Examining sex as a potential moderator of metacognitive training for psychosis efficacy on cognitive insight and jumping to conclusions bias: Evidence from a large-scale harmonized database

Background: Whereas biological sex differences in psychosis are well-documented in terms of clinical presentation and illness course, their moderating role in the effectiveness of cognitive interventions remains unclear. Previous studies in first-episode psychosis (FEP) suggested sex-specific responses to Metacognitive Training for psychosis (MCT) on cognitive insight and jumping to conclusions (JTC) bias, but generalizability to broader clinical populations is unknown. Methods: This retrospective study analyzed harmonized individual participant data from 633 persons with schizophrenia spectrum disorders (SSD) who received MCT across 22 international studies. Treatment effects and potential sex moderation were analyzed using repeated-measures ANOVAs and mixed-effects logistic regression on cognitive insight (Beck Cognitive Insight Scale) and JTC bias (Cognitive Biases Questionnaire for Psychosis, JTC subscale; Beads tasks). Results: = .044) and dichotomous measures (OR = 0.592, 95% CI: 0.356-0.984). However, no significant time × sex interactions were observed for any outcome, indicating equivalent treatment benefits across sexes. Conclusions: Contrary to previous FEP-specific findings, sex does not moderate MCT efficacy in heterogeneous clinical samples including established schizophrenia. These results may support MCT implementation without sex-specific adaptations in routine clinical practice.