Mindfulness and its relationship with health related parameters have become a focus of interest within the health sciences. Mindfulness-based-stress reduction (MBSR) programs have generally shown efficacy for improving various medical conditions and emotional symptoms (Baer, 2003, Grossman et al., 2004 and Ott et al., 2006), although methodological variability in some studies and particularly paucity of randomized controlled trials precludes strong conclusions (Toneatto & Nguyen, 2007). Nevertheless, there is a growing body of evidence that mindfulness is particularly beneficial for coping with depression, anxiety and stress (Grossman et al., 2004 and Segal et al., 2002).
Although the concept of mindfulness was originally derived from Buddhist psychology, mindfulness can be understood in secular terms as the mental ability to focus on the direct and immediate perception of the present moment with a state of non-judgemental awareness, voluntarily suspending evaluative cognitive feedback (Hayes & Shenk, 2004).
With increasing evidence of beneficial health effects of mindfulness training, assessment of mindfulness also became desirable. To date, different scales have been developed such us (1) the Mindfulness and Attention Awareness Scale (MAAS; 15 items, 1 factor, α = .82–.87, rtt 1 = .81; Brown & Ryan, 2003), (2) theKentuckyInventoryofMindfulnessScale (KIMS; 39 items, 4 factors, α = .83–.91, rtt = .65–.86; Baer, Smith, & Allen, 2004), (3) theFiveFacetsMindfulnessQuestionnaire (FFMQ; 39 items; 1 factor, 5 facets, α = .71–.92; Baer, Smith, Hopkins, Krietemeyer, & Toney, 2006) the (4) TorontoMindfulnessScale (TMS; 39 items, 2 factors, α = .95; Lau et al., 2006), (5) theCognitiveandAffectiveMindfulnessScale, Revised (CAMS-R; 12 items, 1 factor, 4 facets, α = .74–.77; Feldman, Hayes, Kumar, Greeson, and Laurenceau, 2007), or (6) theFreiburgMindfulnessInventory (FMI; Walach, Buchheld, Buttenmüller, Kleinknecht, & Schmidt, 2006), available in a long (FMI-30, 30 items, 1 factor, α = .93−.94) and a short version (FMI-14, 14 items, 1 factor, α = .79−.86). The empirical status of these measures is comparable: all were replicated in confirmatory analysis and have seen promising external validation in different types of populations (with the exception of the CAMS-R that draws from student samples only). However, there are considerable differences concerning the definition and operationalisation of mindfulness: Whereas most inventories include several aspects of mindfulness such as awareness or an attitude of Acceptance, the MAAS focuses exclusively on the subjective experience of awareness. The KIMS and the FFMQ are based on skills as defined in Dialectical Behavior Therapy ( Welch, Rizvi, & Dimidjan, 2006). In contrast to the other inventories, the TMS measures mindfulness after meditation as a state-like construct. Finally, the FMI was developed by the help of experts of Buddhist psychology and may thus capture the essence of mindfulness more adequately ( Grossman, 2008). For that reason we confined our research to this scale.
Whereas Buchheld, Grossman, and Walach (2001) argued for four interpretable factors of the FMI-30, Walach et al. (2006) have recently presented a one-dimensional short form (FMI-14). On the other hand, Ströhle (2006) found evidence for a two-factorial solution of the short form.
As there is ambiguity concerning the factorial structure, we have decided to further investigate the psychometric properties of the FMI-14 in another validation study to clarify its factorial structure. As mindfulness-based cognitive therapy has been advocated for depression and anxiety treatment (Finucane and Mercer, 2006 and Segal et al., 2002), we sought evidence of criterion validity aspects of the scale by testing it together with a modified version of the Beck Depression Inventory (BDI-V; Schmitt, Altstötter-Gleich, Hinz, Maes, & Brähler, 2006) and the Trait-Subscale (STAI-T) of the Spielberg State-Trait Anxiety Inventory (Laux, Glanzmann, Schaffner, & Spielberger, 1981). This paper reports on the psychometric properties and factorial structure of the FMI as well as validity aspects with respect to the BDI-V and the STAI-T.
