One out of four patients with eating disorders drop out of psychotherapeutic treatment. The high rate of dropout calls for ways to improve treatment adherence. Research indicates that continuous feedback to patient and therapist during treatment reduces the number of dropout and increases outcome; however there are only two published randomised trials on the effect of feedback on the treatment of eating disorders showing inconclusive results, and there are no randomised trials on the effect of feedback in group therapy.

We are investigating the impact of continuous feedback on dropout and outcome in group therapy. The hypothesis is that continuous feedback to patient and therapist on treatment progress and alliance will

1. 1) reduce the number of dropouts and

2. 2) increase treatment outcome.

We aim to discover if feedback is a way of improving adherence in group therapy for outpatients with eating disorders.

The trial is set up in a randomised design with 196 outpatients diagnosed with bulimia nervosa, binge eating disorder or eating disorder not otherwise specified, according to the DSM-IV. They are allocated to

1. a) systemic and narrative group therapy with feedback intervention or

2. b) systemic and narrative group therapy as usual.

In the experimental group, two sets of feedback measures are added to the treatment as usual: the outcome rating scale and the group session rating scale.

If the results will confirm the hypothesis, this trial will support feedback as a way to improve treatment adherence for outpatients with eating disorders.