The relationship between low levels of mindfulness skills and pathological worry: the mediating role of psychological inflexibility

Mindfulness-based interventions have recently been proposed for the treatment of generalized anxiety disorder (GAD). However, the specific nature of the relationship between mindfulness skills and pathological worry is still not very well known. This study analyzes the mediating role of psychological inflexibility-a central construct in the acceptance and commitment therapy (ACT) model of psychopathology-in the effect of mindfulness skills on pathological worry. A total of 132 nonclinical participants completed questionnaires assessing the constructs of interest: the Penn State Worry Questionnaire (PSWQ), the Acceptance and Action Questionnaire - II (AAQ-II), and the Kentucky Inventory of Mindfulness Skills (KIMS). Because the Spanish translation of the KIMS used lacked of a formal validation, its psychometric properties and factor structure were previously evaluated. This process led to a reduced version of the KIMS that showed good internal consistency and factor structure. Mediation analyses revealed that psychological inflexibility fully mediated the effects of mindfulness skills as a set on pathological worry. Regarding specific mindfulness skills, psychological inflexibility was shown to be a mediator and suppressor, respectively, of the relationship between acceptance without judgment and act with awareness on worry. Results are discussed emphasizing the need of using mindfulness exercises to promote psychological flexibility.