The Diagnosis and Treatment of Eating Disorders

Background: Eating disorders are of major significance both in clinical medicine and in society at large. Anorexia and bulimia nervosa almost exclusively afflict young persons, severely impairing their physical and mental health. The peak ages for these diseases are in late adolescence and young adulthood; patients therefore suffer setbacks both in school and/or in their occupational careers. This scientifically based S3 guideline was developed with the intention of improving the treatment of eating disorders and motivating future research in this area.

Methods: The existing national and international guidelines on the three types of eating disorders were synoptically compared, the literature on the subject was systematically searched, and meta-analyses on bulimia nervosa and binge-eating disorder were carried out. 15 consensus conferences were held, as a result of which 44 evidence-based recommendations were issued.

Results: Anorexia and bulimia nervosa are diagnosed according to the ICD-10 criteria (International Classification of Diseases), binge-eating disorder according to those of the DSM (Diagnostic and Statistical Manual of Mental Disorders). Psychotherapy is the mainstay of treatment for all three disorders, and cognitive behavioral therapy is the form of psychotherapy best supported by the available evidence. The administration of selective serotonin reuptake inhibitors (SSRI) can be recommended as a flanking measure in the treatment of bulimia nervosa only. The evidence does not support any type of pharmacotherapy for anorexia nervosa or binge-eating disorder. Bulimia nervosa and binge-eating disorder can usually be treated on an outpatient basis, as long as they are no more than moderately severe; full-fledged anorexia nervosa is generally an indication for in-hospital treatment.

Conclusion: This guideline contains evidence- and consensus-based recommendations for the diagnosis and treatment of eating disorders. If strictly implemented, it should result in improved care for the affected patients.

The main symptom of anorexia nervosa (AN) is self-induced malnutrition with weight loss that may amount to cachexia. According to the diagnostic criteria, the body weight is so low that health impairment is to be feared. In adults, this danger is seen when the body mass index (BMI) drops below 17.5kg/m²; in children and adolescents, it corresponds to being below the 10^th BMI-for-age percentile. Since children have a much smaller fat mass than adults or adolescents, the somatic sequelae of starving during AN occurring early in life are more serious and have negative consequences for, e.g., bone density, growth in height, and cerebral maturation. AN is often accompanied by other psychological illnesses such as depression, anxiety, or compulsive disorder. The average frequency of AN in young women aged between 14 and 20 years varies between 0.2% and 0.8% (1) (eBox 1 gif ppt).

The 10-year mortality in this group is around 5%. This is considerably more than 10 times the mortality from other causes in this age group in the general population (1, 2). Follow-up studies have shown that around 40% of patients with AN show good treatment success, while 25% have moderate and 30% poor treatment success (3).

The term “bulimia nervosa” (BN) refers to the uncontrollable urge for frequent high-calorie food. Episodes of excessive uncontrolled eating alternate with rigorous fasting, vomiting, and abuse of laxatives and/or diuretics. At 2%, BN has a notably higher prevalence than AN. Both of these eating disorders affect women in the large majority of cases; men are affected in only 5% to 10% of cases (1) (eBox 2 gif ppt).

According to studies in the USA, about 50% of patients with BN are free of symptoms after more than 5 years, while about 20% continue to fulfill all the criteria of the disorder (4).

The diagnosis “binge eating disorder” (BED) was incorporated by the American Psychiatric Association in the fourth revision of the Diagnostic and Statistic Manual of Mental Disorders (DSM-IV) in 1994 (5); in the International Classification of Diseases (ICD-10) it can only be coded under the category “eating disorder, unspecified” (F50.9). The course of BED has been the object of less research than AN and BN, but its prognosis is better. Remission rates in outpatient psychotherapy range between 50% and 80% (5–7) (eBox 3 gif ppt).

The prevalence of BED varies in the general population between 0.7% (8) and 4.3% (9); women are affected about 1.5 times as often as men (10).

The eating disorders AN and BN are of great social significance because they almost exclusively affect young people—with serious consequences for their physical and mental health. Overall, eating disorders give rise to enormous direct and indirect costs. Costs of 5300 EUR for AN and 1300 EUR for BN per patient per year are to be expected. Haas et al. (11) calculated an average of 4647 EUR in inpatient costs per patient. Krauth et al. (12) calculated overall costs of 12 800 EUR for a patient with AN. These costs are way above the average costs for inpatients with other diseases. So far as the authors know, no cost analyses have yet been done for BED .

Methods

The initiator of the S3 guideline was the German Society for Psychosomatic Medicine and Medical Psychotherapy (DGPM, Deutsche Gesellschaft für Psychosomatische Medizin und Ärztliche Psychotherapie) and the German College for Psychosomatic Medicine (DKPM, Deutsches Kollegium für Psychosomatische Medizin) in collaboration particularly with the German Society for Child and Adolescent Psychiatry, Psychosomatic Medicine, and Psychotherapy (DGKJP, Deutsche Gesellschaft für Kinder- und Jugendpsychiatrie, Psychosomatik und Psychotherapie) the German Association for Psychiatry, Psychotherapy, and Neurology (DGPPN, Deutsche Gesellschaft für Psychiatrie, Psychotherapie und Neurologie) and the German Psychological Society (DGPs, Deutsche Gesellschaft für Psychologie), supported by the Association of Scientific Medical Societies in Germany (AWMF, Arbeitsgemeinschaft der Wissenleschaftlichen Medizinischen Fachgesellschaften (Box 1 gif ppt). Following the procedure required by the AWMF, 44 statements and recommendations were agreed by consensus at a total of 15 meetings of experts and four moderated meetings. An attempt was made to integrate international guidelines: the British guideline from the National Institute for Health and Clinical Excellence (13) and the guideline of the American Psychiatric Association (14) were important sources. In addition, systematic literature searches and meta-analyses (15, 16) were carried out in order to include more recent studies, but also to allow for the fact that the recommendations in the Anglo-American guidelines do not always mesh with the German health care system.

As an example, the Figure (gif ppt) shows the literature search for studies on the treatment of AN.

Diagnosis

A preliminary diagnosis of AN in a young woman is easier than one of BN or BED, not least because of the patient is so under weight. Good indicators of BN are female sex, peak manifestation at the age of 18, weight fluctuations, and in particular emotional and mental fixation on body weight, eating, and physical activity. BED, unlike AN and BN, does not usually reach the level of a disorder except in the context of overweight and obesity, especially when the eating disorder is perceived both subjectively and objectively as counterproductive in the desire to lose weight. Diagnosis of an eating disorder requiring treatment should be on the basis of positive screening according to the criteria of ICD-10 (2) or DSM-IV (4) (Box 2 gif ppt).

In addition to measuring height and weight, the screening questions in Box 3 (gif ppt) are appropriate.

Because of the danger that eating disorders will become chronic, with physical and psychological complications, motivating the patient to undertake treatment is the focus of the first consultations. These should include giving comprehensive factual information about the eating disorder, including its risks, but without frightening the patient. In patients with AN in particular, cognitive impairment due to the cachexia must be taken into account. The information should include the causes and course of the disorder, and also its possible complications and co-morbidities. The formation of the therapeutic relationship is particularly important, whether the patient is an adult or a child or adolescent. Including parents or guardians in the therapeutic process is essential. A solid therapeutic relationship should be built up with both the child/adolescent and the parents, and if appropriate with any other significant persons.

Anorexia nervosa

Studies on the treatment of AN show only a moderate to low level of evidence, among other things because of low case numbers, the lack of valid control conditions, and the use of multimodal therapy approaches in which the individual treatment elements are not described. A meta-analysis shows large effect sizes (>1) (17) in relation to weight gain in both the outpatient (260 g/week) and the inpatient setting (530 g/week) (16). Controlled studies exist for cognitive behavioral therapy (CBT), interpersonal psychotherapy (IPT), psychodynamic therapy (PT), and family therapy, among others. However, these studies do not allow any conclusion about which method of treatment is to be preferred (level of evidence [LOE] Ib). A disorder-specific psychotherapy targeted at AN is, however, to be preferred over a nonspecific procedure (LOE II, grade of recommendation [GoR] B) (Table gif ppt).

Treating AN is a long process that will continue for months even if all goes well, and usually requires a management plan including inpatient, day patient, and outpatient treatment (LOE IV; GoR clinical consensus point [CCP]). However, there are no confirmed empirical data that allow an evidence-based decision for a particular setting (16). As a rule, for a patient with full-blown AN who is markedly under weight, treatment on an inpatient basis is indicated initially (GoR CCP).

The goal of treatment of AN is normalizing body weight and eating behavior and overcoming the psychological problems associated with AN. Clearly structured symptom-orientated treatment components are very important, especially at the start of treatment (GoR CCP), and as are considerations of nutrition management.

To achieve adequate weight gain requires an energy input considerably higher than what is needed for ordinary metabolism; how much higher depends on the patient’s body weight. During the initial therapy phase, patients may show a marked tendency to edema as part of a pseudo-Bartter syndrome, leading to a gain in weight without any substantial change in body mass. Patients with AN generally have an ambivalent attitude to changing their weight and eating behavior. Working to motivate them is therefore a central task of the therapist and should be kept in view throughout the entire treatment process (LOE III, GoR B).

Since the low body weight often leads to a life-threatening condition, in rare cases, among patients with little insight into their disorder, forced treatment may be necessary. Forced treatment is experienced by the patients as extremely stressful and should therefore be avoided as much as possible through intensive motivational support and treatment. Should it still be necessary, it should only be performed in stages (arrangement of guardianship, compulsory admission, forced feeding) (GoR CCP).

Children and at least younger adolescents often are not yet sufficiently mature to be able to realize the gravity of the disease and the need for treatment; in these cases usually the parents or guardians are of prime importance in ensuring that treatment is arranged and carried out. For this reason, they should be given comprehensive information about the disorder and the treatment it requires (GoR CCP).

Psychopharmaceuticals have been shown to be ineffective in AN (LOE Ib). In patients who are constantly preoccupied with eating and weight-related anxiety, and in those with physical hyperactivity that cannot be controlled in any other way, the use of low-dose neuroleptics such as olanzapine may be justified, as an off-label medication on an individual basis (LOE II, GoR B). Drugs with low extrapyramidal side effects should be preferred. Antidepressants do not improve the course of AN (LOE Ia, GoR A). They are occasionally used to treat co-morbid depressive symptoms (Box 4 gif ppt).

Bulimia nervosa

Bulimia nervosa is often accompanied by psychological disorders, such as depression, anxiety, and personality disorders, which can be severe; often these must be regarded as separate conditions and they need to be taken into account in the treatment plan (18). The symptom burden is higher in co-morbid patients and the level of psychosocial functioning more impaired. In diagnosing BN, it is important to obtain data from the life areas listed in Box 5 (gif ppt).

Psychotherapeutic methods have been shown to be effective and are the treatment methods of choice (LOE Ia, GoR A). In relation to the core symptoms—loss of control in eating, and vomiting as the most frequent compensatory behavior—they achieve moderate to large effect sizes (mean reduction by 70%, Cohen’s d = 0.78; or 67%, Cohen’s d = 0.94; post-effect sizes).

Cognitive behavioral therapy (CBT) for BN (CBT-BN) is the psychotherapeutic method that has been most researched and for which the highest level of evidence exists, and it should therefore be offered to patients with BN as the treatment of choice (LOE Ia, GoR B).

Interpersonal psychotherapy (IPT) shows a comparable efficacy to CBT (ES Ib, GoR B), but is not licensed as an insurance refunded psychotherapy in Germany.

Other psychotherapies are possible if CBT is not available, appears to be ineffective in a particular case, or is not wanted (LOE II, GoR B). Psychodynamic therapy (PT) may be recommended as an alternative (LOE II, GoR 0).

Even in uncomplicated cases of BN, treatment should last for at least 25 sessions at a frequency of 1 therapy session per week (GoR CCP). In more complex cases or those with more extensive psychological co-morbidity, much longer treatment is necessary (GoR CCP). Self-help programs have long been under discussion as an alternative to existing psychotherapeutic and pharmacologic treatments, sometimes in the context of “stepped care models.” Most of them are based on therapy manuals that contain the essential elements of CBT. The effects of self-help programs are smaller than those of the psychotherapies, but have nevertheless been clearly demonstrated (eating binges reduced by 57%, Cohen’s d = 0.68; vomiting reduced by 50%, Cohen’s d = 0.21). For some patients, a guided self-help program may be sufficient therapy.

In the pharmacotherapy of BN, selective serotonin reuptake inhibitors (SSRIs) represent the first choice of drug therapy in terms of symptom reduction, adverse effects profile, and patient acceptance (LOE Ia, GoR B). However, the efficacy of SSRIs on the core symptoms of BN is relatively weak (binge eating: Cohen’s d = 0.22; vomiting: Cohen’s d = 0.18). In Germany, the only substance licensed for the treatment of BN is fluoxetine in combination with psychotherapy, and then only in adults (LOE Ia, GoR B). The effective dose of fluoxetine in BN is 60 mg/day (LOE Ib, GoR B). Any attempt at treatment should be for not less than 4 weeks. If treatment is successful, it should be assumed that it should be continued for some time (GoR CCP) (Box 6 gif ppt).

Binge eating disorder

The aim of most patients with BED is usually to receive treatment for their co-existing obesity, i.e., they want to lose weight. This desire must be taken into account in the treatment or treatment plan for BED and must be carefully discussed with the patient. The various aspects of the therapeutic goals are shown in eBox 4 (gif ppt).

Psychotherapeutic studies of BED are mainly based on CBT, a few of them on IPT. While BED-adapted CBT (CBT-BED) in particular is very effective in terms of symptoms, i.e., on the frequency of bingeing or the number of days with binges (d = 0.82–1.04; LOE Ia, GoR A), only small effects are shown in terms of weight loss. More recent studies have also shown IPT to be effective (LOE Ib) (19). Interventions on the basis of guided self-help manuals largely correspond to those of CBT-BED. The interventions are classified as highly effective in terms of reduction of the frequency of bingeing (d = 0.84; LOE Ib, GoR B). In terms of weight reduction, however, no effects are seen here either. As a proviso, it needs to be said that the number of studies on self-help is small.

In Germany, no drug is officially licensed for the treatment of BED (off-label use). Patients with BED who receive antidepressants (tricyclic antidepressants, SSRIs, serotonin-norepinephrine reuptake inhibitors) and anticonvulsants (topiramate and zonisamide) had higher remission rates for binge eating frequency than those who received placebo (d = 0.52; LOE Ia, GoR B), and co-morbid depressive symptoms also improved (20, 21). In a few studies weight reduction is seen with certain drugs, but the dropout rate is very high (20, 21).

Combining drug therapy with CBT does not lead to additional effects in terms of the symptoms of the eating disorder, but has small effects for weight loss. CBT-BED appears to be superior to pure pharmacotherapy (fluoxetine, fluvoxamine) (21, 22). Obese patients with BED appear to benefit from weight reduction programs as much as obese patients without BED (LOE Ib) (23). BED-adapted CBT shows no extra effects on weight compared with ordinary, conservative weight reduction measures, which as a rule also contain treatment elements from behavioral therapy (5, 23, 24) (LOE Ib–IIb). Although more recent studies were unable to show a correlation between calorie-restrictive nutrition (hypocaloric diet) and exacerbation of BED symptoms (LOE IIa, IIb) (25), it ought at least to be investigated whether BED is regularly preceded by dieting. As in BN, it does not appear to be sensible to recommend restrictive eating behavior, with the aim of losing weight, and undertaking treatment for BED at the same time. The criteria for inpatient treatment for BN and BED are listed in Box 7 (gif ppt).

The S3 guideline is accessible on the AWMF website: www.awmf.org/leitlinien/detail/ll/051–026.html.

Acknowledgment

The authors of this article wish to thank the following for their commitment, for helping to organize the expert meetings, for moderating, and for their contributions to discussions, all of which contributed to the successful completion of this guideline: Prof. Ina Kopp (AWMF), for moderating the consensus meeting for the S3 Guideline on the Diagnosis and Treatment of Eating Disorders; Kristiane Göpel, Tübingen (VAKJP); Timo Harfst, Berlin (BPtK); Dr. Claus-Dieter Munz, Stuttgart (DGPT); Prof. Günter Reich, Göttingen (DGPT); Dr. Ingo Spitzczok von Brisinski, Viersen (BKJPP); Dr. Wally Wünsch-Leiteritz, Bad Bevensen (BFE).

Conflict of interest statement
Professor Herpertz has received lecture fees from Lilly, Lundbeck and Pfizer.
Dr. Hagenah has received lecture fees from AstraZeneca and Medice.
Dr. Vocks, Prof. von Wietersheim, Dr. Cuntz and Prof. Zeeck declare that no conflict of interest exists.

Manuscript received on 31 May 2011, revised version accepted on 6 June 2011.

Translated from the original German by Kersti Wagstaff MA.

Corresponding author

Prof. Dr. med. Stephan Herpertz

Klinik für Psychosomatische Medizin und Psychotherapie

LWL-Universitätsklinikum der Ruhr-Universität Bochum

Alexandrinenstr. 1–3
44791 Bochum, Germany

@eBoxes available at:
www.aerzteblatt-international.de/11m0678

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