Psychometric Properties of the Five Facets Mindfulness Questionnaire in Moderate-to-Severe, Persistent Depression

Objectives: Mindfulness has been increasingly incorporated into modern psychotherapies and healthcare services. The importance of psychometrically quantifying the construct of mindfulness has become paramount. One of the most reliable and valid instruments for the assessment of different aspects of dispositional mindfulness is the Five Facets Mindfulness Questionnaire (FFMQ). However, the psychometric properties of the FFMQ are yet to be tested in individuals with high levels of persistent depression. This study therefore investigated the psychometric properties of the FFMQ in a clinical sample with moderate-to-severe, persistent depression. Methods: The data of 187 participants recruited from a funded randomised controlled trial were utilised. Internal consistency was assessed and construct validity was examined with confirmatory factor analyses (CFA) and by statistically correlating the FFMQ to measures of depression, self-compassion, rumination and experiential avoidance. Results: Findings supported the internal consistency of the FFMQ. CFA fit indices indicated that all correlated and hierarchical models fitted the data acceptably, with results slightly favouring the correlated model. Contrary to predictions however, individual facet loadings showed that the facet Observe loaded strongly onto an overarching factor of mindfulness, whilst Nonjudge loaded marginally. Nonjudge further showed a non-significant correlation with depression. However, exploratory post hoc analysis presented findings inconsistent with CFA. Conclusions: In a sample of severely depressed individuals, psychometric investigation of the validity of the FFMQ highlighted contradictory findings relating to “Nonjudge”. Whilst such findings potentially challenge the validity of the FFMQ for use in its current structure in this sample, further investigation with a larger population is warranted. Trial Registration: ClinicalTrials.gov (NCT01047124) and the ISRCTN registry (ISRCTN10963342).