Study Compares Three Approaches to Treating AN

Some estimate that only 50% of those with anorexia nervosa (AN) who receive treatment fully recover, and that 20% remain chronically ill. And, in one 21-year follow-up study of 84 AN patients, the mortality rate was 16% (Psychol Med 2001; 31:88).

With these serious statistics in mind, an ongoing study of 237 outpatients randomly and evenly assigned to one of three treatment approaches is being conducted at 10 treatment centers in Germany. The researchers, led by Dr. Beate Wild, are comparing the effects of focal psychodynamic psychotherapy(FTP), cognitive behavioral therapy (CBT), and a control group receiving treatment as usual in patients with AN (Trials 2009; 10:23).

In the ANTOP (Anorexia Nervosa Treatment of Outpatients) Study, treatment for both the FPT and CBT groups are individual outpatient interventions and are based upon standardized treatment manuals. In both intervention groups, patients are treated with 40 sessions over 10 months. Patients are 18 years or older, with body mass indexes (BMIs) less than 18.5 kg/m2. Patients randomly assigned to a control group (treatment as usual) are given support for further treatment planning and provided with a list of established outpatient therapists. The control group was developed because studies that imposed wait list condition in AN patients posed dropout rates up to 70%; in another study, a control arm that used dietary advice had an overall 73% treatment failure rate.

The primary outcome measure for all three groups is their BMI at the end of the treatment or 10 months after randomization.

The two intervention approaches are audiotaped to monitor adherence to treatment manuals and every ninth audiotape is checked by monitors in Tubingen (CBT) or Heidelberg (FPT). The two treatments are provided by different therapists. The CBT treatment plan includes several treatment modules, based on the work of Fairburn. The treatment focuses on educating patients abut underweight and starvation as well as on developing regular dietary habits and weight gain. If a patient in the intervention groups has a BMI that falls below 14, outpatient treatment is stopped and the patient is hospitalized. When treatment leads to an increase in the BMI over 14, outpatient treatment is resumed. If after 4 weeks there is no improvement, the patient is withdrawn from the intervention group treatment. The treatment staff is in regular contact with the control groups general practitioners and arrange more intensive treatment if necessary.

The authors note that this is the first multicenter trial that include a sample size of adults with AN that is large enough to detect a reasonable effect size. Although they anticipate a dropout rate of as many as 30% of the participants, the goal is to find the most effective treatment for AN by monitoring body weight, eating-disorder-related symptoms and variables of compliance with treatment.