Anorexia nervosa is an eating disorder marked by an intense fear of weight gain, distorted body image, and extreme dieting and exercise, which lead to severe caloric restriction. It typically begins in the preteen or young adult years, is more common in women, and can result in life-threatening malnutrition if untreated.

The main signs and symptoms of anorexia nervosa include intense fear of weight gain, distorted body image, restrictive eating behaviors, and physical manifestations such as being underweight and sensitivity to cold. Complications can arise, including serious health issues like heart problems, kidney damage, and seizures.

Anorexia nervosa is diagnosed based on criteria from the DSM-5, which includes being significantly underweight, having an intense fear of weight gain, and possessing a distorted body image. Additionally, individuals may need to consult both a medical doctor and a mental health professional to confirm the diagnosis and rule out other causes of physical symptoms.

The main medical treatments for anorexia nervosa focus on improving caloric intake and may involve a team of healthcare professionals to prevent complications like refeeding syndrome. Although medications can help with underlying mental health issues, therapy is essential to address the fears and beliefs that drive disordered eating behaviors.

Some studies have investigated cannabinoids for treating anorexia nervosa, and only the synthetic cannabinoid dronabinol resulted in minimal weight gain, whereas other substances had negative effects. Overall, the current evidence does not support the use of cannabinoids for this condition.

Medically supervised diets are crucial in treating anorexia nervosa, especially for individuals who are severely malnourished because they may require tube or intravenous feeding to avoid electrolyte imbalances. However, with proper supervision, some individuals may safely increase food intake rapidly after a period of starvation.

Deep brain stimulation has shown promise in improving psychiatric symptoms and weight restoration in anorexia nervosa, but further studies are needed due to limited participant numbers. Additionally, although intranasal oxytocin appears to be ineffective, social support and mindfulness practices may help alleviate some psychological symptoms.

Anorexia nervosa may develop due to a combination of genetic, hormonal, and brain structure factors, along with psychological traits like perfectionism and mood disorders. Additionally, experiences such as bullying, abuse, childhood eating issues, and the influence of social media and beauty ideals can increase the risk.