Causes
Eating disorders like Anorexia, Bulimia or Compulsive Overeating are complex diseases and not just a condition that can be treated with willpower. They meet the definition of a disease because, like other diseases, they have a particular destructive process for an individual, with a specific cause (that cause can be either known or unknown), and display characteristic symptoms. All eating disorders are primary diseases and not the secondary result of some other disorder. They are chronic conditions with an identifiable progression and predictable symptoms. Eating disorders arise out of the combination of genetic, sociological, and psychological factors.
Genetic
Many researchers believe that there is an inherited predisposition to having an eating disorder. Studies have shown that the co-occurrence of eating disorders such as Anorexia, Bulimia or Compulsive Overeating among identical twins is greater than the co-occurrence among fraternal twins. Since identical twins are genetically more similar than fraternal twins, this would support an inherited component. Other research on the genetic component of eating disorders has focused on neurochemistry. Researchers have found that the neurotransmitters serotonin and neuroepinephrine are significantly decreased in acutely ill patients suffering from Anorexia and Bulimia Nervosa. These neurotransmitters also function abnormally in individuals afflicted with depression. This leads some researchers to believe there may be a link between these two disorders. Besides creating a sense of physical and emotional satisfaction, the neurotransmitter serotonin also produces the effect of feeling full and having had enough food.
Other brain chemicals have also been explored for their possible role in eating disorders. Individuals with eating disorders like Anorexia, Bulimia or Compulsive Overeating have been shown to have a higher than normal level of the hormones vasopressin and cortisol. Both these hormones are normally released in response to physical and possible emotional stress, and may contribute to some of the dysfunction seen in eating disordered individuals. Other research has found high levels of the neuropeptide-Y and peptide-YY to be elevated in individuals suffering from Anorexia and Bulimia. These chemicals have been shown to stimulate eating behavior in laboratory animals. The hormone cholecystokinin (CCK) has been found to be low in women with Bulimia and has caused laboratory animals to feel full and stop eating.
Sociological
Environmental conditions reinforce the practice of an eating disorder like Anorexia, Bulimia or Compulsive Overeating. We live in a society that reinforces the idea to be happy and successful we must be thin. Today, you cannot read a magazine or newspaper, turn on the television, listen to the radio, or shop at the mall without being assaulted with the message that fat is bad. During adolescence, a particularly vulnerable time to the development of an eating disorder, the influence of peers becomes important. Self monitoring and comparing ourselves to others becomes central to our psyche. Peer teasing and pressures to conform to the norm are common in the background of eating disordered individuals. As our bodies developed and changed, how others and we reacted to these changes influenced our eventual body acceptance. Other societal issues include dysfunctional families, sexual abuse, physical abuse, domineering coaches and controlling relationships.
Psychological
The practice of an eating disorder can be viewed as a survival mechanism. Just as an alcoholic uses alcohol to cope, a person with an eating disorder like Anorexia, Bulimia or Compulsive Overeating can use eating, purging or restricting to deal with feelings and emotions that may otherwise seem overwhelming. Through the practice of the eating disorder, the individual may feel a sense of partial control over their seemingly uncontrollable life. Some of the underlying issues that are associated with an eating disorder include low self esteem, depression, feelings of loss of control, feelings of worthless, identity concerns, family communication problems and an inability to cope with emotions. The practice of an eating disorder may be an expression of something that the eating disordered individual has found no other way of expressing.
Through the interaction of the various components an eating disorder can be developed.