A systematic review and meta-analysis found a small negative association between trait mindfulness and psychotic-like experiences (PLEs) in nonclinical populations, meaning higher mindfulness levels are linked to fewer PLEs. However, mindfulness-based interventions showed no significant effect on reducing PLEs in these populations. The pooled correlation from eight studies was -0.25, and the summary effect from five intervention studies was not significant. The findings should be interpreted cautiously due to the small number of studies and high heterogeneity.
A definitive randomized controlled trial will test whether group mindfulness therapy added to treatment as usual reduces depression more than treatment as usual alone for adults with schizophrenia and persecutory delusions. The trial will recruit 144 participants across three NHS sites, randomizing them 1:1 to either group mindfulness therapy plus usual care or usual care alone. Outcomes including depression (PHQ-9) will be measured at baseline, end of therapy (about 4 months), and follow-up (about 8 months). The therapy follows a published manual. If effective and cost-effective, this group therapy could fill a gap in NICE guidelines, which currently recommend no group psychological therapies for schizophrenia.
People with persecutory delusions organize their self-concept differently than healthy individuals, holding more negative self-attributes and keeping positive and negative traits in separate mental compartments. In Study 1, 27 individuals with schizophrenia-spectrum diagnoses and current persecutory delusions showed greater compartmentalization, a higher proportion of negative attributes, and more importance assigned to negative self-aspects compared with 47 healthy controls. In Study 2, the same clinical group completed a card-sorting task before and after 12 weeks of mindfulness-based therapy or treatment-as-usual. Large effect sizes indicated reductions in compartmentalization and proportion of negative attributes following mindfulness therapy, though no link emerged between delusion severity and self-structure. The findings suggest self-structure can change with psychological therapy.