What is the most common psychiatric comorbidity associated with anorexia nervosa?

Most Common Psychiatric Comorbidity in Anorexia Nervosa

Depression is the most common psychiatric comorbidity associated with anorexia nervosa, followed closely by anxiety disorders, particularly social anxiety disorder.

Prevalence of Psychiatric Comorbidities in Anorexia Nervosa

Psychiatric comorbidities are extremely common in patients with anorexia nervosa, with approximately 70% of patients meeting criteria for at least one additional psychiatric diagnosis 1. The evidence reveals a clear pattern of comorbidity:

• Major depressive disorder: Affects approximately 41.7% of adolescents with anorexia nervosa 2, making it one of the most prevalent comorbidities
• Social anxiety disorder: Present in 52.8% of adolescents with anorexia nervosa 2, particularly high in younger populations
• Generalized anxiety disorder: Found in approximately 19.4% of patients 2
• Obsessive-compulsive disorder (OCD): Significantly more frequent in anorexia nervosa than in bulimia nervosa 3

Depression and Anorexia Nervosa

Depression and anorexia nervosa share a complex bidirectional relationship:

• Malnutrition and starvation directly affect neurotransmitter systems involved in mood regulation
• The psychological distress of body image disturbance contributes to depressive symptoms
• Depression can exacerbate anorexic behaviors through decreased motivation for recovery
• Mean depression scores on standardized measures (Children Depression Inventory) are elevated at 15.5 (SD: 10.7) 2

Anxiety Disorders and Anorexia Nervosa

Anxiety disorders frequently co-occur with anorexia nervosa:

• Social anxiety disorder: Particularly common, with mean scores on the Liebowitz Social Anxiety Scale of 34.8 (SD: 28.3) 2
• OCD: Shows specific association with anorexia compared to other eating disorders 3
• Agoraphobia: Also more frequent in anorexia than bulimia 3

Clinical Implications

The high comorbidity rate has significant implications for treatment:

1. Assessment: Comprehensive psychiatric evaluation is essential for all anorexia nervosa patients
2. Treatment planning: Must address both the eating disorder and comorbid conditions
3. Medication response: Underweight patients with anorexia nervosa often show poor response to psychopharmacologic treatments until nutrition is restored 4
4. Mortality risk: Comorbid depression significantly increases suicide risk, with approximately 11-44% of young people with body dysmorphic disorder (which shares features with anorexia) having attempted suicide 1

Treatment Considerations

When treating comorbid depression and anxiety in anorexia nervosa:

• Prioritize nutritional rehabilitation: Malnutrition directly affects brain function and medication response
• Address psychological aspects: Focus on normalizing eating behaviors, restoring weight, and addressing psychological aspects like fear of weight gain and body image disturbance 5
• Family-based treatment: Recommended for adolescents with anorexia nervosa 5
• Monitor for suicidality: Given the elevated suicide risk in this population

Common Pitfalls to Avoid

1. Misattribution of symptoms: Starvation itself can cause symptoms that mimic depression and anxiety
2. Premature medication: Expecting antidepressants to work effectively before nutritional status is improved
3. Overlooking comorbidity: Focusing solely on weight restoration without addressing psychiatric comorbidities
4. Diagnostic confusion: Mistaking the body image disturbance of anorexia for body dysmorphic disorder

The evidence clearly demonstrates that depression and anxiety disorders, particularly social anxiety disorder, are the most prevalent psychiatric comorbidities in anorexia nervosa. Addressing these comorbidities is essential for comprehensive treatment and improved outcomes.