Mindfulness-based interventions for non-affective psychosis: A comprehensive systematic review and meta-analysis

Aim: Although mindfulness-based interventions (MBIs) are routinely used in clinical practice, a comprehensive synthesis of the effectiveness of MBIs for non-affective psychosis has yet to be conducted. The aim in the present review and meta-analysis was to investigate the effectiveness of MBIs including those with mindfulness as an active treatment component at alleviating symptoms of psychosis to inform future clinical practice. Methods: A systematic review of studies published in journals or in dissertations in CINAHL, PubMed, EMBASE, PsycINFO, CENTRAL, ISRCTN or CNKI from January 1990 until December 2020. A total of 31 eligible studies (n=2,146) were included.Results: Effect-size estimates suggested that 22 independent samples (n=1,632) produced a statistically significant small effect for psychotic symptoms (g=-0.48), and with a clinically significant reduction of 50% from baseline (pooled OR: 1.84). Separate meta-analyses demonstrated small effects for affective symptoms (g=-0.44) and small-to-large positive effects for quality of life (g=0.38), mindfulness skills (g=0.45), and insight into illness/treatment (g=1.35). The heterogeneity was high across the studies. Conclusion: Results suggest that short-term MBIs can be beneficial for non-affective psychosis. Future research is needed to test the efficacy and safety of dedicated MBIs for this population group over a longer-term