Effects of mindfulness on psychotic symptoms: insights from a randomized clinical trial

Background: to compare the effects on psychotic symptoms of six months of standard psychiatric rehabilitation versus six months of standard psychiatric rehabilitation combined with weekly mindfulness sessions. We used data from a prior exploratory clinical trial. Methods: 52 patients from a community rehabilitation center were randomly allocated to Integrated Rehabilitation Treatment (IRT) or IRT enhanced with Mindfulness Based Interventions (IRT+MBI). Measures comprised a clinical record form and the PANSS interview scored according to the five-factor model of Wallwork. Raters were blinded to treatment allocation. Results: Both groups reduced their scores in the Depression factor (IRT+MBI: F = 5.29, p = .026, N-2 = .096, IRT: F = 4.51, p = .039, N-2 = .083), IRT+MBI also reduced their scores in the Negative (F = 32.21, p < .001, N-2 = .392) and Excited (F = 4.87, p = .032, N-2 = .089) factors. Simple effect analysis at post-treatment showed significant differences in the Negative factor in favor of IRT+MBI (F = 4.67, p = .035, N-2 = .085). Conclusions: Mindfulness does not increase the frequency of positive symptoms but it does reduce negative symptoms. The lack of an effective treatment for negative psychotic symptoms underscores the clinical importance of the findings.