Immediate and Sustained Outcomes and Moderators Associated With Metacognitive Training for Psychosis A Systematic Review and Meta-analysis

IMPORTANCE A substantial increase in the number of trials examiningmetacognitive training (MCT) for psychosis necessitates an updated examination of the outcomes associated with MCT. OBJECTIVES To review the immediate and sustained associations of MCT with proximal (directly targeted) and distal (indirectly influenced) outcomes and assess treatment- and participant-related moderators to identify the potential factors associated with the expected heterogeneity of effect sizes. DATA SOURCES Eleven electronic databases were searched from 2007 to June 3, 2021 (alert until September 10, 2021). Reference lists of earlier meta-analyses and included reports were screened. STUDY SELECTION Reports examined MCT and included participants with schizophrenia spectrum and related psychotic disorders (1045 reports identified; 281 assessed). There were no age, sex, gender, race and ethnicity, language, or study design restrictions. Two reviewers performed the selection of studies to be analyzed. DATA EXTRACTION AND SYNTHESIS The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was followed. Data were extracted by 3 reviewers and pooled using random effects models. Hedges g effect sizes were computed. The Mixed-Methods Appraisal tool was used to assess study quality. MAIN OUTCOMES AND MEASURES Proximal outcomeswere global positive symptoms, delusions, hallucinations, and cognitive biases. Distal outcomes were self-esteem, negative symptoms, quality of life, well-being, and functioning. Immediate and sustained outcomes were examined. Meta-regressions, subgroup, and sensitivity analyses assessed moderators. RESULTS This systematic review and meta-analysis included 43 studies (46 reports). Forty reports were synthesized in meta-analysis (N=1816 participants) and 6 reports were included in narrative review. In the studies examined, MCT was associated with positive symptoms (g = 0.50; 95% CI, 0.34-0.67), delusions (g = 0.69; 95% CI, 0.45-0.93), hallucinations (g = 0.26; 95% CI, 0.11-0.40), cognitive biases (g = 0.16; 95% CI, 0.03-0.29), self-esteem (g = 0.17; 95% CI, 0.03-0.31), negative symptoms (g = 0.23; 95% CI, 0.10-0.37), and functioning (g = 0.41; 95% CI, 0.12-0.69). These associations were maintained up to 1 year. The quality of life effect size was nonsignificant (g = 0.20; 95% CI, -0.07 to 0.47); only 1 study assessed well-being. Publication year was associated with moderated hallucinations (ss = 0.04; 95% CI, 0.00-0.07). Overall, narrative review results corroborated meta-analytic findings. CONCLUSIONS AND RELEVANCE In this meta-analysis, MCT for psychosis was associated with benefits up to 1 year postintervention in several treatment contexts. These findings suggest that MCT may merit integration in treatment guidelines for schizophrenia.