Psychiatric Undereating Disorders

Overview of Disorders of Negative Energy Balance

• Disorders characterized by limited food intake include anorexia nervosa and avoidant restrictive food intake disorder (ARFID).
• Underweight individuals face high risks comparable to obesity, with severe health hazards associated with low BMI.

Anorexia Nervosa

• Recognized as the deadliest psychiatric illness with a 20% death rate within 20 years.
• Physical causes of death are five times more likely than expected for the patient demographic.
• Suicide risk is significantly elevated, being 32 times more prevalent than in the general population.
• Lifetime prevalence rates are 0.9% in women and 0.3% in men.
• Diagnostic criteria include significant restriction of energy intake leading to a low body weight relative to age, sex, and health.

Avoidant Restrictive Food Intake Disorder (ARFID)

• Distinguished from anorexia nervosa by the absence of body image disturbance.
• Often co-occurs with conditions like autism and ADHD; severity surpasses that of primary disorders.
• Associated with heightened fear responses to unfamiliar foods, perceived as terrifying.
• Preferred foods are typically predictable and heavily processed.

Treatment Approaches for ARFID

• Younger children may benefit from creative engagement with food, such as "messy food picnics," fostering a safe environment.
• Older patients often receive cognitive behavioral therapy (CBT) to address food-related fears.

Cognitive and Behavioral Symptoms of Anorexia Nervosa

• Perfectionism, rigid thinking, and a strong focus on details are common traits.
• Significant overlap occurs with anxiety disorders, obsessive-compulsive disorders, and autism spectrum disorders.

Hormonal and Physiological Changes in Anorexia Nervosa

• Patients exhibit a profile of low leptin and insulin, and high ghrelin levels due to prolonged starvation.
• Chronic starvation leads to continuous stress responses, indicated by elevated cortisol levels and an overactive sympathetic nervous system.
• Dysregulated cytokine levels, particularly pro-inflammatory cytokines (IL-1 beta, IL-6, TNF alpha), indicate an inflammatory state inconsistent with typical malnutrition responses.
• Physiological effects include amenorrhea, loss of fertility, and altered bone marrow morphology resulting in anemia.

Cognitive Flexibility in Anorexia Nervosa

• Cognitive flexibility refers to adapting behavior based on changing circumstances; flexibility is often reduced in anorexia nervosa.
• Cognitive inflexibility is linked to fixation on restrictive eating patterns and specific foods.
• Improvements in cognitive flexibility may correlate with symptom relief.
• Cognitive inflexibility may exist pre-morbidly, suggesting a genetic predisposition.

Therapeutic Innovations

• Psychotherapy is a standard treatment, with emerging research into the use of psychedelic drugs (e.g., psilocybin, DMT, LSD) showing promise in enhancing cognitive flexibility.

Cachexia

• This condition occurs as a secondary illness related to chronic diseases like cancer and heart failure.
• It involves a significant energy balance disturbance, marked by reduced appetite and increased metabolic demands.
• Defined as a multifactorial syndrome characterized by the ongoing loss of skeletal muscle mass that cannot be reversed with nutritional support.
• Clinical criteria include weight loss exceeding 5%, or at least 2% in those already exhibiting weight depletion based on BMI metrics.

Explore the complexities of psychiatric undereating disorders in this quiz. Focus on Anorexia Nervosa and Avoidant Restrictive Food Intake Disorder (ARFID) and their implications on health. Understand how these disorders relate to overall energy balance and the impact on metabolism.