Clinical effectiveness of metacognitive training as a transdiagnostic program in routine clinical settings: A prospective, multicenter, single-group study

Aim: To evaluate the clinical effectiveness of metacognitive training (MCT) as a transdiagnostic program, on a diverse population with mental disorders in routine Japanese day-care settings.

Methods: This study employed a prospective, multicenter, single-group pre-post design. Participants diagnosed with various mental disorders received 10 MCT group sessions. We set transdiagnostic outcomes to assess quality of life, global functioning, cognitive insight, and depressive symptoms. At the end of the MCT, we also evaluated participants' satisfaction with treatment. Assessments were conducted at baseline (Pre), Week 5 (Mid), Week 10 (Post), and Week 14 (follow-up: FU).

Results: Thirty-four participants enrolled in the study and received MCT (schizophrenia = 22, non-schizophrenia = 12). Intent-to-treat analyses revealed significant improvements in quality of life/global functioning during the intervention period, and further improvements were observed during the follow-up (all p < .05). The Pre-FU treatment effect sizes for quality of life and global functioning were small (Hedge's g = 0.44 and 0.47, respectively). Significant improvements were also found in depressive symptoms during both the intervention and follow-up periods (all p < .05), but not in cognitive insight. Overall, participants were highly satisfied with the MCT content and format. Scores on almost all outcomes (except for depression) at each assessment point were not significantly different between the schizophrenic and non-schizophrenic sub-groups.

Conclusions: Despite several limitations, mainly due to small sample size and having no control conditions, our results suggest that MCT for a diverse population with mental disorders is a potentially effective approach in improving quality of life/global functioning and other clinical outcomes in routine day-care settings.