Chronic Eating Disorders

Eating disorders in general and anorexia nervosa in particular are complex and difficult psychiatric disorders to treat. Empirical research has established effective treatments of bulimia nervosa. However, anorexia nervosa remains without effective empirically based treatments, especially for adult patients. A significant majority of patients with bulimia nervosa will have a good outcome; however, a small minority, approximately 10%, will be refractory to treatment.

In a review of anorexic inpatients and outpatients followed for a minimum of 4 years, good outcomes (weight restoration within 15% of recommended weight and regular menses) occurred in 44% of patients. Poor outcomes persisted in 24% of patients, and 28% had intermediate outcomes. An estimated 5% of patients died of the illness.¹ As the duration of follow-up gets longer, the numbers are even more dismal. At a 10-year follow-up, more than 30% of patients were found to have anorexia nervosa that was refractory to treatment, with a further 10% of patients dying of the disease.²

The focus of this review is to describe clinically driven treatment strategies for patients with treatment-refractory eating disorders. Having said that, there is no widely accepted definition of treatment resistance in this population and criteria for the duration of illness and numbers of failed treatments do not exist. For anorexia nervosa and bulimia nervosa, treatment resistance is equivalent to chronicity or, as Strober³ describes, “a permanence of the disease state in spite of repeated exposures to state-of-the-art therapy.”

One may consider the definition of treatment resistance in bulimia nervosa to be that of a patient whose condition has not responded to an adequate trial of an SSRI and evidence-based psychotherapy, such as cognitive-behavioral therapy (CBT). A definition of treatment resistance for anorexia nervosa (of which there are no evidence-based treatments) may include repeated failure to reach or maintain 85% of ideal body weight following multiple attempts with psychosocial interventions (eg, CBT and psychodynamic therapy), efforts to treat comorbid psychiatric illnesses, and repeated attempts at intensive refeeding (usually in specialized inpatient or outpatient programs). Unfortunately, there are no reliable predictors to determine whether a patient is likely to fall into this category of chronic and refractory illness and thus prevention and treatment are extreme-ly challenging.³

After providing a brief overview of the diagnostic and epidemiological issues relevant to anorexia nervosa and bulimia nervosa, we focus on the clinical approach for patients with eating disorders. We follow with a discussion of an innovative model of care for patients with refractory eating disorders.

Diagnosis

The diagnostic criteria for anorexia nervosa and bulimia nervosa have changed throughout the history of DSM, but the characteristic features of an overvaluation of weight and shape in combination with abnormal patterns of eating and weight regulation remain primary symptoms in both disorders. Although the lifetime prevalence of anorexia nervosa has not changed dramatically during the past 20 to 30 years, aspects of its epidemiology have changed.

Previously, it was thought to be an illness that primarily affected female adolescents of higher socioeconomic classes. It is now recognized that anorexia nervosa exists within all socioeconomic groups and that women are falling ill both earlier and later in life.⁴ Unlike that of anorexia nervosa, the prevalence of bulimia nervosa increased dramatically during the 1980s and 1990s; however, since 2000, the incidence has decreased substantially.⁵ Anorexia nervosa affects 0.3% to 0.7% and bulimia nervosa between 1.5% to 2.5% of females in the general population, and the male to female prevalence ratio ranges from 1:6 to 1:10.^6-8

Bulimia nervosa and anorexia nervosa are frequently chronic, unremitting conditions associated with significant morbidity and mortality. Standardized mortality rates in patients with anorexia nervosa are significantly higher than those in patients with any other mental illness, and anorexia nervosa has the highest death rate of any psychiatric disorder.⁹ Anorexic women are 12 times more likely to die than women of similar age in the general population; the most common causes of death are suicide and starvation-related medical complications. The suicide rate in anorexic females is reportedly 57 times higher than that in age-matched females in the general population.¹⁰

Treatment options

Based primarily on clinical experience, the mainstay of therapy for anorexia nervosa continues to be psychosocial interventions rather than medication. Pike and colleagues¹¹ were the first to demonstrate the efficacy of individual psychotherapy after resolution of the acute phase of illness and following weight gain. Anorexic patients who were treated with CBT had less relapse and a significantly longer time until relapse than those who received only nutritional counseling.