Abstract
BACKGROUND: Detached Mindfulness (DM) is a central, transdiagnostic technique within Metacognitive Therapy (MCT). It involves increasing meta-awareness of intrusions while decentring from and disengaging with them, and is used to reduce the Cognitive Attentional Syndrome and dysfunctional metacognitive beliefs-key components of the metacognitive model of psychological disorders. Although DM is typically delivered within a full MCT protocol, recent research has begun to evaluate DM as a stand-alone intervention. The current study aimed to systematically review and meta-analyse its effects. METHODS: Studies were included in the systematic review if they examined DM delivered as a stand-alone intervention in clinical or non-clinical samples. Searches were carried out in PubMed, Scopus, Web of Science, and Google Scholar in May 2025. Methodological quality and risk of bias were assessed using an adapted quality appraisal checklist. Random-effects meta-analyses were conducted for clinical trials, and narrative synthesis for experimental studies. RESULTS: Fourteen studies met inclusion criteria, representing twelve independent samples exposed to DM (N = 256; all aged ≥17). Three samples evaluated DM as a stand-alone treatment in clinical trials (two in obsessive-compulsive disorder and one in panic disorder). Of the remaining nine samples, seven (one clinical, six non-clinical) examined the effects of DM on experimentally induced psychological symptoms, and two (non-clinical) on pre-existing symptoms. Across the three clinical trials, DM was associated with large symptom reductions (pooled Hedges' g for primary outcomes = -1.80, 95% CI [-2.84, -0.76]; pooled g for depressive symptoms measured as a secondary outcome = -1.15, 95% CI [-2.23, -0.08]. Of the remaining nine samples, eight reported beneficial effects of DM on at least one outcome, with significant effects typically in the medium-to-large range. CONCLUSIONS: These findings provide converging, but still limited, evidence that DM as a stand-alone intervention is associated with improvements in psychological symptoms and related processes. The results have implications for future component analyses of MCT and for the development of brief, transdiagnostic metacognitive interventions. However, there are significant limitations to the current research base including the small number of studies, methodological shortcomings, and lack of long-term follow-up; these are discussed as well as suggestions for future studies.