A randomized controlled efficacy trial of mindfulness-based stress reduction compared with an active control group and usual care for fibromyalgia: the EUDAIMON study

Abstract

Fibromyalgia (FM) syndrome represents a great challenge for clinicians and researchers because the efficacy of currently available treatments is limited. This study examined the efficacy of mindfulness-based stress reduction (MBSR) for reducing functional impairment as well as the role of mindfulness-related constructs as mediators of treatment outcomes for people with FM. Two hundred twenty-five participants with FM were randomized into 3 study arms: MBSR plus treatment-as-usual (TAU), FibroQoL (multicomponent intervention for FM) plus TAU, and TAU alone. The primary endpoint was functional impact (measured with the Fibromyalgia Impact Questionnaire Revised), and secondary outcomes included “fibromyalginess,” anxiety and depression, pain catastrophising, perceived stress, and cognitive dysfunction. The differences in outcomes between groups at post-treatment assessment (primary endpoint) and 12-month follow-up were analyzed using linear mixed-effects models and mediational models through path analyses. Mindfulness-based stress reduction was superior to TAU both at post-treatment (large effect sizes) and at follow-up (medium to large effect sizes), and MBSR was also superior to FibroQoL post-treatment (medium to large effect sizes), but in the long term, it was only modestly better (significant differences only in pain catastrophising and fibromyalginess). Immediately post-treatment, the number needed to treat for 20% improvement in MBSR vs TAU and FibroQoL was 4.0 (95% confidence interval [CI] = 2.1-6.5) and 5.0 (95% CI = 2.7-37.3). An unreliable number needed to treat value of 9 (not computable 95% CI) was found for FibroQoL vs TAU. Changes produced by MBSR in functional impact were mediated by psychological inflexibility and the mindfulness facet acting with awareness. These findings are discussed in relation to previous studies of psychological treatments for FM.

The Bed Nucleus of the Stria Terminalis as a Brain Correlate of Psychological Inflexibility in Fibromyalgia

“…This null finding accords with previous studies looking for brain structural changes after MBSR; none reported changes in BNST [12]. Unexpectedly, the effect size of the intervention on PIPS scores was smaller than expected in the present sample, as significant changes with moderate-to-large effect sizes (d = 0.70) were found in the EUDAIMON study when including the whole study sample (n = 225) [27]. Here, PIPS scores had only a small-to-moderate effect size, (d = 0.42).…”

“…Although reductions in BNST could be expected after the MBSR program, since this program promotes psychological flexibility [27], no effects were observed after the intervention. This null finding accords with previous studies looking for brain structural changes after MBSR; none reported changes in BNST [12].…”

“…Similarly, higher PF has also been found to be associated with less pain intensity and interference, less anxiety and depressive symptomatology, and improved physical and mental functioning in patients with FM [17,23,24]. Furthermore, PF (and its individual components) have also been reported to mediate clinical changes in acceptance-and mindfulness-based interventions delivered to patients with chronic pain [22,25] and FM [26][27][28].…”

“…The sample comprised 47 women [Mean age: 51.6 (SD= 7.6; range 35-64 years)] with a FM diagnosis according to the American College of Rheumatology (ACR) 1990 criteria recruited at the Rheumatology service of Parc Sanitari Sant Joan de Déu (St. Boi de Llobregat, Spain). All participants were part of the EUDAIMON project, a randomized controlled trial (RCT) on the efficacy, cost-utility and biological underpinnings of MBSR for patients with FM [27,30]. All patients were female and right-handed, and the following exclusion criteria were used: Presenting acute pain unrelated to FM on the day of the scan, having changes in medication in the last three days, presenting a body mass index (BMI) > 36 Kg/m 2 or weight > 110 Kg or other standard magnetic resonance imaging (MRI) exclusion criteria (e.g., pace-makers, metal implants), or being in litigation with the hospital.…”

“…We also examined how brain volume clusters emerging from this analysis related to other clinically relevant and third-wave cognitive variables (i.e., mindfulness and self-compassion) in FM. Finally, we also examined the effects of an intervention known to promote PF in patients with FM, namely mindfulness-based stress reduction (MBSR) [27], compared to treatment-as-usual (TAU) on PIPS-related brain volumes, in a longitudinal study performed in a subset of participants. The clinical impact of the present research is two-fold: To broaden our knowledge on the biological correlates of cognitive processes (i.e., PF) relevant for chronic pain and offer potential new brain-based biomarkers underpinning PF that could in future be targeted with psychological interventions or be useful as prognostic/predictive factors in the field of precision medicine.…”