Trastorno alimenticio

Journal of Child Psychology and Psychiatry 50:1-2 (2009), pp 163–169

doi:10.1111/j.1469-7610.2008.01983.x

Perplexities and provocations of eating disorders
Katherine A. Halmi
Weill Cornell Medical College, White Plains, NY, USA

Background: Etiological hypotheses of eating disorders, anorexia nervosa and bulimia nervosa have not produced informative research for predictably effectivetreatment. Methods: The rationale for applying a model of allostasis, a dysregulation of reward circuits with activation of brain and hormonal stress responses to maintain apparent stability, is developed for eating disorders. Results: The neurotransmitter systems involved in the allostatic state of a reward system in anorexia nervosa and bulimia nervosa may be similar to those present in drugaddiction. Conclusion: The biological vulnerabilities underlying the unique features of eating disorders should be intensively investigated with the advancing techniques in genetics and neuroimaging. Preventing chronicity with early diagnosis and adequate treatment before age 18 is necessary. Keywords: Anorexia nervosa, bulimia nervosa, allostasis, neurocircuitry.

The major eating disorders anorexianervosa and bulimia nervosa and variants thereof have been present in western civilization for the past two millennia. A well-preserved vomitorium is present in Herculaneum where Romans practiced the art of binge eating and purging. There are numerous accounts of women in the Middle Ages engaging in willful starvation in order to obtain sainthood. In the 13th century a detailed description of thelife of St. Margaret of Hungary reads as a typical life history of an anorexia nervosa patient (Halmi, 1994). Another notable example is St. Catherine of Siena whose biography in Latin detailed the type of reed she used to induce vomiting (Bell, 1985). Later in the 17th century descriptions of persons whose behavior resembled anorexia nervosa appeared in the British medical journals. Most notablewas that of an adolescent described by Morton (1689) and in the 18th century a description of several young women described by Sir William Gull (1888). It is unlikely any of the above described cases were starving themselves in order to be beautiful but rather fasting for a variety of different reasons. The common denominator in these cases is that severe food restriction spiraled out of control.Hypotheses concerning the development of eating disorders have not produced research with insightful answers leading to predictably effective treatment modalities. Despite massive amounts of correlational research it is still not possible to predict which type of patient will respond to what type of therapy. Nor is it possible to explain the mechanisms whereby therapy may be effective in aspecific case. This review will focus on the perplexities of researching the development of eating disorders and the provocations for developing effective treatment.
Conflict of interest statement: No conflicts declared.

Perplexities
In the current industrialized countries almost all women diet at some point in time during their lifetime, yet fewer than one-tenth of 1% of them will develop anorexianervosa and 1 to 3% will develop bulimia nervosa (Hoek, 1998). Most likely dieting does not spiral out of control in most women due to the physiological phenomenon of homeostasis which maintains stability in the internal milieu and allows an organism to survive (Sterling & Eyer, 1988). Homeostasis is a self-regulating process for multisystem coordination of an organism’s response to an acute challengeso that survival is possible (McEwen, 2000). In the conditions of anorexia nervosa and bulimia nervosa homeostasis fails, leading eventually to death or chronic impairment of functioning. Dysregulation of the brain reward system, a model proposed by Koob and LeMoal (1997) for understanding drug addiction, has salient features applicable to conceptualizing the development of eating disorders....