Diagnosis of Eating Disorder Symptoms

The patient presents with a combination of symptoms that require careful diagnostic evaluation:

• Abnormally low body weight.
• Recurrent binge eating and purging (5-10 times/week for years).
• Intense fear of weight gain and distorted body image (feeling fat despite low weight).
• Amenorrhea.

Evaluating Diagnostic Criteria

Let's analyze the symptoms against the criteria for the given options:

Anorexia Nervosa

Key diagnostic features include:

• Restriction of energy intake leading to significantly low body weight. (Present)
• Intense fear of gaining weight or persistent behavior to prevent weight gain. (Present)
• Disturbance in self-perception of body weight or shape. (Present)

The patient's low body weight, alongside binge-purging behaviors and fear of fatness, fits the criteria for Anorexia Nervosa, potentially the binge-eating/purging subtype.

Bulimia Nervosa

Key diagnostic features include:

• Recurrent episodes of binge eating. (Present)
• Recurrent inappropriate compensatory behavior (purging). (Present)
• Self-evaluation is unduly influenced by body shape and weight. (Present)
• Crucially, the episodes occur at normal weight or overweight. (Absent - Patient is underweight)

The significantly low body weight rules out Bulimia Nervosa as the primary diagnosis.

Other Options

• Endogenous Depression: While depression can co-occur, the primary symptoms described (low weight, fear of fatness, bingeing/purging) are characteristic of an eating disorder, not primarily depression.
• Schizophrenia: This is a psychotic disorder with symptoms like hallucinations and delusions. While unusual eating patterns can occur, the specific symptom cluster points strongly towards an eating disorder.

Conclusion

Given the presence of significantly low body weight combined with binge eating, purging, intense fear of fatness, distorted body image, and amenorrhea, the most appropriate diagnosis is Anorexia nervosa.