Can Eating Disorders Impact Bipolar Disorder?
Yes, eating disorders significantly worsen the clinical course and severity of bipolar disorder in adolescents and young adults, with comorbidity rates reaching 28-36% and associated with increased depression severity, suicidality, self-harm, and overall functional impairment.
Prevalence and Clinical Significance
The co-occurrence of eating disorders and bipolar disorder is substantial and clinically meaningful:
- Eating disorders affect 28-36% of youth with bipolar disorder, representing a major comorbidity that cannot be overlooked 1, 2.
- Bipolar II disorder shows particularly high rates of eating disorder comorbidity (20.6%) compared to Bipolar I (12.4%), suggesting specific vulnerability in the bipolar spectrum 3.
- Bulimia nervosa and binge eating disorder show the strongest associations with bipolar disorder, especially with hypomanic features and Bipolar II presentations 4, 5.
Impact on Disease Severity and Outcomes
When eating disorders co-occur with bipolar disorder, the clinical picture becomes substantially more severe:
Mood and Suicidality
- Depression severity is significantly higher in bipolar youth with comorbid eating disorders (depression rating scores 40.5 vs 34.5, effect size 0.59) 2.
- Suicide attempts and suicidal ideation are markedly elevated in the comorbid group 1.
- Non-suicidal self-injury rates are substantially increased when eating disorders complicate bipolar disorder 1.
Comorbidity Burden
- Anxiety disorders, PTSD, and substance use disorders cluster together with the eating disorder-bipolar combination, creating a complex clinical presentation 1.
- Affective lability and borderline personality traits are significantly more severe in bipolar patients with comorbid eating disorders 3, 1.
- History of sexual abuse and childhood trauma is more common, particularly in those with binge eating disorder 3, 1.
Demographic Patterns
- Female sex is the strongest predictor of eating disorder comorbidity in bipolar disorder (odds ratio 3.8-4.61) 3, 1.
- Cigarette smoking is significantly associated with the comorbid presentation 1.
Clinical Implications for Assessment
When evaluating adolescents and young adults with bipolar disorder, clinicians must systematically screen for:
- Eating disorder cognitions (present in 74% of comorbid cases), including preoccupation with weight, body image distortion, and fear of weight gain 2.
- Binge eating behaviors (40% of comorbid cases) 2.
- Purging behaviors (25% of comorbid cases) including self-induced vomiting and laxative abuse 2.
- Restricting behaviors (17% of comorbid cases) 2.
Important caveat: Eating disorder symptoms in bipolar disorder may be episodic and mood-state dependent, requiring assessment across different phases of illness 4.
Treatment Considerations
The American Academy of Child and Adolescent Psychiatry emphasizes that mood stabilization must be the primary treatment target, as manic and hypomanic episodes can drive impulsive eating behaviors 6.
Pharmacological Approach
- Lithium and topiramate show efficacy for both conditions, making them rational first-line choices when treating comorbid presentations 5.
- Mood stabilizers and atypical antipsychotics should be prioritized to control mood episodes that may exacerbate eating pathology 6.
- Avoid unnecessary polypharmacy while ensuring adequate coverage for both mood and behavioral symptoms 6.
Psychosocial Interventions
- Cognitive-behavioral therapy targeting both mood and eating behaviors should be implemented concurrently 6.
- Dialectical behavioral therapy is particularly useful for patients with mood dysregulation and problematic eating behaviors 6.
- Psychoeducation for patient and family regarding the relationship between mood episodes and eating symptoms is essential 6.
Shared Pathophysiology
The overlap between these disorders extends beyond simple comorbidity:
- Dysregulation across multiple domains including mood, eating, impulsivity, and compulsivity suggests shared underlying mechanisms 4.
- Family history of affective disorders is elevated in the comorbid group, suggesting genetic vulnerability 1.
- The phenomenologic similarities are most apparent when examining spectrum rather than full-threshold presentations 4.
Monitoring Requirements
- Regular assessment of both mood symptoms and eating behaviors is mandatory throughout treatment 6.
- Suicide risk assessment must be ongoing, given the significantly elevated risk in this population 6, 1.
- Laboratory monitoring based on specific medications (lithium levels, liver function) is essential 6.
Critical pitfall to avoid: Do not dismiss eating disorder symptoms as simply mood-driven behaviors that will resolve with mood stabilization alone. The comorbidity requires targeted assessment and treatment of both conditions simultaneously 4, 5.