Definitions
Anorexia Nervosia(AN) a serious mental illness characterized by:(1)
· Extreme fear of gaining weight
· Abnormally low body weight
· Distorted perception of body shape and weight
· Amenorrhea
Differentiating Eating Disorders
AN, bulimia nervosa (BN) and eating disorders not otherwise specified are the eating disorders classified by the "American Psychiatric Association's Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR)" (1,2). For a good description of AN and BM, refer to the DSM-IV-TR diagnostic criteria of each of these eating disorders, described in tables 1 and 2. Patients can switch between two subtypes of AN, restricting and binge eating/purging, which are described in table 1. In addition, there are two subtypes of BN, purging and non-purging, which are described in table 2. (2,3)
In about 30% to 64% of individuals with eating disorders, BN and AN occur together and may be a continuum of symptoms rather than diagnostic entities.(4) Patients may alternate from AN to BN or visa versa8. Moreover, AN and BN are related disorders and have some similar features. (2,4) For example, patients with either BM or AN have a distorted body image. Additionally, binge-eating and purging behaviour can occur in both the purging type of BN and the binge-eating/purging type of AN. A unique feature of anorexia nervosa is a body weight of less than 85% of what is considered normal for the patient's height and age. On the other hand, most patients with BN have a normal body weight. If patients with BN are underweight it is only by a small amount. Refer to figure 1 for more unique and similar features of AN and BN. (2-4)
If an individual meets most of the DSM-IV-TR criteria for AN and BN but not all, they are classified as having eating disorder not otherwise specified (EDNOS) by the American Psychiatric Association (e.g. binge eating disorder, night eating syndrome). (2) Recurrent episodes of binging occur in patients with binge eating disorder; however, these patients do not display compensatory behaviours. For a definition of binge eating refer to criterion A from table 2. For a diagnosis of binge eating disorder to be made, binging needs to occur at least two times a week over a 6 month period. (2) Night eating syndrome occurs when individuals limit the amount of food they eat during the day and eat at night in order to compensate. (5)
· Extreme fear of gaining weight
· Abnormally low body weight
· Distorted perception of body shape and weight
· Amenorrhea
Differentiating Eating Disorders
AN, bulimia nervosa (BN) and eating disorders not otherwise specified are the eating disorders classified by the "American Psychiatric Association's Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR)" (1,2). For a good description of AN and BM, refer to the DSM-IV-TR diagnostic criteria of each of these eating disorders, described in tables 1 and 2. Patients can switch between two subtypes of AN, restricting and binge eating/purging, which are described in table 1. In addition, there are two subtypes of BN, purging and non-purging, which are described in table 2. (2,3)
In about 30% to 64% of individuals with eating disorders, BN and AN occur together and may be a continuum of symptoms rather than diagnostic entities.(4) Patients may alternate from AN to BN or visa versa8. Moreover, AN and BN are related disorders and have some similar features. (2,4) For example, patients with either BM or AN have a distorted body image. Additionally, binge-eating and purging behaviour can occur in both the purging type of BN and the binge-eating/purging type of AN. A unique feature of anorexia nervosa is a body weight of less than 85% of what is considered normal for the patient's height and age. On the other hand, most patients with BN have a normal body weight. If patients with BN are underweight it is only by a small amount. Refer to figure 1 for more unique and similar features of AN and BN. (2-4)
If an individual meets most of the DSM-IV-TR criteria for AN and BN but not all, they are classified as having eating disorder not otherwise specified (EDNOS) by the American Psychiatric Association (e.g. binge eating disorder, night eating syndrome). (2) Recurrent episodes of binging occur in patients with binge eating disorder; however, these patients do not display compensatory behaviours. For a definition of binge eating refer to criterion A from table 2. For a diagnosis of binge eating disorder to be made, binging needs to occur at least two times a week over a 6 month period. (2) Night eating syndrome occurs when individuals limit the amount of food they eat during the day and eat at night in order to compensate. (5)
Table 1."DSM-IV-R Diagnostic Criteria for Anorexia Nervosa"(2)
Table 2. "DSM-IV-R Diagnostic Criteria for Bulimia Nervosa" (2)
Figure 1- Unique and Similar Signs and Symptoms of BM and AN (4)
References
1. Klein D. Attia E. Anorexia nervosa in adults: Diagnosis, associated clinical features, and assessment. UpToDate. http://www.uptodate.com/contents/anorexia-nervosa-in-adults-diagnosis-associated-clinical-features-and-assessment. Updated February 29, 2012. Accessed June 1, 2013.
2. Treatment of patients with eating disorders,third edition. American Psychiatric Association. American Psychiatric Association. Am J Psychiatry. 2006;163(7 Suppl):4-54.
3. Aigner M, Treasure J, Kaye W, et al. World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Pharmacological Treatment of Eating Disorders. World J Biol Psychiatry. 2011;12(6):400-43.
4. Talbert RL, DiPiro JT, Matzke GR, Posey LM, Wells BG, Yee GC. Chapter 64. Multiple Sclerosis. In: Pharmacotherapy: A Pathophysiologic Approach. 8th ed. New York: McGraw-Hill; 2011. http://www.accesspharmacy.com/content.aspx?aID=7984977. Accessed June 1, 2013.
5. Information on eating disorders and weight preoccupation. nedic. http://www.nedic.ca/knowthefacts/definitions.shtml. Accessed June 1, 2013.
1. Klein D. Attia E. Anorexia nervosa in adults: Diagnosis, associated clinical features, and assessment. UpToDate. http://www.uptodate.com/contents/anorexia-nervosa-in-adults-diagnosis-associated-clinical-features-and-assessment. Updated February 29, 2012. Accessed June 1, 2013.
2. Treatment of patients with eating disorders,third edition. American Psychiatric Association. American Psychiatric Association. Am J Psychiatry. 2006;163(7 Suppl):4-54.
3. Aigner M, Treasure J, Kaye W, et al. World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Pharmacological Treatment of Eating Disorders. World J Biol Psychiatry. 2011;12(6):400-43.
4. Talbert RL, DiPiro JT, Matzke GR, Posey LM, Wells BG, Yee GC. Chapter 64. Multiple Sclerosis. In: Pharmacotherapy: A Pathophysiologic Approach. 8th ed. New York: McGraw-Hill; 2011. http://www.accesspharmacy.com/content.aspx?aID=7984977. Accessed June 1, 2013.
5. Information on eating disorders and weight preoccupation. nedic. http://www.nedic.ca/knowthefacts/definitions.shtml. Accessed June 1, 2013.