Anorexia Nervosa

Anorexia Nervosa is a serious psychiatric disorder involving persistent restriction of food intake, an intense fear of gaining weight, and a disturbance in how body weight or shape is experienced — often accompanied by a persistent lack of recognition of how serious the low body weight actually is. It carries the highest mortality rate of any psychiatric disorder, from both the medical complications of malnutrition and elevated suicide risk, which is why early, comprehensive treatment is critical rather than a 'wait and see' approach.

Anorexia Nervosa is defined by restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health; an intense fear of gaining weight or persistent behavior that interferes with weight gain, even at a significantly low weight; and a disturbance in the way body weight or shape is experienced, undue influence of weight or shape on self-evaluation, or a persistent lack of recognition of the seriousness of the current low body weight. It is specified as restricting type or binge-eating/purging type, with severity graded from mild to extreme.

Anorexia has one of the highest heritability estimates among psychiatric disorders, around 50–60%. It commonly arises in individuals with a perfectionistic or anxious temperament, often triggered by a period of dieting in a vulnerable person. Sociocultural pressures around thinness interact with this underlying biological vulnerability rather than acting as a sole cause. Importantly, prolonged restriction itself changes brain function in ways that help perpetuate the illness once established, which is part of why it can become so difficult to interrupt without structured treatment.

• Family history of eating disorders, depression, anxiety, or OCD
• A perfectionistic or anxious temperament
• History of dieting behavior
• Participation in activities emphasizing thinness or a specific body type — certain sports, dance, modeling
• Adolescence, a common period of onset
• History of trauma or significant life transitions
• Co-occurring anxiety or OCD

Research points to altered activity in brain reward circuits in response to food, with some studies suggesting a blunted dopamine reward response that reduces the motivation to eat despite hunger. Changes in the insula — a region involved in sensing internal bodily states like hunger — may contribute to distorted perception of hunger and body signals. Chronic starvation itself produces changes in brain structure and function, some reversible with weight restoration, that help perpetuate rigid, anxious thinking about food and can create a self-sustaining cycle.

• Persistent restriction of food intake leading to significantly low body weight for age, sex, and developmental context
• Intense fear of weight gain that doesn't diminish with weight loss
• Distorted body image or persistent denial of the seriousness of low body weight
• Preoccupation with food, calories, or body shape
• Rigid food rules or rituals
• Excessive exercise
• Social withdrawal, particularly around meals
• Physical signs of malnutrition: fatigue, dizziness, feeling cold, hair thinning, loss of menstrual periods, and in severe cases cardiac complications

• Restriction of energy intake leading to significantly low body weight for the person's context
• Intense fear of gaining weight, or persistent behavior interfering with weight gain, despite low weight
• Disturbance in the experience of body weight or shape, undue influence of weight/shape on self-worth, or lack of recognition of the seriousness of low weight
• Specified as restricting type or binge-eating/purging type
• Severity graded from mild to extreme based on body mass index in adults

Conditions a psychiatrist will consider and rule out before confirming this diagnosis:

Bulimia Nervosa

A binge-purge cycle is present, but body weight is typically within or above the normal range, unlike the significantly low weight required for anorexia.

Avoidant/Restrictive Food Intake Disorder (ARFID)

Food restriction occurs without the specific fear of weight gain or body image disturbance central to anorexia, driven instead by sensory sensitivity, low interest in eating, or fear of aversive consequences.

Medical causes of unintentional weight loss

Hyperthyroidism, malabsorption disorders, or malignancy should be ruled out or identified as co-occurring.

Major Depressive Disorder

Appetite and weight loss can occur, but without the specific fear of weight gain and body image disturbance central to anorexia.

• Comprehensive clinical and psychiatric interview
• Physical examination and vital signs, assessing for bradycardia, low blood pressure, and hypothermia — signs of the body's adaptation to starvation
• Weight and growth trajectory review, particularly important in adolescents against expected growth curves
• Laboratory tests: electrolytes, complete blood count, liver and kidney function, thyroid function
• ECG, given cardiac risk from electrolyte disturbance and a slowed heart rate
• Bone density assessment in cases of prolonged illness, given osteoporosis risk
• Menstrual history where relevant

A multidisciplinary team approach — psychiatry, medical monitoring, nutritional rehabilitation, and psychotherapy — is essential. Medical stabilization and weight restoration is often the necessary first priority, sometimes requiring hospitalization for careful, supervised refeeding given the risk of dangerous metabolic complications when nutrition is reintroduced too quickly after prolonged starvation. Family-Based Treatment has the strongest evidence for adolescents specifically.

No medication treats the core symptoms of anorexia itself

Medication may address co-occurring depression, anxiety, or OCD, though it is generally not effective as a primary treatment while significantly underweight, since starvation itself affects mood and often improves as weight is restored.

Family-Based Treatment (FBT / Maudsley approach)

The leading evidence-based treatment for adolescents, empowering parents to take an active role in supporting nutritional rehabilitation.

Cognitive Behavioral Therapy for Eating Disorders (CBT-E)

A leading approach for adults.

Specialist Supportive Clinical Management

Combines nutritional counseling with supportive psychotherapy.

Cognitive Remediation Therapy

Addresses the rigid thinking styles common in anorexia.

• Pursue nutritional rehabilitation under professional guidance rather than self-directed approaches, given the serious medical risks involved
• Work with a dietitian experienced in eating disorders
• Follow a gradual, medically supervised approach to normalizing eating patterns
• Build a support network and reduce exposure to diet culture or pro-eating-disorder content
• Address excessive exercise patterns under professional guidance

With early, comprehensive treatment — particularly Family-Based Treatment for adolescents — a substantial proportion of people achieve full recovery. The illness can become chronic in a subset of cases, and it carries the highest mortality rate of any psychiatric disorder, from both malnutrition-related medical complications and elevated suicide risk, making prompt, thorough treatment critical.

• Early identification and intervention, particularly in adolescents
• Media literacy and reduced exposure to idealized body image content during vulnerable developmental periods
• Avoiding excessive focus on weight or dieting in family and school environments
• Prompt professional evaluation of significant unexplained weight loss or preoccupation with weight/food, especially in at-risk individuals

For adolescents, Family-Based Treatment specifically empowers parents to take a direct, active role in supporting nutritional rehabilitation at home under professional guidance, rather than leaving the young person to manage eating independently during the acute illness. Avoid commenting on weight, shape, or specific foods in ways that could reinforce the disorder's preoccupations. Some families find it helpful to separate the illness from the person — treating the eating disorder as something distinct from your child, a common framing in FBT. Seek support for yourself given how demanding and frightening this illness can be for families, and treat any sign of medical instability — fainting, chest pain, severe weakness — as an emergency.

1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Text Revision (DSM-5-TR).
2. World Health Organization. International Classification of Diseases, 11th Revision (ICD-11).
3. National Institute for Health and Care Excellence (NICE). Eating disorders: recognition and treatment.
4. Academy for Eating Disorders.