight and food becomes very important if the rest of their life is chaotic and emotionally painful.
What are the causes of anorexia nervosa?
Knowledge about the causes of anorexia nervosa is inconclusive, and the causes may be varied. In an attempt to understand and uncover the origins of eating disorders, scientists have studied the personalities, genetics, environments, and biochemistry of people with these illnesses. Certain personality traits common in persons with anorexia nervosa are low self-esteem, social isolation (which usually occurs after the behavior associated with anorexia nervosa begins), and perfectionism. These people tend to be good students and excellent athletes. It does seem clear (although this may not be recognized by the patient), that focusing on weight loss and food allows the person to ignore problems that are too painful or seem unresolvable.
Eating disorders also tend to run in families, with female relatives most often affected. A girl has a 10 to 20 times higher risk of developing anorexia nervosa, for instance, if she has a sibling with the disease. This finding suggests that genetic factors may predispose some people to eating disorders. Behavioral and environmental influences may also play a role. Stressful events are likely to increase the risk of eating disorders as well. In studies of the biochemical functions of people with eating disorders, scientists have found that the neurotransmitters serotonin and norepinephrine are decreased in those with anorexia, which links them with patients suffering from depression. People with anorexia nervosa also tend to have higher than normal levels of cortisol (a brain hormone released in response to stress) and vasopressin (a brain chemical found to be abnormal in patients with obsessive-compulsive disorder).
