A Dangerous Comorbidity: Eating Disorders and Substance Abuse

More Highlights from the International Conference in Montreal

Comorbidity can have serious consequences when a patient with an eating disorder also has substance abuse problems, according to Dr. Cynthia Bulik, professor at the University of North Carolina, Chapel Hill. Dr. Bulik, speaking at the National Institute of Mental Health Plenary Session II, “Does Comorbidity Matter?” urged clinicians to devote more time to talking with these patients, to better understand the relationship between the eating disorder and substance abuse.

Dr. Bulik added, “Assess every patient comprehensively for an array of substance abuse problems. If you don’t ask, you’re not going to get an answer. Think about the fact the substance use disorder can be part of the eating disorder. Look at the role of relapse and substance abuse.”

How the relationship develops

How does someone go from an eating disorder to substance abuse, or visa versa? According to Dr. Bulik, studies show that the majority of individuals either developed both an eating disorder and substance abuse disorder in the same year, or the eating disorder came first. One of the few causal factors identified among people who developed alcohol abuse was perceived parental criticism, as reported on the multidimensional perfectionism scale.

Laxative abuse: serious consequences

Dr. Bulik also described the dangers of long-term laxative abuse, adding that 38% to75% of women with bulimia nervosa abuse laxatives. These products are ineffective for weight loss, she said, because less than 10% to12% of calories are excreted since laxatives work too low in the gastrointestinal system. Dr. Bulik quipped that the symptoms of diarrhea, weakness, cramping, dehydration, and loss of normal bowel function “certainly are not the ‘women’s gentle laxative’ that we see on TV.” Instead, laxatives are problematic drugs of abuse, which cause craving constipation and rebound edema. Patients who stop using laxatives often relapse, and start using them again. Patients may feel bloated and turn to laxatives for a quick escape from it, but clinicians need to be very vigilant to laxatives as relapse cues, she said.

Dr. Bulik noted that most persons who abuse laxatives don’t use these products alone; instead, laxatives are usually paired with vomiting. This is seen most commonly in the purging type of anorexia nervosa and among individuals with a history of AN and bulimia nervosa. In recent studies, laxative abuse has been associated, across the board, with worse eating disorder pathology and general psychopathology and a higher incidence of borderline personality disorder. Dr. Bulik and colleagues found that this last group had higher suicidality, feelings of emptiness, self-harm, and anger. Dr. Bulik added, “If we just focus on laxative abuse as an ineffective way to lose weight or for purging weight, when in reality patients are using this as self-harm, we are missing the mark and not really giving them the intervention they require.”

Smoking: addictive and metabolic changes

Dr. Bulik reported that the prevalence of smoking among women with eating disorders is very high, and with this comes increased amphetamine, cannabis, and cocaine use. Once a patient is discharged, the urge for smoking cigarettes and caffeine increases as patients have difficulties with weight gain in more unstructured settings. The highest rates of smoking are 75% in individuals with purging BN and 60% in those with anorexia nervosa binge purge subtype.

Dr. Bulik explained that patients may not be gaining weight in more unstructured environments. In partial hospitalization programs, the ratio resting energy expenditure to free fat mass is increased with smoking. A patient may be on a break smoking and thereby is increasing her energy expenditure. Meanwhile clinicians are feeding them in a manner that should help them maintain their weight, but becomes harder and harder for patients to maintain their weight.

Emetics: a cardiotoxic factor

Dr. Bulik pointed out that many women use emetics, and that 9% of women with BN report chronic use of emetics. An emetic acts directly on the gut to lead to immediate vomiting. This vomiting can go on for 24 hours, depending on the patient’s innate physiologic vulnerability, the effects of the drug and how much they took, she added. A very real problem is development of tolerance to the drug. Once tolerance develops, the patient may increase the dosage of Ipecac, for example, to get the same effect. At the same time, less of the drug is vomited out. Ipecac is highly cardiotoxic, and the clearance of the drug is less with longer-term use. Dr. Bulik advised the audience that discovering that patients use emetics is an immediate red flag. These patients need a cardiovascular examination and the clinician then must help patients get off these agents as quickly as possible, she added.

Artificial sweeteners

Dr. Bulik then turned to the peculiar overuse of artificial sweeteners seen among patients with eating disorders, particularly those who are regaining weight. It isn’t usual for patients to sneak down to the cafeteria and steal packets of sweeteners, and then to use an excess amount on their food, for example, seven packets of Sweet N’ Low ® on a banana. She noted that this puzzling behavior should be studied further because patients who use artificial sweeteners have an increased craving for sweetness—Splenda® is actually 600 times sweeter than sugar, she said. As a result of using these sweeteners, people might also be increasing their intake to satisfy this craving. The underlying cause is yet to be explained—is it cognitive or something neurobiological?

Starvation and the reinforcing efficacy of drugs

Animal studies have added to knowledge of the mechanisms underlying drug use in humans, she said. When rats are starved, for example, the reinforcing efficacy of drugs is increased. The effect of food restriction is robust across all species, she said, including rodents, monkeys and humans, and across all routes of administration.

There is very little empirical guidance about how to treat people with eating disorders and substance abuse, Dr. Bulik said, adding that rigorous empirical trials are needed. She pointed out an increasing incidence of eating disorders among middle-aged women who also abuse alcohol. These women have more access to alcohol than teenage patients, and this comorbidity will become more important in time.

Finally, she added, overlooking the dangers of substance abuse in eating disorders patients may be precarious. Commonly used substances may influence weight gain and metabolism. Ongoing substance use may reflect underlying eating disordered cognitions or ongoing food deprivation, and the neurobiology of food deprivation and substance abuse may be intertwined, she added.

A Dangerous Comorbidity: Eating Disorders and Substance Abuse

Comorbidity can have serious consequences when a patient with an eating disorder also has substance abuse problems, according to Dr. Cynthia Bulik, professor at the University of North Carolina, Chapel Hill. Dr. Bulik, speaking at the National Institute of Mental Health Plenary Session II, “Does Comorbidity Matter?” urged clinicians to devote more time to talking with these patients, to better understand the relationship between the eating disorder and substance abuse.

Dr. Bulik added, “Assess every patient comprehensively for an array of substance abuse problems. If you don’t ask, you’re not going to get an answer. Think about the fact the substance use disorder can be part of the eating disorder. Look at the role of relapse and substance abuse.”

How the relationship develops

How does someone go from an eating disorder to substance abuse, or visa versa? According to Dr. Bulik, studies show that the majority of individuals either developed both an eating disorder and substance abuse disorder in the same year, or the eating disorder came first. One of the few causal factors identified among people who developed alcohol abuse was perceived parental criticism, as reported on the multidimensional perfectionism scale.

Laxative abuse: serious consequences

Dr. Bulik also described the dangers of long-term laxative abuse, adding that 38% to75% of women with bulimia nervosa abuse laxatives. These products are ineffective for weight loss, she said, because less than 10% to12% of calories are excreted since laxatives work too low in the gastrointestinal system. Dr. Bulik quipped that the symptoms of diarrhea, weakness, cramping, dehydration, and loss of normal bowel function “certainly are not the ‘women’s gentle laxative’ that we see on TV.” Instead, laxatives are problematic drugs of abuse, which cause craving constipation and rebound edema. Patients who stop using laxatives often relapse, and start using them again. Patients may feel bloated and turn to laxatives for a quick escape from it, but clinicians need to be very vigilant to laxatives as relapse cues, she said.

Dr. Bulik noted that most persons who abuse laxatives don’t use these products alone; instead, laxatives are usually paired with vomiting. This is seen most commonly in the purging type of anorexia nervosa and among individuals with a history of AN and bulimia nervosa. In recent studies, laxative abuse has been associated, across the board, with worse eating disorder pathology and general psychopathology and a higher incidence of borderline personality disorder. Dr. Bulik and colleagues found that this last group had higher suicidality, feelings of emptiness, self-harm, and anger. Dr. Bulik added, “If we just focus on laxative abuse as an ineffective way to lose weight or for purging weight, when in reality patients are using this as self-harm, we are missing the mark and not really giving them the intervention they require.”

Smoking: addictive and metabolic changes

Dr. Bulik reported that the prevalence of smoking among women with eating disorders is very high, and with this comes increased amphetamine, cannabis, and cocaine use. Once a patient is discharged, the urge for smoking cigarettes and caffeine increases as patients have difficulties with weight gain in more unstructured settings. The highest rates of smoking are 75% in individuals with purging BN and 60% in those with anorexia nervosa binge purge subtype.

Dr. Bulik explained that patients may not be gaining weight in more unstructured environments. In partial hospitalization programs, the ratio resting energy expenditure to free fat mass is increased with smoking. A patient may be on a break smoking and thereby is increasing her energy expenditure. Meanwhile clinicians are feeding them in a manner that should help them maintain their weight, but becomes harder and harder for patients to maintain their weight.

Emetics: a cardiotoxic factor

Dr. Bulik pointed out that many women use emetics, and that 9% of women with BN report chronic use of emetics. An emetic acts directly on the gut to lead to immediate vomiting. This vomiting can go on for 24 hours, depending on the patient’s innate physiologic vulnerability, the effects of the drug and how much they took, she added. A very real problem is development of tolerance to the drug. Once tolerance develops, the patient may increase the dosage of Ipecac, for example, to get the same effect. At the same time, less of the drug is vomited out. Ipecac is highly cardiotoxic, and the clearance of the drug is less with longer-term use. Dr. Bulik advised the audience that discovering that patients use emetics is an immediate red flag. These patients need a cardiovascular examination and the clinician then must help patients get off these agents as quickly as possible, she added.

Artificial sweeteners

Dr. Bulik then turned to the peculiar overuse of artificial sweeteners seen among patients with eating disorders, particularly those who are regaining weight. It isn’t usual for patients to sneak down to the cafeteria and steal packets of sweeteners, and then to use an excess amount on their food, for example, seven packets of Sweet N’ Low ® on a banana. She noted that this puzzling behavior should be studied further because patients who use artificial sweeteners have an increased craving for sweetness—Splenda® is actually 600 times sweeter than sugar, she said. As a result of using these sweeteners, people might also be increasing their intake to satisfy this craving. The underlying cause is yet to be explained—is it cognitive or something neurobiological?

Starvation and the reinforcing efficacy of drugs

Animal studies have added to knowledge of the mechanisms underlying drug use in humans, she said. When rats are starved, for example, the reinforcing efficacy of drugs is increased. The effect of food restriction is robust across all species, she said, including rodents, monkeys and humans, and across all routes of administration.

There is very little empirical guidance about how to treat people with eating disorders and substance abuse, Dr. Bulik said, adding that rigorous empirical trials are needed. She pointed out an increasing incidence of eating disorders among middle-aged women who also abuse alcohol. These women have more access to alcohol than teenage patients, and this comorbidity will become more important in time.

Finally, she added, overlooking the dangers of substance abuse in eating disorders patients may be precarious. Commonly used substances may influence weight gain and metabolism. Ongoing substance use may reflect underlying eating disordered cognitions or ongoing food deprivation, and the neurobiology of food deprivation and substance abuse may be intertwined, she added.