A case series investigating acceptance and commitment therapy as a treatment for previously treated, unremitted patients with anorexia nervosa.

The aim of the present study was to evaluate the effectiveness of Acceptance and Commitment Therapy (ACT) for treatment of anorexia nervosa (AN) using a case series methodology among participants with a history of prior treatment for AN. Three participants enrolled; all completed the study. All participants had a history of 1-20 years of intensive eating disorder treatment prior to enrollment. Participants were seen for 17-19 twice-weekly sessions of manualized ACT. Symptoms were assessed at baseline, post-treatment and 1-year follow-up. All participants experienced clinically significant improvement on at least some measures; no participants worsened or lost weight even at 1-year follow-up. Simulation modelling analysis (SMA) revealed for some participants an increase in weight gain and a decrease in eating disorder symptoms during the treatment phase as compared to a baseline assessment phase. These data, although preliminary, suggest that ACT could be a promising treatment for subthreshold or clinical cases of AN, even with chronic participants or those with medical complications.