There are no evidence-based treatments for severe and enduring anorexia nervosa.

To evaluate the relative efficacy of Cognitive Behavioral Therapy (CBT) and Specialist Supportive Clinical Management (SSCM) for adults with severe and enduring anorexia nervosa.

Randomised controlled trial.

Sixty-three participants aged 18 and over (range 20-62) with a DSM-IV diagnosis of anorexia nervosa with at least a seven year illness history.

Thirty outpatient visits over 8 months. Participants were assessed at baseline, end of treatment (EOT), and 6-month and 12-month post-treatment follow-up. At EOP and follow-up, both groups improved significantly on the majority of outcome measures. However, there were no differences between treatment groups at EOT. At 6- and 12-month follow-up, analyses indicate greater improvement for those in CBT compared to SSCM. At 6-month follow-up, CBT participants had higher scores on the social adjustment scale (p = .038), and at 12-month they reported lower eating disorder examination global score (p = .004), and higher readiness for recovery (p = .013) compared to SSCM.

Patients with severe and enduring anorexia nervosa can make significant and meaningful improvements with therapy. CBT shows significant advantage over SSCM in terms of social adjustment, core eating pathology, and readiness for change over time.