A Dutch group of Clinical Psychologists have published the results of a large scale trial examining the effects of MCT when compared with a form of CBT in the treatment of GAD. They report that both treatments were effective and that MCT was superior on most outcome measures. MCT produced recovery rates in worry in excess of 70% at post-treatment and at follow-up. These rates are consistent with those obtained in earlier trials of MCT and provide independent confirmation of the effectiveness of metacognitive therapy.
Reference: van der Heiden, C., Muris, C., and van der Molen, H.T. (2012). Randomized controlled trial on the effectiveness of metacognitive therapy and intolerance of uncertainty therapy for generalized anxiety disorder. Behaviour Research and Therapy, 50, 100-109.