Objectives: The aim of this meta-analysis was to investigate if mindfulness is developed in some therapy or intervention programs, that are not explicitly focused on its development. Method: Randomized controlled trials were searched from Scopus database that investigated the effect of non-mindfulness-based therapy or intervention programs on the levels of mindfulness.
The search was limited to studies which have used the Five Facet Mindfulness Questionnaire for measuring mindfulness. Results: A total of 24 trials met inclusion criteria.
Among the assessed programs, two had large effects for change in mindfulness (0,8 < d), seven had medium effects (0,5 < d < 0,8), ten had small effects (0,2 < d < 0,5) and five had either no effect or negative effect (d < 0,2). The weighted mean of effect sizes of all 24 programs on mindfulness development was d = 0,41.
Conclusion: Many non-mindfulness-based therapy or intervention programs do have an effect on the increase of mindfulness.