Decentering—the ability to observe thoughts and feelings as temporary mental events rather than as reflections of reality—may be a key mechanism through which mindfulness-based interventions reduce anxiety and depression. In a cross-sectional study of 998 adults with high emotional distress, decentering significantly mediated the link between mindfulness and lower symptoms. In a longitudinal randomized trial, 688 participants were assigned to a Mindfulness Intervention for Emotional Distress (MIED) or a waitlist control. The MIED group showed greater improvements in decentering, anxiety, and depression over time. Reciprocal influences between decentering and distress were observed, and decentering during the intervention significantly mediated the program's effect on reducing emotional distress.
Two randomized controlled trials tested whether cognitive flexibility—the ability to shift attention—explains how a mindfulness intervention reduces emotional distress. In Study 1, 607 highly distressed adults were assigned to an eight-week mindfulness program or a waitlist. In Study 2, 89 similar participants were assigned to the program or a control group. Both trials showed that the mindfulness program significantly improved anxiety, depression, and general distress. Changes in cognitive flexibility during the intervention statistically mediated later reductions in emotional distress. Specifically, shifting attention away from affective to nonaffective aspects of positive stimuli at week 5, and less shifting from negative to positive affective aspects at week 3, predicted greater distress relief at week 7. The findings indicate cognitive flexibility is a key mechanism of mindfulness-based intervention for emotional distress.