Brief Mindfulness Training for Negative Affectivity: A Systematic Review and Meta-Analysis

Objective: Over the last 10 years, there has been a dramatic increase in published randomized controlled trials (RCTs) of brief mindfulness training (from single-session inductions to multisession interventions lasting up to 2 weeks), with some preliminary indications that these training programs may improve mental health outcomes, such as negative affectivity. This meta-analysis aimed to evaluate whether brief mindfulness training reliably reduces negative affectivity. Method: PubMed, PsycINFO, and the Mind-fulness Research Monthly Newsletter were systematically searched for brief mindfulness intervention RCTs assessing negative affectivity outcomes (e.g., depression, rumination, anxiety, stress). Sixty-five RCTs, including 5,489 participants predominantly without experience in meditation (64.64% female, mean age = 24.62), qualified for the meta-analytic review. Results: The meta-analysis revealed a small but significant effect of brief mindfulness training on reducing negative affectivity compared to control programs (g = .21, p < .001). The overall effect size was significantly moderated by participant characteristics: community samples (g = .41, p < .001) produced larger training effects compared to student samples (g = .14, p = .001; Q(between) p = .03). No significant effect size differences were found between clinical and nonclinical samples. However, when accounting for publication bias, the overall effect size of brief mindfulness training programs on negative affectivity was significantly reduced (g = .04). Conclusions: Brief mindfulness training programs are increasingly popular approaches for reducing negative affectivity. This meta-analysis indicates that brief mindfulness training modestly reduces negative affectivity. Quantitative analyses indicated the presence of publication bias (i.e., unpublished null effect studies), highlighting the need to continue rigorous evaluation of brief mindfulness interventions.