By JESSICA BAKER
Published: November 25, 2013
The treatment of anorexia nervosa (AN) can be challenging. Psychotherapy is often recognized as the treatment of choice; however, there have been few large-scale clinical trials examining the efficacy of different treatment methods. Clinical trials are important because they provide a means of assessing whether a specific method of treatment (e.g., psychotherapy, medication) is efficacious. They can also allow us to compare the efficacy of one treatment compared to another. For example, is cognitive behavioral therapy more efficacious than dialectical behavior therapy in the treatment of AN?
Conducting large-scale clinical trials comparing therapeutic approaches to AN has been challenging due to the fairly low prevalence of the disorder, the high drop out rate from treatment, and the hesitancy of individuals with AN to seek treatment for their disorder. Recently, the largest clinical trial to date was published in The Lancet, which is a high impact medical journal.
In this study, the authors compared three different psychotherapy treatment approaches for AN: focal psychodynamic therapy (FPT), enhanced cognitive behavior therapy (CBT-E), and optimized treatment as usual (O-TAU) for adults. Patients with AN were randomly assigned to one of the three treatment approaches. Outcomes were then compared after treatment was complete.
FPT: The general goals of FPT are to help patients develop an understanding of the meaning of food to them and find alternative ways to express distress and needs, with a specific focus on interpersonal relationships. It can be divided into three phases 1) developing the alliance between patient and therapist; self-esteem; eating disordered attitudes and behaviors viewed as acceptable by the patient; 2) focus on relevant relationships and the association between relationships and AN behavior; 3) planning for the end of treatment and transfer to everyday life.
CBT-E: CBT-E focuses on the beliefs, values, and cognitive processes that maintain eating disorder behaviors, aiming to modify distorted beliefs and attitudes about the meaning of weight, shape, and appearance. The CBT treatment plan consists of several different modules, which are the focus of treatment 1) motivation; 2) nutrition; 3) creating a personal formulation of AN; 4) cognitive restructuring; 5) mood regulation; 6) social skills; 7) body image; 8) self-esteem; and 9) relapse prevention.
OT: The clinical trial occurred in Germany, so treatment as usual was determined by German standards of care. This included providing patients with a referral list of eating disorder psychotherapists who work within Germany’s guidelines. The patient’s family doctor also had an active role in treatment and monitoring recovery.
After patients were assigned to one of the three treatment groups, they engaged in 10 months of treatment. Patients were assessed for eating disorder symptoms and weight status at the end of treatment and then 12 months later.
The authors had two primary hypotheses. First, they predicted that both FPT and CBT-E would be associated with a better outcome with respect to body mass index (BMI) at the end of treatment than O-TAU . Further, they hypothesized that both FPT and CBT-E would be associated with higher recovery rates at 12 month follow-up than O-TAU.
Just to note how difficult it can be to conduct these studies, 30% of the patients in the study dropped out before treatment ended—and this is a comparatively low drop out rate for an AN treatment study.
At the end of treatment, patients in all treatment groups showed weight gain from the start of treatment. There were, however, no differences across the three treatment groups in the amount of weight gained. However, patients who had a starting BMI of <17.5 gained more weight by end of treatment in CBT vs. FPT treatment.
Further, at the 12-month follow-up, patients in all three treatment groups continued to see some improvement in weight and, again, no differences were observed across groups.
At the 12-month follow-up point, 21%, 22%, and 28% of patients in the FPT, CBT-E, and O-TAU treatments, respectively still met diagnostic criteria for AN. However, patients assigned to FPT were significantly more likely to be recovered at 12-month follow-up compared with patients receiving O-TAU (35% vs. 13%).
Some other interesting findings observed—CBT-E was associated with a more rapid weight gain over the course of treatment, and FPT patients required fewer inpatient admissions during the course of the trial.
There are promising findings in this trial. Regardless of which treatment group patients were assigned to, similar weight gain was observed. On average, patients gained 8lbs from beginning of treatment to 12-month follow-up. These findings are important because not everyone has access to a provider who has specialist eating disorders treatment training. As observed in the O-TAU group, linking family physicians with eating disorder treatment centers may be an effective approach in AN treatment which specialist services are not available.
Although promising, the results aren’t strong enough. There remains plenty of room for improvement on our ability to treat AN. Up to 41% of patients who completed treatment still had a BMI <17.5 (i.e., underweight) at the 12-month follow-up point. In addition, weight is only one slice of the recovery picture in AN. While the authors did assess some cognitive symptoms, we cannot say someone is “recovered” simply by measuring their BMI. It is not uncommon for patients to reach a healthy weight and stop engaging in eating disorder behaviors yet still experience significant and intrusive eating disorder thoughts and body dissatisfaction.
Although a very important contribution to the clinical literature, the drop out rates and percentages of patients still unwell at the end of treatment do encourage us to continue searching for treatments that are both effective and tolerable to patients. Further studies should develop new approaches and explore how to modify existing approaches to enhance recovery.
Focal psychodynamic therapy, cognitive behaviour therapy, and optimised treatment as usual in outpatients with anorexia nervosa (ANTOP study): randomised controlled trial.
Zipfel S, Wild B, Groß G, Friederich HC, Teufel M, Schellberg D, Giel KE, de Zwaan M, Dinkel A, Herpertz S, Burgmer M, Löwe B, Tagay S, von Wietersheim J, Zeeck A, Schade-Brittinger C, Schauenburg H, Herzog W; on behalf of the ANTOP study group.
Lancet. 2013 Oct 11. doi:pii: S0140-6736(13)61746-8. 10.1016/S0140-6736(13)61746-8. PMID: 24131861
The challenges of treating anorexia nervosa.
Lancet. 2013 Oct 11. doi:pii: S0140-6736(13)61940-6. 10.1016/S0140-6736(13)61940-6. PMID: 24131860