Co-Occurring Disorders Editor · Last reviewed January 2025
The co-occurrence of eating disorders and substance use disorders is one of the most clinically significant presentations in behavioral health treatment. Understanding how these two conditions interact, which came first, and how integrated treatment addresses both simultaneously is essential for effective care.
Prevalence and the Bidirectional Relationship
Eating disorders and substance use disorders co-occur at higher-than-chance rates. Alcohol use disorder is most commonly co-occurring with bulimia nervosa and binge eating disorder; stimulant use is disproportionately represented in anorexia nervosa, used for appetite suppression. Research has found that 16–26% of individuals with bulimia nervosa have co-occurring alcohol use disorder. Shared mechanisms include reward system dysregulation, impulsivity, trauma histories, and affective dysregulation — the same features that characterize many co-occurring presentations. The relationship is bidirectional and mutually reinforcing: mental health symptoms drive substance use as self-medication, and substance use worsens, triggers, or maintains mental health symptoms through direct neurobiological effects and disruption of sleep, social functioning, and daily routines.
Diagnostic Complexity
Accurately diagnosing both conditions in the context of active substance use is challenging. Many substances produce psychiatric symptoms during intoxication or withdrawal that mimic primary mental health conditions. Comprehensive dual diagnosis assessment by a clinician trained in both areas — ideally after a period of sobriety or stable use — is essential. That said, severe psychiatric symptoms may require immediate treatment regardless of substance use status.
Why Sequential Treatment Often Fails
When mental health symptoms are driving substance use as self-medication, leaving those symptoms untreated undermines sobriety. When substance use is maintaining psychiatric symptoms through neurobiological dysregulation or psychological avoidance, leaving addiction untreated undermines psychiatric treatment. Integrated simultaneous treatment consistently outperforms sequential approaches in the research literature.
Integrated Treatment
Integrated treatment for eating disorders and SUD requires specialized expertise in both conditions — a combination that is relatively rare. Medical monitoring is frequently required given the physical complications of both eating disorders (electrolyte imbalances, cardiac arrhythmias) and SUD (withdrawal, hepatic effects of alcohol). For anorexia, weight restoration must generally precede intensive trauma or addiction work — psychotherapy is less effective in severely malnourished states. CBT addressing both eating disorder cognitions and substance use patterns has strong theoretical and clinical appeal. DBT has evidence for BPD-related eating disorder presentations and specifically for binge eating disorder. Lisdexamfetamine (Vyvanse), FDA-approved for moderate-to-severe BED, requires careful clinical judgment in individuals with stimulant use histories.
Finding Integrated Treatment
SAMHSA's National Helpline (1-800-662-4357) and treatment locator at findtreatment.gov identify programs with dual diagnosis specialty. When evaluating programs, ask specifically whether both conditions are treated simultaneously, whether a psychiatric prescriber is on staff, and what evidence-based co-occurring disorders treatments are used.
Related: Eating Disorders Overview · DBT for Co-Occurring Disorders · Trauma-Informed Care