Date of Award


Document Type


Degree Name

Master of Science in Psychology



First Reader/Committee Chair

Lewin, Michael R.


Mindfulness, purposeful attention without judgment or acceptance, and related practices are increasingly popular with a large number of people and have been incorporated into many western psychotherapies (e.g., Mindfulness-Based Stress Reduction, Dialectical Behavior Therapy, Acceptance and Commitment Therapy and Mindfulness Based Cognitive Therapy). There is considerable debate over whether mindfulness is best studied as a state, trait or procedure. Although many studies have found that trait mindfulness is related to physical and mental health outcomes, less is known about the mechanism(s) through which mindfulness enhances clinical outcomes. The current study explored the role of potential mediators of the relationship between trait mindfulness and psychological outcomes, i.e., psychological distress. Specifically, we examined whether the relationship between trait mindfulness and psychological distress is indirect, with mediators such as emotion regulation (i.e., cognitive reappraisal and emotion suppression, experiential avoidance, cognitive flexibility (i.e., alternative), and psychological inflexibility accounting for the relationship. We measured trait mindfulness, psychological distress, emotion regulation, cognitive flexibility, experiential avoidance and acceptance in a large sample of undergraduate students. We hypothesized that the relationship between trait mindfulness and psychological outcomes is indirect and may be due to enhanced acceptance, flexibility, and emotion regulation. We conducted a sequential regression, simple mediational, and multiple mediational analyses to test hypotheses. Results revealed that the proposed mediators explained additional variances in psychological distress above and beyond trait mindfulness. The simple mediational analyses indicated that individually, psychological inflexibility, emotion regulation (only cognitive reappraisal), and experiential avoidance mediated the relationship between trait mindfulness and psychological distress. Finally, the multiple mediational analysis revealed that, when tested simultaneously, only psychological inflexibility mediated the association between trait mindfulness and psychological distress. Implications of results for developing treatment packages that include mindfulness practices are discussed. Limitations of the cross-sectional design, the measurements, and definitional issues of trait mindfulness are discussed as well.