Pills for bites: the alarming link between drug abuse and eating disorders

This is a guest post for ScienceofEDs blog. If you're interested in research relating to eating disorders, ScienceofEDs is the place to go.

I recently stumbled across a disturbing post on a forum. In it, the author gushed about taking prescription stimulants to ensure weight loss and keep it off. A chorus of approval followed, with no regards to side effects and no qualms about lying to get the pills.

The association between drug abuse and eating disorders (EDs) isn’t new. Or even surprising. Since the 1970s, doctors have reported higher incidents of self-medication and drug abuse in a subset of eating disorder patients. Drugs, in this context, cover everything from laxatives, diet pills, alcohol to street drugs. What’s shocking is the extent of the problem. In a report detailing the most comprehensive review on the topic, the National Center on Addiction and Substance Abuse concluded: “Individuals with eating disorders are up to five times likelier to abuse alcohol or illicit drugs and those who abuses alcohol or illicit drugs are up to 11 times likelier to have eating disorders”.

The report is available online for free, and I highly recommend reading the entire document. However, if you’re pressed on time, here are some of their main findings.

The link is strong: Between 30-50% of bulimia nervosa (BN) patients and between 12-18% anorexia nervosa (AN) patients abuse or are dependent on alcohol or drugs, compared to roughly 9% of the general population. This may be an underestimation, as the rates do not include many individual with eating disorders who smoke or abuse prescription medication. Eating disorders not otherwise specified (EDNOS) and Binge eating disorder (BED) does not seem to be included in these rates, and no further explanation was given. However, the report did note that individual with BED are more likely than obese individuals to abuse illicit drugs.
The link is reciprocal: Up to 35% of individuals who abuse or are dependent on alcohol or drugs also have an eating disorder, compared to up to 3% in the general population.
The link starts young and occurs even in sub-clinical cases: Preadolescent and adolescent girls and boys with strong weight concerns are roughly twice as likely to start smoking or smoke daily than those less concerned about their weight. A similar correlation in seen with drinking, where girls who engage in unhealthy dieting behaviors (fasting, diet pills, or binging and purging) as twice as likely to begin drinking and drink considerably more than non-dieting peers.
The link between alcohol/illicit drug use is stronger for BN than AN. Alcohol abuse is more common in people with bulimia, who report higher rates of suicide attempts, anxiety/personality/conduct disorders and other substance dependence than non-alcoholic BN patients. BN patients, compared to AN patients, are more likely to have abused amphetamines, barbiturates, marijuana, tranquilizers and cocaine. The highest rate of illicit drug use is associated with BN binge-purge type, some of whom use heroin to facilitate vomiting. Stimulants (cocaine, Ritalin and Adderall) are used to suppress appetite and to induce a sense of self-control. Similar results are found in a sample of women including both college students and community members, who exhibit disordered eating behaviors but do not have an ED diagnosis.
The report points to a rise in ED occurrence in males, athletes and racial/ethnic minorities, but did not have any data on concurrent drug abuse in this population.
The casual relationship between ED and drug abuse is not well understood.

EDs and substance abuse have many shared risk factors, which may explain the high rate of co-occurrence. These include:

Biological factors: Both disorders operate on the same reward and motivational systems in the brain, precipitating an obsessive preoccupation with a substance, intense cravings and compulsive behavior.
Personality risks: Both disorders may represent ways for certain people to cope with stress and transition. High-risk personality traits include low self-esteem, depression and anxiety. The strong link between BN and drug abuse may be partially explained by high impulsivity in individuals with both disorders.
Parental and environmental risks: Both disorders may be influenced by unhealthy parental behavior, social pressure and the advertising, marketing and entertainment industries.

It is difficult to pinpoint which risk factors are the main contributors to the development of each or both disorders. However, these shared traits may explain why in some cases ED predisposes the individual to substance abuse (and vise-versa).

The prevention and treatment of co-occurring EDs and substance abuse will have to depend on many parties, including parents, schools, health professionals, policy makers and researchers. Parents and schools are especially important in educating young individuals, by modeling and promoting messages about healthy eating and dangers of drug use. Health professionals need to recognize and screen for the co-occurrence of both disorders. Unfortunately, at the time of the report (late 2003), few effective treatment programs exist for addressing both disorders simultaneously. At the moment, the body of literature concerning this topic tends to be more descriptive (“a link exists”) than mechanistic (“this is why is exists”).

Researchers will need to work with clinicians to develop better approaches to preventing, assessing, diagnosing and treating substance abuse and eating disorders. Specific guidelines are outlined in Chapters 3 and 4 of the report.

Finally, the dangers of co-occurring drug abuse and ED cannot be overstated. ED patients often suffer hair loss, tooth decay, osteoporosis, and weakening of the heart. Stimulants, such as Adderall, Ritalin, cocaine and nicotine (found in tobacco) further stress the cardiovascular system, which can lead to high blood pressure, stroke and even heart failure. With the rise of “study drug” abuse in both students and professionals, these dangerous consequences are becoming increasingly relevant to those with EDs.

Once again, I recommend reading the full report “Food for Thought: Substance Abuse and Eating Disorders” (link here, pdf warning). I’d love to hear your thoughts: why do you think some individuals with EDs are more likely to abuse drugs? Or is substance abuse inherent in some types of EDs, as a symptom?