Why Eating Disorders and Substance Abuse So Commonly Co-Occur

A significant percentage of those with eating disorders also struggle with alcohol and substance use disorders. In 2003, the National Center on Addiction and Substance Abuse issued the seminal report, “Food for Thought: Substance Use and Eating Disorders,” which highlights this relationship. (1) The report found that:

Individuals with eating disorders were up to 5 times as likely as those without eating disorders to abuse alcohol or illicit drugs, and those who abused alcohol or illicit drugs were up to 11 times as likely as those who did not to have had eating disorders. Specifically, up to 50% of individuals with eating disorders abused alcohol or illicit drugs, compared to 9% of the general population. Conversely, up to 35% of individuals who abused or were dependent on alcohol or other drugs have had eating disorders, compared to 3% of the general population.

Other research has offered similar findings. Struggling with an eating disorder ­ or a substance use disorder ­increases one’s chances of developing the other disorder.

It appears that the most highly correlated eating disorder with substance misuse is Bulimia Nervosa (BN). A 2007 large­scale study found that those with BN had a higher lifetime comorbidity estimate of substance use disorders (SUD) than those with Anorexia Nervosa (AN) or Binge Eating Disorder (BED). (2)

A more recent study documented a similar finding, with patients with BN using alcohol/other substances more commonly than those diagnosed with AN­R (Restricting Type), BED, or Eating Disorder Not Otherwise Specified (now called Other Specified Eating and Feeding Disorder). This study also found that patients with AN­BP (Binge Eating/Purging Type) used alcohol/substances with greater frequency than those with AN­R and that participants’ frequency of binge eating and purging varied with the frequency of their substance use. (3)

Why might eating and substance use disorders so commonly co­occur? Let’s take a look at some possible explanations:

Common genetic underpinnings: We know that both eating disorders and substance use disorders have significant genetic components. Is it possible that the same genes are responsible for both disorders? One study suggests so. A 2013 twin study found significant genetic correlations between alcohol dependence and, in this case, binge eating, as well as between alcohol dependence and the use of compensatory behaviors (e.g., purging, use of laxatives/diuretics). The authors concluded that alcohol dependence and the tendency to engage in binge eating and compensatory behaviors are influenced by common genetic factors. (4)

Common psychological factors: Psychology and behavior are influenced by genes, biology and the environment. Those who struggle with eating disorders and alcohol/substance problems often have difficulty managing emotions and/or trouble with impulse control – both disorders may reflect these challenges. Symptoms of these disorders may serve a similar function in helping individuals self­medicate anxiety, trauma, depression, etc.

Some substances are used specifically in the service of an eating disorder. Many patients report using substances to aid in restriction, bingeing, and purging. Even if unintentional, the frequent use of alcohol/drugs can lead to eating disorder symptoms, which, if unchecked, can spiral into disorder.

Using substances to cope with eating disorders symptoms: When asked to discuss the relationship between their eating disorders and alcohol/drug misuse, patients typically comment on the use of alcohol/drugs as a mechanism to “quiet” their eating disorders, particularly body image distress. What begins as a (maladaptive) coping strategy becomes its own disorder.

Symptom substitution: Many patients report that as they try to reduce their reliance on eating disorder symptoms (or alcohol/drugs), symptoms of the other disorder increase. We often discuss this as the “Whac­A­Mole” phenomenon ­ take away one behavior, and another develops/strengthens in its place. Symptom substitution highlights the importance of addressing both disorders simultaneously.

Some of the same approaches can be used to treat eating disorders and substance use disorders. These include CBT, DBT, family therapy, motivational interviewing and targeting other co­-occurring conditions, including mood disorders, anxiety, trauma, self ­injury, etc. When eating disorders and substance use disorders co-­occur, it is crucial that they be addressed in tandem to prevent symptom substitution or symptoms of one disorder triggering the other. Further, even moderate use of alcohol/drugs might impact those in eating disorder recovery, with many substances interfering with hunger/fullness cues and impacting judgment, impulsivity and emotion regulation. Patients with eating disorders who do not have co-­occurring substance use disorders might still opt for a period of alcohol/drug abstinence until they are more stable in their eating disorder recovery.

1 http://www.centeronaddiction.org/addiction­research/reports/food­thought­substance­abuse­and­eating­disorders

2 http://www.ncbi.nlm.nih.gov/pubmed/16815322

3 http://onlinelibrary.wiley.com/doi/10.1002/erv.2410/abstract?userIsAuthenticated=true&deniedAccessCustomised Message=

4 http://www.ncbi.nlm.nih.gov/pubmed/23948525