The efficacy of extended metacognitive training for psychosis: A randomized controlled trial.

This study investigated the efficacy of 10-module metacognitive training (MCT) among Japanese patients with schizophrenia by conducting a multicenter randomized controlled trial to test the influence of the most recent and extended version of MCT on positive symptoms. A six-center, randomized, assessor-blind, controlled trial between "treatment as usual" (TAU) and TAU + MCT was conducted. Fifty inpatients and outpatients with schizophrenia, schizotypal, and delusional disorders (ICD 10) were enrolled, then randomly assigned to TAU (n = 26) or TAU + MCT (n = 24). Assessments were made at baseline, after six weeks, immediately posttreatment, and 1-month post-treatment. The primary outcome was positive symptom score, as measured by the Positive and Negative Syndrome Scale (PANSS). General assessment of functioning (GAF) and measures of cognitive biases were secondary outcomes. Completion at post-treatment (10 weeks later) and 1-month follow-up was high-TAU + MCT, n = 22 (91.67%) and TAU, n = 23 (88.46%). The severity of PANSS positive symptoms declined significantly in the TAU + MCT treatment group compared with the TAU group. GAF also showed significantly greater improvement in the TAU + MCT group compared with the TAU group. There was also a trend for greater efficacy of MCT on cognitive biases. In conclusion, this study provides support for the efficacy of 10 module MCT concerning positive symptomatology (especially, delusion) and general functioning.