The exact cause of anorexia nervosa is unknown. As with many diseases, it's probably a combination of biological, psychological and environmental factors.

  • Biological. There may be genetic changes that make some people more vulnerable to developing anorexia. However, it's not clear specifically how your genes could cause anorexia. It may be that some people have a genetic tendency toward perfectionism, sensitivity and perseverance, all traits associated with anorexia. There's also some evidence that serotonin — one of the brain chemicals involved in depression — may play a role in anorexia.
  • Psychological. Some emotional characteristics may contribute to anorexia. Young women may have obsessive-compulsive personality traits that make it easier to stick to strict diets and forgo food despite being hungry. They may have an extreme drive for perfectionism, which means they may never think they're thin enough.
  • Environmental. Modern Western culture emphasizes thinness. The media are splashed with images of thin models and actors. Success and worth are often equated with being thin. Peer pressure may help fuel the desire to be thin, particularly among young girls.
Jan. 05, 2012