A randomized trial with 130 participants tested whether the Five Facet Mindfulness Questionnaire (FFMQ) validly measures dispositional mindfulness. The study included three groups: mindfulness-based stress reduction (MBSR), an active control condition (Health Enhancement Program, HEP) that did not teach mindfulness meditation, and a waitlist control. At baseline, FFMQ facets correlated with measures of psychological symptoms and well-being, providing partial evidence for convergent validity. FFMQ scores increased for MBSR relative to the waitlist, but they also increased for HEP relative to the waitlist, and MBSR and HEP did not differ from each other. The FFMQ thus failed to show discriminant validity, raising questions about its ability to specifically measure mindfulness.
Eight weeks of mindfulness-based stress reduction (MBSR) training did not improve sustained attention or visual discrimination more than an active control program (Health Enhancement Program) in a randomized trial with 63 community adults. The study had sufficient statistical power to show that the two groups did not differ in their improvement over time on a continuous performance task. One prediction about attentional fatigue was statistically significant but uninterpretable. Some evidence for improved visual discrimination partially replicated earlier findings. Attentional sensitivity appears unaffected by MBSR, but whether mindfulness might benefit vigilance remains unclear.