What Are Substance Use Disorders?

Substance use disorders encompass a wide variety of problems related to the use of drugs. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) recognizes substance-related disorders resulting from the use of 10 separate classes of drugs including alcohol, caffeine, marijuana, and opioids. It divides the disorders into two groups: substance-use disorders and substance-induced disorders. Substance use disorders are behaviors related to the use of a substance. By contrast, substance-induced disorders refer to the intoxication effects of a particular substance and the effects of discontinuing it, as well as the different disorders that substances can induce.

Prevalence and Comorbidity

The rate of co-occurrence of eating disorders and substance use varies greatly from study to study—from 17 percent to 46 percent. Some of this variance arises from what is measured. For instance, which population is being studied (such as a community-based versus a treatment-based study population), which eating disorders, which substances, and the degree of use (from one-time to physiological dependence) will all affect results. To date, the majority of eating disorder research has focused on women, although the few studies that include men show similar prevalence rates of comorbid disorders. They also reported that over 35 percent of the people who abused substances also had an eating disorder.

Which Eating Disorders and Which Substances?

Most research reports a stronger association between bulimia nervosa and substance abuse than between anorexia nervosa and substance use. Patients with bulimia nervosa and anorexia binge eating/purging type are the most likely to use substances. Patients with bulimia nervosa have the highest rates of alcohol consumption compared to all other types of eating disorders. Patients with anorexia nervosa-restricting type have been found to be the least likely to use alcohol compared to other subgroups of eating disorder patients. They are also the least likely to use other substances. Individuals with eating disorders use and abuse a variety of substances. The substances used with the highest prevalence among patients with eating disorders are sedatives, marijuana, and caffeine pills. Other substances reported include stimulants, hallucinogens, opiates, cocaine/crack, phencyclidine, and inhalants. Individuals with eating disorders may also use and abuse legal substances such as laxatives, diuretics, diet pills, thyroid hormones, nicotine, and artificial sweeteners.

The associations between eating disorders and substance use are complex and not fully understood. Some patients report that they seek substances such as methamphetamines or diet pills to try to reduce their weight. Other patients report that they develop an eating disorder after their weight or appetite has been suppressed by drug use. One study found that women with bulimia nervosa were turning to substances in order to dampen urges to binge eat while women with anorexia nervosa were using substances in order to lose weight.

Theories

There are several theories about why these two disorders might co-occur. Some of the proposed explanations include eating disorders themselves being a type of addiction, shared genetic and biological factors, and shared environmental risk factors such as trauma. Recent research suggests that eating disorders and SUDs share genetic underpinnings. Bulimia nervosa and substance use disorders appear to share some behavioral traits such as increased impulsivity that may predispose individuals to the development of both disorders. It is proposed that both disorders share several risk factors, including:

Shared brain chemistry (impact on dopamine and serotonin brain systems) Common family history (A family history of either substance abuse or eating disorders may increase the risk for the development of the other disorder.) Low self-esteem, depression, or anxiety Onset after stressful events Unhealthy social norms and peer pressure Vulnerability to messages from advertising and media History of childhood abuse

Patients with eating disorders who also have a SUD have a more severe eating disorder and SUD symptoms, have higher relapse rates, have more severe medical complications, and are more seriously impaired than individuals with eating disorders alone. Both eating disorders and SUDs can lead to death; research suggests that when combined the mortality rate is even greater than the mortality rate for each alone.

Assessment and Treatment Implications

Because of the high comorbidity between eating disorders and substance use disorders, anyone being treated for one should always be assessed for the other. Unfortunately, treatment professionals trained in the detection and treatment of one may not be trained in the detection and treatment of the other. Eating disorders and SUDs are distinct disorders that have been understood and treated differently.

SUD Treatment

Treatment for SUDs is designed to help patients increase restraint and abstinence from substances. Individuals with SUDs are strongly encouraged to participate in self-help programs such as Alcoholics Anonymous which is believed to decrease the potential for relapse.

Eating Disorder Treatment

By contrast, recovery from eating disorders is conceptualized differently, requiring aggressive psychological intervention, dietary support, and medical management. One of the primary goals of treatment is to reduce overcontrol and eliminate dieting, food restriction, and compensatory behaviors while normalizing eating patterns. Self-help programs are not historically considered an important component of eating disorder treatment or relapse prevention.

Co-Treatment

Eating disorders and substance use disorders are rarely treated together in a comprehensive manner. Substance abuse programs often do not admit patients with active eating disorders. Similarly, eating disorder treatment programs often exclude patients who use alcohol or illicit drugs while they may admit patients who use over the counter laxatives, diuretics, or diet pills. As a result, a majority of the treatments provided are in a sequential or parallel manner, and integrated treatments programs are lacking. This lack of access to integrated treatment may increase time and cost and can leave patients diagnosed with both disorders vacillating between the two disorders. It is not uncommon for patients being treated for substance abuse to experience an increase in eating disorder symptoms as they begin working on recovery. Similarly, patients in eating disorder treatment may increase their substance use when attempting to stabilize their eating and eliminate eating disorder behaviors. Sometimes inpatient or residential treatment may be necessary for patients with both eating disorders and SUDs. Both disorders increase the risk for medical problems so medical oversight is important. Experts advise caution when using medication for the treatment of comorbid eating disorders and substance abuse because a starved body can be unpredictable in processing substances. Similarly, chemical dependency professionals may encourage dietary changes and exercise which can exacerbate symptoms of eating disorders. There is a tendency by some SUD treatment professionals to view an eating disorder as an addiction. However, there is a lack of evidence for an addiction model for eating disorders. It is important that patients with comorbid eating disorders and SUDs learn that while they can be abstinent from substances, that food is a basic need and a moderation model is best. So while they will need to increase control over substances, they actually need to decrease rigid control over eating. An integrated treatment approach that simultaneously addresses both disorders seems best when it is available. Note that a related issue at the intersection of eating disorders and substance use disorders is what is often referred to as drunkorexia, or deliberately eating less food prior to alcohol use in an effort to compensate for alcohol calories that one is planning to consume.

A Word From Verywell

If you or someone you love is struggling with an eating disorder and substance abuse, please seek help from a trained professional who can provide treatment recommendations. Early intervention improves the outcome for both as well as combined conditions.