What is anorexia nervosa and its treatment?

Anorexia Nervosa and Refeeding Syndrome: Diagnosis and Treatment

Anorexia nervosa is a severe psychiatric disorder requiring immediate medical and psychological treatment due to its high mortality rate among psychiatric disorders, characterized by refusal to maintain minimally normal body weight and severe disturbances in eating behavior.

Definition and Characteristics of Anorexia Nervosa

• Anorexia nervosa is a psychological disorder characterized by a refusal to maintain a minimally normal body weight, severe disturbances in eating behavior, and an intense fear of weight gain 1
• The disorder typically begins in adolescence during the peripubertal period and affects predominantly females (>90% of cases) 1, 2
• Prevalence is approximately 0.3% among women, with increasing incidence in recent decades 1, 3
• Without early effective treatment, anorexia has a protracted course with significant physical, psychological, and social morbidity 2

Clinical Presentation and Diagnosis

• Initial evaluation should establish diagnosis, determine illness severity, evaluate medical and nutritional status, and perform psychosocial assessment 1
• Key diagnostic features include:
  • Refusal to maintain minimally normal body weight
  • Intense fear of gaining weight despite being underweight
  • Disturbance in body image perception
  • Amenorrhea in females (though no longer required in current diagnostic criteria) 1
• More than half of children and adolescents with eating disorders may not fully meet all diagnostic criteria but still experience the same medical and psychological consequences 1

Medical Assessment

• The American Psychiatric Association recommends comprehensive initial evaluation including:
  • Weighing the patient and quantifying eating/weight control behaviors 1
  • Identifying co-occurring health conditions and psychiatric disorders 1
  • Comprehensive review of systems 1
  • Physical examination assessing vital signs (including orthostatic measurements), height, weight, BMI, and signs of malnutrition or purging 1
  • Laboratory assessment including complete blood count, comprehensive metabolic panel, electrolytes, liver enzymes, and renal function tests 1
  • Electrocardiogram for patients with restrictive eating disorders, severe purging, or those taking medications that prolong QTc intervals 1

Refeeding Syndrome

• Refeeding syndrome is a potentially fatal complication that can occur during nutritional rehabilitation of severely malnourished patients with anorexia nervosa 4
• It is characterized by fluid and electrolyte shifts, particularly hypophosphatemia, hypokalemia, and hypomagnesemia, which can lead to cardiac arrhythmias, seizures, and death 5
• Risk factors include severe malnutrition, rapid refeeding, and electrolyte abnormalities prior to refeeding 4

Treatment Approach

Medical Stabilization and Nutritional Rehabilitation

• Medical stabilization and nutritional rehabilitation are the most crucial determinants of short and intermediate-term outcomes 1
• For patients with anorexia nervosa requiring nutritional rehabilitation and weight restoration, individualized goals should be set for weekly weight gain and target weight 1
• For growing children and adolescents, goal weight should be reevaluated at three to six-month intervals based on changing age and height 1

Psychotherapeutic Interventions

• For adults with anorexia nervosa, the APA recommends eating disorder-focused psychotherapy that includes normalizing eating behaviors, restoring weight, and addressing psychological aspects like fear of weight gain and body image disturbance 1
• For adolescents and emerging adults with involved caregivers, eating disorder-focused family-based treatment is recommended 1
• Family therapy may be more effective than individual therapy in younger patients who have been ill for less than 3 years 3
• Technology-based interventions (TBIs) are emerging as promising approaches, especially guided computer-based interventions and videoconferencing 1

Pharmacological Treatment

• Evidence for medication in anorexia nervosa is limited 6, 3
• Some evidence suggests fluoxetine may help prevent relapse in weight-restored patients 3
• Unlike bulimia nervosa, where serotonin reuptake inhibitors (e.g., fluoxetine 60mg daily) are recommended, there are no specific medication recommendations for the acute treatment of anorexia nervosa 1

Special Considerations

Severe and Enduring Anorexia Nervosa (SE-AN)

• Some individuals develop a very long-standing form of illness requiring different treatment interventions over time 5
• Treatment approaches for SE-AN may focus more on quality of life, medical stability, and health-promoting meal plans rather than complete weight restoration 5, 6

Complications

• Anorexia nervosa can affect nearly every organ system in the body 3
• Cardiac complications are responsible for approximately 50% of deaths 3
• Long-term complications include osteopenia and increased fracture risk 3
• Brain studies suggest gray matter volume deficits may persist after refeeding 3

Prevention and Early Intervention

• Early identification and intervention are crucial as they can prevent progression to more severe illness 1, 4
• Prevention programs aim to moderate the overvaluation of thinness and body dissatisfaction 2
• Involving family support early in the course of illness can produce sustained changes 2

Multidisciplinary Care

• A comprehensive, culturally appropriate, and person-centered treatment plan incorporating medical, psychiatric, psychological, and nutritional expertise via a coordinated multidisciplinary team is recommended 1
• For chronic anorexia nervosa, an interdisciplinary team of medical professionals is essential 4