Abstract
Anorexia nervosa (AN) is a serious health condition with insufficient treatment options. Radically Open Dialectical Behavior Therapy (RO-DBT) offers a new treatment approach targeting maladaptive overcontrol, a proposed underlying mechanism in AN. This study evaluated the feasibility, acceptability, and the preliminary efficacy of a 32-week standard RO-DBT intervention for individuals with AN in an outpatient setting. Twenty-three participants with AN (median age 20 years; median illness duration 5 years; 95.7% female) were included. Feasibility was demonstrated by a high retention rate (83%) and satisfactory completion of outcome measures, while acceptability was demonstrated by high treatment satisfaction. Participation in RO-DBT was associated with significant reductions in eating disorder psychopathology (95% CI: 0.34-1.45, Cohen's d = 0.90), significant increase in BMI (95% CI: 0.22-1.24, Cohen's d = 0.74), and increased use of the emotion regulation strategy cognitive reappraisal (95% CI: 0.19-1.20, Cohen's d = 0.70). These findings suggest that RO-DBT is a feasible, acceptable, and potentially effective treatment for AN.