Anorexia Nervosa Diagnosis
An anorexia nervosa diagnosis will involve an analysis of the individual's physical signs and symptoms, along with their beliefs and behaviours.
A medical doctor will refer to a list of symptoms (or diagnostic criteria) to help them with making a diagnosis for anorexia nervosa.
Health professionals in the United States generally use diagnostic criteria from the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), while diagnostic criteria from The World Health Organisation's International Statistical Classification of Diseases and Related Health Problems (ICD-10) are most commonly used in Europe.
Diagnostic Criteria for Anorexia Nervosa
(Adapted from DSM-IV-TR)
A. Body weight is less than is considered normal for height and age. Weight is consistently less than 85% of that expected, which can be due to either weight loss, or failure to gain weight during growth.
B. Despite being underweight, there is an intense fear of putting on weight and becoming fat.
C. Refusal to accept low body weight as a problem, excessive influence of body weight and shape on self-worth, or a distorted body image perception.
D. Amenorrhea (abnormal absence of a minimum of three successive menstrual cycles).
There are two identifiable types of anorexia nervosa:
Restricting Type: Throughout the present episode of anorexia nervosa, there has been no regular occurrence of binge eating or purging (self-induced vomiting or the misuse of laxatives, diuretics, or enemas).
Binge Eating/Purging Type: Throughout the present episode of anorexia nervosa, there has been a regular occurrence of binge eating or purging.
Diagnostic Criteria for Anorexia Nervosa
(Adapted from ICD-10)
(a) Body weight is consistently 15% less (or lower) than that expected for height and age, or body mass index is 17.5 or less. This can be due to either weight loss, or failure to gain weight during growth.
(b) Weight loss is caused by the avoidance of foods perceived to be fattening, along with one or more of the following behaviours: self-induced vomiting, purging, excessive exercise, use of appetite suppressants and/or diuretics.
(c) Distorted body image perception driven by an intense, irrational fear of becoming fat, leads to the desire to remain at a low body weight.
(d) Amenorrhea (abnormal absence of a minimum of three successive menstrual cycles) in women, and loss of libido in men. There may be changes in growth hormone, cortisol, thyroid hormone and insulin.
(e) Puberty in girls and boys may be delayed if the onset of anorexia nervosa is prepubertal, but once recovery from the illness is made, it will often progress normally.
ICD-10 also includes 'atypical' anorexia nervosa, which refers to individuals who show some, but not all, of the characteristics of anorexia nervosa.
