Background: Cognitive impairment is a core deficit in schizophrenia. This study aimed to evaluate the effectiveness of Metacognitive Training (MCT) in improving cognitive function in long-term hospitalized patients with schizophrenia using the Japanese version of the Montreal Cognitive Assessment (MoCA-J).
Methods: Participants were schizophrenia patients hospitalized for over one year in a psychiatric institution and receiving occupational therapy (OT). They were randomly assigned to two groups via stratified randomization: the OT+MCT group (n=21), which received MCT in addition to standard OT, and the OT-alone group (n=20), which received standard OT only. MCT was conducted for approximately four months, and cognitive function was assessed before and after the intervention using MoCA-J. The study was approved by the ethics committee.
Results: A comparison of total MoCA-J scores before and after intervention showed a significant improvement in the OT+MCT group (p < 0.01, d = 0.26), but not in the OT-alone group. Analysis of MoCA-J subdomains revealed that the OT+MCT group significantly improved in visuospatial/executive function, clock drawing, and attention, while the OT-alone group improved only in naming. When subdomains were categorized into six cognitive domains (executive function, visuospatial ability, language, attention, memory, and orientation), the OT+MCT group showed significant improvements in visuospatial ability and attention, whereas the OT-alone group improved only in language.
Conclusion: These findings suggest that MCT effectively enhances cognitive function in long-term hospitalized schizophrenia patients, as assessed by MoCA-J. The observed improvements in cognitive function indicate the potential of MCT to enhance occupational performance in this population.