MONTREAL – Comorbid eating disorders and substance abuse are intertwined behaviorally and biologically, so the treatment of both problems must be an integrated effort, Cynthia M. Bulik, Ph.D., said at an international conference sponsored by the Academy for Eating Disorders.
And with growing numbers of middle-aged women presenting to eating disorder programs, substance abuse comorbidity is being seen more frequently than in the teenage population, she said.
“We don't have sufficient integrated treatment programs, so often patients will go to substance abuse programs which either ignore or are ill equipped to deal with their eating disorder, and then they are sent to an eating disorders program without necessarily the proper follow-up for their substance abuse,” said Dr. Bulik, professor of eating disorders and nutrition at the University of North Carolina, Chapel Hill.
Although the abuse of certain substances, such as laxatives or diet pills, may have superficial connections to the desire for weight loss, the abuse is almost always intertwined with other complex psychiatric issues, Dr. Bulik explained.
“If we try to discourage a patient from abusing laxatives by pointing out that they are ineffective as weight loss agents, we are missing the mark clinically, because there's a real self-harm component to this behavior,” she said in an interview. “When a person takes 50 laxatives a day, it hurts, there's incredible cramping and diarrhea, it keeps them up at night, and it's very painful. If we fail to address this whole self-punishing aspect, we're really not addressing their needs.”
Indeed, she and her associates have found that laxative abuse, most common among patients with purging anorexia (72%) and combined anorexia and bulimia nervosa (59%), is associated with a significantly higher prevalence of borderline personality disorder–characterized particularly by feelings of suicidality, self-harm, emptiness, and anger, she reported.
In another study, they found that alcohol abuse is more prevalent in patients with bulimia nervosa (46%) and combined bulimia and anorexia nervosa (37%), compared with those with anorexia (16%) alone (J. Clin. Psychiatry 2004;65:1000–6). Other studies have suggested anywhere from two to six times the risk of alcohol dependency in the eating disordered population, compared with the general population, she said.
As with laxative abuse, alcohol abuse in patients with eating disorders occurs with other psychiatric comorbidities such as major depressive disorder, obsessive compulsive disorder, posttraumatic stress disorder, social phobia, borderline personality disorder, and perfectionism–all of which need to be evaluated and treated, Dr. Bulik said.
In addition, other drugs such as nicotine and caffeine should be considered more problematic in patients with eating disorders than in healthy individuals, she said. In such patients, these drugs can actually be part of the eating disorder.
Research suggests that smoking can significantly increase resting energy expenditure, making it counterproductive to treatment because it can interfere with the treatment goal of weight restoration; caffeine is used to overcome some of the fatigue caused by undernourishment.
“There's both a cognitive component and a physiologic component to this kind of drug use. Patients know that nicotine increases their metabolism, and they know that caffeine might be giving them false energy when they are not eating,” she said.
In addition, cravings for all drugs are enhanced with food deprivation, a neurobiologic factor that could interfere with drug abuse rehabilitation.
“People need reinforcers, and food is the major reinforcer. Just like in laboratory animals, when you take food away, they often turn to other substances,” Dr. Bulik said.
Careful attention to patterns and changes in patients' substance abuse can offer important insight when tracking their eating disorder, and vice versa. It can also help in the prediction or prevention of relapse.
As an example, she described a person who may have gained control of her eating disorder but not her alcohol abuse. Because alcohol disinhibits appetite, it could trigger binge eating that could trigger a relapse of the eating disorder. Similarly, if a patient is unable to decrease her nicotine consumption, this could be an indication that her eating disorder is not well controlled.
“We need to focus on integrated treatments where we are dealing with both things at the same time, looking at how they interrelate, understanding what some of the overarching integrators might be, and exploring how substances can influence relapse,” Dr. Bulik said.
