What are the diagnostic criteria for anorexia nervosa binge subtype?

Diagnostic Criteria for Anorexia Nervosa Binge-Eating/Purging Subtype

According to the DSM-5, anorexia nervosa binge-eating/purging subtype is characterized by restriction of food intake leading to significantly low body weight, along with binge eating and/or purging behaviors, while maintaining the core features of intense fear of weight gain and body image distortion.

Core Diagnostic Criteria

The diagnostic criteria for anorexia nervosa binge-eating/purging subtype includes:

• Restriction of food intake leading to significantly lower than expected body weight 1
• Intense fear of gaining weight or becoming fat 1
• Body image distortion 1
• Engagement in binge eating and/or purging behaviors 1

Specific Features of the Binge-Eating/Purging Subtype

The binge-eating/purging subtype is distinguished from the restricting subtype by:

• Recurrent episodes of binge eating, characterized by:

  • Consuming a larger amount of food within a discrete time period (e.g., 2 hours) compared to what most people would eat in similar circumstances 1
  • A sense of lack of control over eating during these episodes 1, 2

• And/or purging behaviors such as:

  • Self-induced vomiting 1, 3
  • Misuse of laxatives, diuretics, or other medications 1, 3
  • Periods of starvation 1
  • Excessive exercise 1

Clinical Significance

• The binge-eating/purging subtype of anorexia nervosa represents a distinct clinical presentation with important implications for treatment and prognosis 3
• Research indicates that anorexia nervosa patients who purge, regardless of whether they report objective binge episodes, display significantly more psychopathology than those who only restrict 3
• The profile of psychological disturbance in anorexia nervosa patients who purge is similar to those who both binge and purge 3

Important Distinctions

• Unlike bulimia nervosa, individuals with anorexia nervosa binge-eating/purging subtype maintain a significantly low body weight 1
• Unlike binge eating disorder, compensatory behaviors are present in anorexia nervosa binge-eating/purging subtype 1, 2
• The medical risks associated with purging behaviors make this distinction clinically important 3

Medical Complications

• Young people with anorexia nervosa who have lost large amounts of weight or lost weight too rapidly can develop serious health issues including:
  • Hypothermia 1
  • Bradycardia 1
  • Hypotension 1
  • Other serious medical complications 1

Prevalence and Demographics

• Anorexia nervosa has a lifetime prevalence of approximately 0.3% in adolescent females 1
• The female-to-male ratio is approximately 9:1, though increasing numbers of males with eating disorders are being recognized 1
• The peak age of onset for anorexia nervosa is early to mid-adolescence 1

Clinical Implications

• The distinction between restricting and binge-eating/purging subtypes is important for treatment planning and prognosis 3
• The presence of purging behaviors, regardless of whether objective binge episodes occur, may be more clinically meaningful for subtyping anorexia nervosa than the presence of binge eating alone 3
• Early identification and treatment are critical as mortality rates for eating disorders are among the highest for any psychiatric disorder 1