British Journal of Health Psychology (2017), 22, 186–206 © 2016 The British Psychological Society www.wileyonlinelibrary.com Meditation awareness training for the treatment of fibromyalgia syndrome: A randomized controlled trial William Van Gordon1*, Edo Shonin1, Thomas J. Dunn2, Javier Garcia-Campayo3 and Mark D. Griffiths1 1Psychology Department, Nottingham Trent University, UK 2Psychology Division, Bishop Grosseteste University, Lincoln, UK 3Miguel Servet University Hospital, University of Zaragoza, Spain Objectives. The purpose of this study was to conduct the first randomized controlled trial (RCT) to evaluate the effectiveness of a second-generation mindfulness-based intervention (SG-MBI) for treating fibromyalgia syndrome (FMS). Compared to firstgeneration mindfulness-based interventions, SG-MBIs are more acknowledging of the spiritual aspect of mindfulness. Design. A RCT employing intent-to-treat analysis. Methods. Adults with FMS received an 8-week SG-MBI known asmeditation awareness training (MAT; n = 74) or an active control intervention known as cognitive behaviour theory for groups (n = 74). Assessments were performed at pre-, post-, and 6-month follow-up phases. Results. Meditation awareness training participants demonstrated significant and sustained improvements over control group participants in FMS symptomatology, pain perception, sleep quality, psychological distress, non-attachment (to self, symptoms, and environment), and civic engagement. Amediation analysis found that (1) civic engagement partially mediated treatment effects for all outcome variables, (2) non-attachment partially mediated treatment effects for psychological distress and sleep quality, and (3) non-attachment almost fully mediated treatment effects for FMS symptomatology and pain perception. Average daily time spent in meditation was found to be a significant predictor of changes in all outcome variables. Conclusions. Meditation awareness trainingmay be a suitable treatment for adults with FMS and appears to ameliorate FMS symptomatology and pain perception by reducing attachment to self. Statement of contribution What is already known on this subject?  Designing interventions to treat fibromyalgia syndrome (FMS) continues to be a challenge.  There is growing interest into the applications of mindfulness-based interventions for treating FMS.  Second-generation mindfulness-based interventions (SG-MBIs) are a key new direction in mindfulness research. *Correspondence should be addressed to William Van Gordon, Psychology Department, Nottingham Trent University, Nottingham NG1 4BU, UK (email: william@awaketowisdom.co.uk). DOI:10.1111/bjhp.12224 186 What does this study add?  Meditation awareness training – an SG-MBI – resulted in significant reductions in FMS symptomatology.  SG-MBIs recognize the spiritual aspect of mindfulness and may have a role in the treatment of FMS. Fibromyalgia syndrome (FMS) is a chronic pain disorder that affects approximately 3% of adults, with higher rates of occurrence in females compared to males (Branco et al., 2010). Individuals with FMS typically experience symptoms of widespread musculoskeletal pain, sleep disturbance, poor quality of life, cognitive dysfunction (particularly memory impairment), psychological distress (i.e., depression, anxiety, and stress), and fatigue (H€auser,Wolfe, T€olle, €Uceyler,& Sommer, 2012; Jones et al., 2012;Wolfe, Br€ahler, Hinz, &H€auser, 2013). The condition is also associatedwith (1) high rates of presenting at medical services (Schaefer et al., 2011), unemployment (Scott & Jones, 2014), (2) use of incapacity for work and/or disability benefits (Sicras-Mainar et al., 2009; Wolfe et al., 1997), (3) hypochondriasis, self-preoccupation, and self-attachment (Canzonieri, Pollak, Oliveira, Costa, & Natour, 2013; Van Gordon, Shonin, & Griffiths, 2016a; Wolfe, 2009), and (4) low levels of civic engagement (Van Gordon et al., 2016a). There is no reliable laboratory test for FMS, and diagnosis is often based on the exclusion of other pathologies as well as the patient's verbal responses to gentle manual pressure being applied to tender body points (Van Gordon et al., 2016a). While some patients with FMS appear to respond favourably to pharmacological treatments (principally tricyclic antidepressants and serotonin–norepinephrine reuptake inhibitors), many experience limited symptom reduction as well as adverse effects (H€auser et al., 2012; Luciano et al., 2014;N€uesch,H€auser, Bernardy, Barth,& J€uni, 2013). Consequently, an integrative treatment approach is currently preferred whereby pharmacological treatments are combined with, for example, aerobic exercise, cognitive behavioural therapy, self-help, and/or psycho-education (Van Gordon et al., 2016a). The need for more efficacious FMS treatments – including those without the side effects of pharmacotherapy – has prompted a growth of scientific investigation into the applications of mindfulness for treating FMS (Langhorst, Klose, Dobos, Bernardy, & H€auser, 2013; Modrego et al., 2016). Mindfulness derives from Buddhist practice and is concerned with focusing awareness on moment-to-moment sensory and psychological experience (Garcia-Martin et al., 2016). Thepractice is understood to increase perceptual distance from distressing sensory and psychological stimuli, and this objectification of pain helps to regulate its impact on psychosocial functioning (Morone, Lynch, Greco, Tindle, & Weiner, 2008; Van Gordon et al., 2016a). Until recently, the health care literature has predominantly focused onwhat have been termed first-generation mindfulness-based interventions (FG-MBIs). The two most empirically investigated FG-MBIs are mindfulness-based stress reduction (MBSR; KabatZinn, 1990) andmindfulness-based cognitive therapy (Segal,Williams, & Teasdale, 2002). Findings from FG-MBI studies indicate that they may have applications in the treatment of FMS. For example, a meta-analysis (n = 674) – incorporating six randomized controlled trials (RCTs) of MBSR – concluded that it led to short-term improvements in quality of life and pain compared to treatment-as-usual or active control groups (Lauche, Cramer, Dobos, Langhorst, & Schmidt, 2013). A more recent review study (n = 702; 10 RCTs, prospective or retrospective studies) that included a greater range of FG-MBIs (i.e., in addition to MBSR) reported mild-to-moderate treatment effects (Henke & Chur-Hansen, 2014). These findings are consistent with a meta-analysis (comprising nine RCTs with Meditation awareness training for treating FMS 187 active control groups) in which effect sizes in the mild-to-moderate range were reported for the effectiveness of FG-MBIs in the treatment of chronic pain (Cohen's d = .33; Goyal et al., 2014). Second-generation mindfulness-based interventions (SG-MBIs) reflect a new direction in mindfulness research and practice and have been formulated in order to address some of the limitations of FG-MBIs. SG-MBIs differ from FG-MBIs by adopting a broader definition of mindfulness that is more acknowledging of its spiritual roots. For example, an established FG-MBI definition of mindfulness was proposed by Kabat-Zinn who defined it as 'paying attention in a particular way: on purpose, in the present moment, and non-judgmentally' (1994, p. 4). This definition frames mindfulness as a predominantly attentional process and is therefore arguably less encompassing than a recently proposed SG-MBI definition in which mindfulness is deemed to be 'the process of engaging a full, direct, and active awareness of experienced phenomena that is (1) spiritual in aspect and, (2) maintained from one moment to the next' (Shonin & Van Gordon, 2015, p. 900). In addition to being overtly spiritual in nature, SG-MBIs are distinct from FG-MBIs due to them employing (1) a greater range of meditative techniques (generally delivered in a secular context), (2) ethics as a key component of the taught programme, and (3) an instructor training programme that typically requires several years of supervised mindfulness practice (Van Gordon, Shonin, & Griffiths, 2015). Some SG-MBIs also introduce participants to meditative concepts such as impermanence, interconnectedness, non-self or emptiness, and non-attachment (Shonin & Van Gordon, 2015). The introduction of the non-attachment principle is based on the Buddhist view that suffering arises as a result of an individual's 'attachment' to both themselves and external phenomena (e.g., wealth, people, and reputation; Feliu-Soler et al., 2016). The Buddhist notion of attachment has been defined as 'the over-allocation of cognitive and emotional resources towards a particular object, construct, or idea to the extent that the object is assigned an attractive quality that is unrealistic and that exceeds its intrinsic worth' (Shonin, Van Gordon, & Griffiths, 2014a, p. 126). Consequently, in the traditional meditation literature, reducing attachment (or augmenting non-attachment) is deemed to be an important feature of the path to psycho-spiritualwell-being. Furthermore, given that self-attachment is deemed to play a role in the maintenance of FMS (Van Gordon et al., 2016a), FMS interventions that specifically aim to reduce attachment (to self, symptoms, and environment) warrant empirical investigation. A positive association has been observed between spirituality and positive affect in individuals with FMS (Moreira-Almeida & Koenig, 2008). Consistent with this finding, qualitative studies of SG-MBIs have demonstrated that participants of both healthy and clinical status attribute improvements in health outcomes to increased spiritual awareness. Although a study investigating the effectiveness of an SG-MBI for treating FMS has not been conducted to date, SG-MBIs have demonstrable applications for treating many of the individual symptoms of FMS including psychological distress (Van Gordon, Shonin, Sumich, Sundin, & Griffiths, 2014), self-preoccupation and maladaptive ego-constructs (Shonin & Van Gordon, 2015; Shonin, Van Gordon, & Griffiths, 2014b), and sleep disturbance (Van Gordon, Shonin, & Griffiths, 2016b). Using these findings as a basis, the purpose of the present RCT was to address the need for a rigorous empirical assessment of the effectiveness of an SG-MBI for treating FMS. Primary outcomes were fibromyalgia symptomatology, pain perception, sleep quality, and psychological distress. Secondary outcomes were non-attachment and civic engagement. 188 William Van Gordon et al. Method Design An RCT (trial no. NCT02800720) compared meditation awareness training (MAT) with a purpose-designed active control condition. Consolidated Standards of Reporting Trials (CONSORT; Boutron, Altman, Schulz, & Ravaud, 2008; Schulz, Altman, & Moher, 2010) guidelines for non-pharmacological interventions were followed where applicable. The trialwas approvedby the research team's University Ethics Committee. A qualitative study exploring participant's experiences and general feasibilitywas embedded in the RCT, and findings from the qualitative study are reported elsewhere (see VanGordon et al., 2016a). Participants Participantsweremale and female English-speaking adultswith a current diagnosis of FMS (as confirmed by a letter from a general practitioner [GP], rheumatologist, or hospital pain consultant). Participationwas on a voluntary basis, and individualswere recruited via talks at FMS self-help groups, posters in GP surgeries, and emails sent to members of FMS support groups. Furthermore, some East Midlands GPs weremade aware of the study and were asked to informally raise awareness amongst relevant service users by suggesting that they could contact the research team for further information. As part of the informed consent process, participants were required to acknowledge that they understood that MAT (1) is deemed by its founders to be both a psychological and spiritual intervention, (2) is not intended to be a course on Buddhism (i.e., it is secular in context) but makes extensive use of Buddhist meditative techniques and principles, and (3) was founded by two Western psychologists who are also Buddhist monks. This step was implemented for ethical and transparency reasons on account of the fact that some FG-MBIs have been criticized for emphasizing or masking their affiliation with Buddhism to suit their needs (Purser, 2015). Eligibility criteria In addition to a current FMS diagnosis, the eligibility criteria for participation in the study were as follows: (1) being aged between 18 and 65 years, (2) being able to read and write using the English language, (3) not currently undergoing formal psychotherapy, (4) no changes in psychopharmacology type or dosage 1-month prior to intervention (although stable prescription medication was permitted), and (5) not currently practicing mindfulness or meditation. Participants were also required to confirm their availability to complete an 8-week intervention and 6-month follow-up assessment. Attendance at atleast seven of the eight weekly sessions is a prerequisite for course completion. In this study, participants that did not attend the requisite number of sessions were classed as having dropped out and were excluded from (or where unavailable to attend) future assessment phases. Participantswere informed about the attendance requirements via the informed consent procedure. Randomization and blinding The first author (and principal investigator) was responsible for recruitment and participant screening. Following the screening process, eligible participants were assigned five-digit pseudonyms. The document linking participant demographic data and Meditation awareness training for treating FMS 189 screening results to their pseudonyms was stored in a sealed opaque envelope in a lockable unit within the office of the principal investigator, and all other researchers were blinded as to its contents. A list of eligible participant pseudonyms, grouped by sex, was then passed to the second author who conducted the randomization procedure (the principal investigator was not involved in the randomization process). On a sex-strata basis, participant pseudonyms were placed into a bowl and then selected one at a time prior to being placed, in alternating sequence, into one of two separate envelopes corresponding to the intervention and control group (participantswere grouped by sex in order to yield sex-matched intervention and control groups). Randomization was implemented prior to administering baseline psychometric tests in order to facilitate the blinding of researchers involved in conducting the randomization procedure. Participants were blinded as to allocation condition until after completion of baseline assessments and were likewise blinded as to which allocation condition featured the target intervention. Sample size calculation Based on an equal distribution between allocation conditions, statistical power calculations using GPOWER Software (Faul & Erdinger, 1992) indicated a total sample size of 128 participants would be required for an effect size of .5, an alpha of .05, and 80% power. Consistentwith literature reviews conducted by other authors (e.g., Glombiewski et al., 2010), a comprehensive literature review conducted by the present authors found that an effect size of .5 appears to be standard for efficacy studies of mindfulness-based interventions as well as FMS treatment studies. The power calculation was conducted with the primary outcome measures in mind. An over-recruitment margin of 20 participants was applied to account for drop out. Programme description Meditation awareness training is an 8-week SG-MBI in which mindfulness is an integral component, but is not the exclusive focus (Shonin et al., 2014b;VanGordon et al., 2014). The intervention is delivered by instructorswho have undergone a 3-year supervisedMAT training programme. Participants attend eight weekly workshops (each lasting 2 hr) and receive a CD of guided meditations to facilitate daily self-practice. The weekly sessions comprise three distinct phases: (1) a taught/presentation component (approximately 45 min), (2) a facilitated group discussion component (approximately 35 min), and (3) guidedmeditation and/ormindfulness exercises (approximately 30 min). A 10-min break is scheduledprior to commencing the guidedmeditation exercises. In the third and eighth week of the programme, participants attend one-to-one support sessions (each of 50-min duration) with the programme instructor (for comprehensive information regarding the intervention protocol, see Van Gordon et al., 2014). Due to the fact that individuals with FMS can experience difficulties in concentrating (referred to as 'fibro fog'; Mease et al., 2008), in this study the intervention was slightly modified to include an additional 5-min break that occurred 45 min into the session (this was achieved by reducing the duration of the facilitated group discussion component to 30 min). In order to directly target the key symptoms and correlates of FMS, the intervention was also modified in this study to include an extended focus on: (1) mindfulness techniques specifically concerned with meditatively observing and objectifying somatic pain, (2) compassion meditation in order to help participants become less preoccupied with their illness (i.e., by becoming more aware of the suffering of others), 190 William Van Gordon et al. and (3) 'engaged mindfulness' (a technique intended to raise participants' awareness of the benefits – to both themselves and others – of contributing to thewelfare of society in a manner that does not exceed the physical and/or psychological demands of their condition). Rather than prescribe a fixed amount of daily meditation practice time, participants are encouraged to adopt a dynamic meditation routine and are guided on an individual basis to find the optimum frequency and duration of meditation sessions. According to Van Gordon et al. (2014), this avoids divisions being formed between formal seated meditation sessions and meditation during everyday life activities. In this study, MAT was delivered by the second author (30 years meditation teaching experience) and the first author provided supervision in order to identify any deviations from the standard intervention delivery format. Supervision was implemented by the first author (1) silently observing at least 15 min of each weekly session (not always following the same amount of elapsed time into the 2-hr session), and (2) engaging in discussion with the programme facilitator on a weekly basis. With the exception of the planned modifications specified above, no other deviations from the standard protocol were identified. Meditation awareness training (and the control intervention) were delivered across multiple sites in the East Midlands in separate training rooms utilized by a meditation centre andGP surgery.Other than an overheadprojector, chairs and tables, a singing bowl for use during the guidedmeditations, and sufficient space to practicewalkingmeditation (that requires participants to walk in single file), no special equipment or arrangements were required. In this study, the intervention was delivered using group sizes of approximately 25 participants. Control condition Cognitive behavioural theory for groups (CBTG) is a purpose-designed control intervention formulated by Shonin, Van Gordon, Dunn, Singh, and Griffiths (2014). CBTG is based on guidelines by MacCoon et al. (2012) for the development of suitable control groups for studies of mindfulness-based interventions (MBIs). CBTG involves educating participants in cognitive behavioural theory and principles. It is identical to the intervention condition on all non-specific factors such as overall course length, individual session duration, group and one-to-one discussion component, group size, and inclusion of an at-home practice element. Weekly sessions comprise: (1) a taught presentation component (45 min), (2) a facilitated group discussion component (30-min duration in this study), (3) guided discovery educational exercises (30 min), and (4) the same number and duration of breaks as the target intervention. The weekly sessions are explicitly education-focused and do not include any practice or discussion of meditation. To control for a facilitator effect and ensure consistency of didactic style, CBTG was delivered by the same instructor who facilitated the MAT programme. To assess for differences in the instructor's levels of enthusiasm between groups, participants in both the intervention and control groups were asked to rate (on a 1–5 Likert scale) the instructor's levels of planning and motivation. As with the target intervention, the CBTG sessions were supervised to identify any deviations from the standard intervention delivery format. With the exception of an additional 5-min break that was introduced in order tomatch the target intervention, therewere noplanned or unplannedmodifications to the delivery of CBTG. Meditation awareness training for treating FMS 191 Outcome measures Study outcomes were assessed via the following well-established psychometric scales: Revised Fibromyalgia Impact Questionnaire (FIQ-R; Bennett et al., 2009): The FIQ-R assesses the impact of FMS across the three domains of function, overall impact, and symptoms. The FIQ-R includes 21 questions that are graded on a 0–10 numeric scale and higher scores correspond to higher levels of negative impact. Questions are framed in the context of the past 7 days and include items such as 'difficulty in sitting in a chair for 45 min, 'fibromyalgia prevented me from accomplishing goals for the week', and 'please rate the level of pain'. The summed score for the function domain (range 0–90) is divided by 3, the summed score for overall impact domain (range 0–20) remains unchanged, and the summed score for the symptom domain (range 0–100) is divided by 2. The total FIQ-R score is the sum of the three modified domain scores, and the maximum total score is 100. Based on over 250 studies employing either the FIQ-R or the original Fibromyalgia Impact Questionnaire individuals diagnosed with FMS typically score between 55 and 65 (Bennett et al., 2009). Short-formMcGill Pain Questionnaire (SF-MPQ;Melzack, 1987): The Pain Perception Index of the SF-MPQ comprises 15 sensory or affective pain descriptors (e.g., throbbing, aching, heavy, and punishing) that are rated on a 4-point Likert scale (0 = none, 3 = severe). Scores for each pain descriptor are combined to give a total measure of pain perception. The maximum score is 45, and a mean improvement of more than 5 points is deemed to be clinically important (Hawker, Mian, Kendzerska, & French, 2011). Depression, Anxiety, and Stress Scale (DASS; Lovibond & Lovibond, 1995): The 21item DASS assesses psychological distress and comprises three subscales: (1) depression, (2) anxiety, and (3) stress. The scale is scored on a 4-point Likert scale (from: 0 = Did not apply to me at all, to 3 = Applied to me very much or most of the time) and features items such as 'I found it hard to wind down' and 'I felt that life was meaningless'. The DASS is completed in respect of the foregoing 7-day period. According to the DASS manual (Lovibond & Lovibond, 1995), the percentile cut-offs and corresponding mean scores for symptom severity are as follows: 0–78 (M ≤ 13) = normal, 78–87 (M = 14–18) = mild, 87–95 (M = 19–28) = moderate, and >95 (M ≥ 28 = severe). Pittsburgh Sleep Quality Index (PSQI; Buysse, Reynolds, Monk, Berman, & Kupfer, 1989): The seven-item PSQI assesses sleep quality during the past month across the domains of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. The PSQI is scored on a 4-point Likert scale (0 = no difficulty, 3 = extreme difficulty) and features items such as 'during the past month, how would you rate your sleep quality overall?' The maximum score is 21, and a global score of ≥5 indicates a poor quality of sleep (Buysse et al., 1989). Non-Attachment Scale (NAS; Sahdra, Ciarrochi, Parker, Marshall, & Heaven, 2015; Sahdra, Shaver, & Brown, 2010): The seven-item NAS is based on a Buddhist model of mental illness and evaluates the degree to which a person becomes attached to their experiences on the psychological, social, and environmental plane. The NAS also assesses the degree towhich a person is 'attached to themselves' because according to Buddhist theory, attachment to psychological or environmental phenomena arises due to a firm sense of selfhood (Van Gordon, Shonin, & Griffiths, 2016c). The NAS is constructed upon the Buddhist notion that the self does not inherently exist and that 192 William Van Gordon et al. attachment to self and environment thus constitutes a maladaptive condition (see Shonin et al. (2014a) for a discussion of the differences betweenBuddhist andWestern psychological conceptualizations of attachment). TheNAS is scored on a 6-point Likert scale (from 1 = disagree strongly to 6 = agree strongly) and features items such as 'When pleasant experiences end, I am fine moving on to what comes next'. The maximum score is 42, and higher scores reflect lower levels of attachment (or higher levels of non-attachment). Civic Engagement: Participants were asked to record how many hours during the previous 7 days they had spent engaging in paidwork, voluntarywork, participating in an event or meeting hosted by a community organization or group, and/or mentoring another non-family member of the community. Data analysis A significance level of p < .05 and two-tailed tests were employed throughout. Independent-samples t-tests (for continuous variables) and chi-square tests with Yates's correction (for categorical variables) were used to identify any significant differences between groups in demographic characteristics or baseline-dependent variable mean scores. Mixed-effects models (also known as multilevel models, random-effects model, and hierarchical models) were used to examine the effect of intervention (MAT) and control (CBTG) on all six outcome measures (i.e., FIQ-R, SF-MPQ, DASS, PSQI, NAS, and Civic Engagement). Mixed-effects modelling accounts for shared variance within-participants while modelling between-participant differences. The benefits of mixed-effects models are well-established and include reduced assumptions (i.e., homoscedasticity, sphericity, and compound symmetry) and greater statistical power over traditional methods (Baguley, 2012a; Gelman & Hill, 2007; Quene & van den Bergh, 2004; Snijders & Bosker, 1999). Furthermore, mixed-effects models adequately account for baseline differences in outcome scores bymodelling (per participant) the change in outcomemeasure relative to baseline across all measurement periods (i.e., pre-, post-, and follow-up). Prior to model estimation, distributions of all outcome variables and random-effects residuals were inspected and deemed to be close approximations of normality. Using the absolute median deviation method to detect outliers (Leys, Ley, Klein, Bernard, & Licata, 2013), no data points were deemed to be extreme in the present data set. The RCT was conducted on an 'intent-to-treat' basis with missing data at endpoint substituted using lastobservation-carried-forward basis. Results Recruitment and allocation Participant demographic characteristics are summarized in Table 1. A total of 231 individuals completed the screening questionnaire and 83 of these were screened-out on the grounds of ineligibility. The main reasons for exclusion were (1) currently receiving structured psychotherapy (32 individuals), (2) unable to confirm current diagnosis of FMS (23 individuals), (3) recent change in psychopharmacology type or dosage (13 participants), and (4) currently attending meditation or mindfulness classes (eight participants). Of the 148 remaining participants, 74 were allocated to the intervention group and the same number to the control group (see Figure 1). MAT and the control Meditation awareness training for treating FMS 193 group interventions were each delivered in three separate tranches (i.e., approximately 25 participants per tranche). Non-completion, attendance, and fidelity of implementation There were no significant differences between MAT and CBTG in the number of participants that dropped out of the study prior to completing the intervention (MAT = 20, CBTG = 22). There were no significant differences between dropout and completion samples (i.e., irrespective of allocation condition) in sex, education, employment status, marital status, and ethnicity. However, there was a significant difference for agewhere themean dropout and completer agewere 44.4 years (SD = 8.8) and 47.9 years (SD = 9.6), respectively, t(91) = 2.19, p = .03. The main reasons for non-completion were that the participant: (1) did not attend at least seven of the eight weekly sessions (MAT = 10, CBTG = 12), (2) found the intervention to be overly demanding (MAT = 6, CBTG = 6), or (3) changed medicine or commenced structured psychotherapy after baseline assessment (MAT = 3, CBTG = 2). Of those participants that attended the post-intervention assessment phase, nine MAT and 12 CBTG participants were lost to follow-up. There were no significant differences between allocation conditions in participant ratings of the instructor's levels of planning and motivation. MAT participants practiced meditation for an average of 41.11 min per day (SD = 15.26). Demographic and baseline characteristics There were no significance differences between allocation conditions in baseline demographic characteristics (i.e., sex, age, education, employment status, marital status, Table 1. Baseline demographic characteristics for each allocation condition Characteristic MAT (n = 74) CBTG (n = 74) Age, mean (SD) 46.41 (9.06) 47.34 (9.83) Female (%) 82.4 83.8 Employed (%) 52.70 48.65 Education (%) School leaver 55.41 59.46 Vocational 25.68 25.68 University 18.92 14.87 Marital status (%) Married 56.76 63.51 Single 9.46 5.41 Divorced 27.03 24.32 Widow 6.76 6.76 Ethnicity (%) White (British) 77.03 71.62 White (Non-British) 9.46 9.46 Asian 8.11 9.46 Black (Caribbean) 5.3 9.46 Note. CBTG = Cognitive behavioural theory for groups; MAT = meditation awareness training. 194 William Van Gordon et al. or ethnicity). Likewise, therewere no significant differences betweenMAT and the CBTG group in baseline scores on each of the six outcome measures. Analysis of outcome measures A separate mixed-effects model was estimated for each outcomemeasure (see Table 2 for means and SDs). Each model included Group (control, intervention) and measurement Interval (pre-, post-, follow-up) as fixed effects (i.e., in the form of an interaction predictor [Group*Interval]) and Participant (within measurement Interval) as a random effect. This allowed a unique regression model (i.e., intercept and slope) to be specified for every participant across measurement intervals (see Figure S1 for an exemplar modelling DASS scores across measurement intervals). Results from the six estimated mixed-effects models show an overall strong effect of intervention compared to control for all outcome measures (see Table 3 for summaries of each model). More specifically, relative to baseline and compared to control, intervention resulted in a (1) 6.24 (at post) and 7.92 (at follow-up) greater decrease in FIQ-R score, (2) 2.01 (at post) and 3.01 (at follow-up) greater decrease in SF-MPQ score, (3) 3.70 (at post) and 4.86 (at follow-up) greater decrease in DASS score, (4) 1.50 (at post) and 2.28 (at follow-up) greater decrease in PSQI score, (5) 2.81 (at post) and 3.57 (at follow-up) greater increase in NAS score, and (6) 1.69 (at post) and 2.05 (at follow-up) greater increase in Civic Engagement (see Figure S2 for a breakdown of intervention and control group outcome means across measurement intervals).Overall, results demonstrate thatMAT significantly outperformedCBTGat both postand follow-up assessment phases for all six outcome measures. Expressed an interest and completed screening forms n = 231 Randomization n = 148 Excluded n = 83 Intervention group n = 74 Withdrew n = 22 Control group n = 74 Withdrew n = 20 Completed post-intervention assessment n = 54 Completed post-intervention assessment n = 52 Completed follow-up assessment n = 45 Completed follow-up assessment n = 40 Figure 1. Flow of participants through recruitment and assessment phases. Meditation awareness training for treating FMS 195 T a b le 2 . M e an s an d st an d ar d d e vi at io n s o f o u tc o m e va ri ab le sc o re s fo r gr o u p an d ti m e G ro u p FI Q -R SF -M P Q D A SS P SQ I N A S C iv ic e n ga ge m e n t M e an SD M e an SD M e an SD M e an SD M e an SD M e an SD P re In te rv e n ti o n 5 5 .2 4 1 0 .0 6 2 8 .0 4 4 .6 4 2 6 .6 1 5 .3 3 1 4 .1 1 2 .4 3 1 8 .4 5 4 .1 1 1 7 .2 4 1 1 .6 2 C o n tr o l 5 4 .0 4 8 .8 6 2 7 .5 8 3 .6 9 2 6 .2 4 4 .1 9 1 4 .0 9 2 .3 5 1 8 .2 8 3 .7 0 1 7 .7 8 1 2 .2 3 P o st In te rv e n ti o n 4 6 .8 9 9 .5 5 2 4 .8 2 4 .5 6 2 1 .8 2 5 .0 2 1 1 .9 1 2 .7 1 2 2 .1 4 4 .6 8 1 9 .3 5 1 1 .9 5 C o n tr o l 5 1 .9 3 8 .8 0 2 6 .3 8 3 .7 5 2 5 .1 6 4 .1 1 1 3 .3 9 2 .5 3 1 9 .1 6 3 .9 2 1 8 .2 0 1 1 .8 3 Fo llo w -u p In te rv e n ti o n 4 5 .6 5 1 0 .9 5 2 3 .8 4 5 .3 8 2 0 .6 5 5 .9 6 1 1 .3 6 3 .0 9 2 2 .7 8 5 .3 9 1 9 .8 5 1 1 .8 0 C o n tr o l 5 2 .3 6 9 .2 9 2 6 .3 9 3 .9 3 2 5 .1 5 4 .5 8 1 3 .6 4 2 .5 5 1 9 .0 5 3 .7 8 1 8 .3 4 1 2 .2 3 N ot e. D A SS = D e p re ss io n , A n x ie ty , an d St re ss Sc al e ; FI Q -R = R e vi se d Fi b ro m ya lg ia Im p ac t Q u e st io n n ai re ; N A S = N o n -A tt ac h m e n t Sc al e ; P SQ I = P it ts b u rg h Sl e e p Q u al it y In d e x ;S FM P Q = Sh o rt -f o rm M cG ill P ai n Q u e st io n n ai re . 196 William Van Gordon et al. Intervention engagement effects A linear model was estimated, regressing the number of minutes meditated per day onto the difference between baseline and follow-up for each outcome measure. Results showed significant linear relationships between the number of minutes meditated and all outcome differences (see Table 4). This suggests that the level of engagement with meditation is a good indicator of its effect, as captured by six different outcomemeasures. Mediation analysis Severalmodelswere estimated to test themediating effects of the two secondary outcome variables (Civic Engagement, NAS) on all primary outcome variables (FIQ-R, SF-MPQ, DASS, PSQI). Given the established relationships between IV-DV and IV-M (i.e., paths a and c of Figure S3) via the mixed-effects models (see Table 3), only path bwas inspected for a correlationbetweenmediator andDV (Baron&Kenny, 1986). Analysis demonstrated significant relationships between each mediator and respective outcome measure (see Table 3. Fixed-effects estimates (at postand follow-up assessment phases) with 95% CIs for all six outcome measures Value CIs t-Value p-Value FIQ-R (Intercept) 54.04 Post 6.24 8.24 to 4.25 6.13 <.001 Follow-up 7.92 13.76 to 7.76 6.14 <.001 SF-MPQ (Intercept) 27.58 Post 2.01 2.80 to 1.26 5.24 <.001 Follow-up 3.01 4.09 to 1.94 5.48 <.001 DASS (Intercept) 26.24 Post 3.70 4.77 to 2.63 6.80 <.001 Follow-up 4.86 6.30 to 3.43 6.63 <.001 PSQI (Intercept) 14.09 Post 1.50 2.03 to 0.96 5.53 <.001 Follow-up 2.28 2.94 to 1.63 6.83 <.001 NAS (Intercept) 18.28 Post 2.81 1.92 to 3.70 6.17 <.001 Follow-up 3.57 2.50 to 4.63 6.56 <.001 Civic engagement (Intercept) 17.78 Post 1.69 0.53 to 2.84 2.86 <.01 Follow-up 2.05 1.10 to 3.00 4.24 <.001 Note. DASS = Depression, Anxiety, and Stress Scale; FIQ-R = Revised Fibromyalgia Impact Questionnaire; NAS = Non-Attachment Scale; PSQI = Pittsburgh Sleep Quality Index; SF-MPQ = Short-form McGill Pain Questionnaire. The reference category in all cases is the control group. This means a Post-FIQ-R score of6.24 can be interpreted as a 6.24 change in FIQ-R score in comparison with the control condition relative to baseline (i.e., Pre-FIQ-R score). Meditation awareness training for treating FMS 197 Table 5). Having established that all variables were correlated, a comparison between the direct (path c) and indirect effects (paths c + b)was undertaken to determinewhether the relationship between the IV and DV was attenuated by the inclusion of a mediator (M). The results showed that Civic Engagement was a partial mediator of treatment effects across all outcome measures (FIQ-R, SF-MPQ, DASS, PSQI). This can be seen in Table 6 where each IV-DV regression coefficient is reduced (but remains statistically significant) whenCivic Engagement is introduced into themodel. TreatingNAS as amediator resulted in partialmediation of treatment effects for DASS and PSQI but close to full mediation (i.e., IV-DV paths became non-significant with the inclusion of M) for FIQ-R and SF-MPQ (see Table 6). This suggests that non-attachment to the self and environment is an important mediating mechanism in reducing fibromyalgia symptoms. Discussion In the present study, an RCT compared MAT with a purpose-designed control intervention in individuals with FMS. MAT participants demonstrated significant Table 5. Parameter estimates of path b treating the potential mediator as a predictor of each outcome measure Intercept Estimate SE t-Value p-Value Civic engagement FIQ-R 2.66 1.87 0.17 10.80 <.001 SF-MPQ 1.55 0.72 0.07 9.44 <.001 DASS 1.85 1.06 0.10 10.35 <.001 PSQI 0.93 0.42 0.05 8.33 <.001 NAS FIQ-R 0.27 2.10 0.08 24.60 <.001 SF-MPQ 0.69 0.78 0.04 16.30 <.001 DASS 0.58 1.15 0.05 19.62 <.001 PSQI 0.30 0.50 0.02 17.11 <.001 Note. DASS = Depression, Anxiety, and Stress Scale; FIQ-R = Revised Fibromyalgia Impact Questionnaire; NAS = Non-Attachment Scale; PSQI = Pittsburgh Sleep Quality Index; SF-MPQ = Short-form McGill Pain Questionnaire. Table 4. Parameter estimates of linear models for minutes meditated and outcome measures Outcome measures Intercept Estimate SE t-Value p-Value FIQ-R 7.59 0.50 0.06 8.05 <.001 SF-MPQ 0.82 0.16 0.03 5.53 <.001 DASS 3.17 0.28 0.03 8.28 <.001 PSQI 0.72 0.11 0.02 6.71 <.001 NAS 2.87 0.21 0.02 9.20 <.001 Civic engagement 0.05 0.09 0.03 2.59 <.05 Note. DASS = Depression, Anxiety, and Stress Scale; FIQ-R = Revised Fibromyalgia Impact Questionnaire; NAS = Non-Attachment Scale; PSQI = Pittsburgh Sleep Quality Index; SF-MPQ = Short-form McGill Pain Questionnaire. All outcome measure differences (baseline – follow-up) are predicted by the number of average minutes meditated per day. 198 William Van Gordon et al. T a b le 6 . P ar am e te r e st im at e s fo r m e d ia ti o n m o d e ls w it h ci vi c e n ga ge m e n t an d N A S as se p ar at e m e d ia to rs o fa ll p ri m ar y o u tc o m e va ri ab le s (F IQ -R ,S FM P Q ,D A SS , P SQ I) FI Q -R SF -M P Q D A SS P SQ I St e p 1 St e p 2 St e p 1 St e p 2 St e p 1 St e p 2 St e p 1 St e p 2 In te rc e p t 1 .6 7 0 .7 7 1 .1 9 0 .8 4 1 .0 9 0 .5 9 0 .4 5 0 .2 7 b (I V ) 7 .9 2 ** * 4 .5 6 ** * 3 .0 1 ** * 1 .7 1 ** * 4 .8 6 ** * 3 .0 1 ** * 2 .2 8 ** * 1 .5 8 ** * b (c iv ic e n g. ) 1 .6 3 ** * 0 .6 3 ** * 0 .8 9 ** * 0 .3 3 ** * F ch an ge 8 7 .8 4 ** * 6 5 .4 4 ** * 7 9 .1 8 ** * 4 6 .4 9 ** * R 2 .2 1 .5 1 .1 7 .4 2 .2 3 .5 0 .2 4 .4 2 In te rc e p t 1 .6 7 0 .0 8 1 .1 8 0 .5 9 1 .0 9 0 .2 5 0 .4 5 0 .0 9 b (I V ) 7 .9 1 ** * 0 .5 5 3 .0 1 ** * 0 .2 7 4 .8 6 ** * 0 .9 7 * 2 .2 8 ** * 0 .6 1 * b (N A S) 2 .0 6 ** * 0 .7 6 ** * 1 .0 8 ** * 0 .4 6 ** * F ch an ge 4 5 0 .5 0 ** * 1 9 5 .4 2 ** * 2 7 1 .2 1 ** * 1 9 9 .3 ** * R 2 .2 0 .8 0 .1 7 .6 4 .2 3 .7 3 .2 4 .6 8 N ot e. D A SS = D e p re ss io n , A n x ie ty , an d St re ss Sc al e ; FI Q -R = R e vi se d Fi b ro m ya lg ia Im p ac t Q u e st io n n ai re ; N A S = N o n -A tt ac h m e n t Sc al e ; P SQ I = P it ts b u rg h Sl e e p Q u al it y In d e x ;S FM P Q = Sh o rt -f o rm M cG ill P ai n Q u e st io n n ai re . St e p 1 = d ir e ct e ff e ct (D V ~I V ), St e p 2 = in d ir e ct e ff e ct (D V ~I V + M ) [' ~' = p re d ic te d b y] . Si g. le ve l: ** *. 0 0 1 ,* .0 5 . Meditation awareness training for treating FMS 199 improvements over control group participants in levels of FMS symptomatology, pain perception, sleep quality, psychological distress, non-attachment, and civic engagement. The therapeutic gains attributed to MAT were maintained (and in some cases slightly augmented) at 6-month follow-up. Approximately one in four MAT participants did not complete the intervention. This level of non-completion is consistent with other studies administering meditation-based interventions to individuals with FMSwhere non-completion rates between 21% and 37% have been reported (e.g., Kaplan, Goldenberg, & Galvin-Nadeau, 1993; Mannerkorpi & Arndorw, 2004; Weissbecker et al., 2004). However, in the present study, only six participants reported that they dropped out because the intervention was overdemanding. A more common reason for non-completion was failure to attend at least seven of the eight weekly MAT sessions (i.e., 10 participants reported that they were unable to attend one ormore sessions due to unforeseen circumstances). Given that some studies investigating the applications of mindfulness for treating FMS have set the requisite attendance rate as low as 50% (e.g., Grossman, Schwarzer, Jena, Naumann, and Walach (2011), and given that FMS treatment studies typically report relatively high rates of dropout (i.e., when compared to other patient groups), the present authors deem that the non-completion levels observed here support the acceptability of MAT for the target population (i.e., an equivalent level of dropout observed in an intervention with higher attendance requirements suggests that it is relatively more acceptable). Additional support for the acceptability of the intervention is derived from the fact that no significant differences in drop out were observed across allocation conditions. With the exception ofmeditative practices andprinciples, theCBTGcontrol condition was designed to replicate MAT on all other intervention design factors (e.g., duration, facilitator–participant contact time, group discussion, and instructor didactic style). Compared to a wait list control, treatment-as-usual, or 'convenience' comparison intervention, the use of a 'matched' active control condition allows therapeutic gains due to non-specific factors (e.g., group interaction and therapeutic alliance) to be filtered out. Consequently, findings from the present study provide a reliable indicator of the treatment effects that can be attributed to the 'active ingredient' ofMAT (i.e., meditation). The fact that therapeutic improvements were due to meditation is further supported by findings from the regression analysis that showed average daily time spendmeditatingwas a significant predictor of changes in all outcome variables. Designing studies that permit such inferences to be made is particularly important for MBIs because such interventions typically employ a variety of therapeutic and relaxation techniques. Irrespective of allocation condition, a slight but statistically significant age difference was observed in the present study between completers and non-completers. The fact that non-completers were slightly older that completers (mean age of 47.9 and 44.4 years, respectively) could suggest that the acceptability of both MAT and CBTG is reduced in slightly older FMS populations. However, both the age difference and non-completion sample size are too small to draw reliable conclusions in this respect. Furthermore, this finding has not been observed in other studies of MAT or – to the best of the present authors' knowledge – in other MBI studies involving individuals with FMS. Nevertheless, future FMS treatment studies using MBIs could seek to investigate this finding further. The improvements experienced by participants across all primary outcome measures (i.e., fibromyalgia symptomatology, pain perception, psychological distress, and sleep quality) are largely consistent with FG-MBI studies involving individuals with FMS (e.g., Davis & Zautra, 2013; Henke &Chur-Hansen, 2014; Lauche et al., 2013). However, based on a single SG-MBI study, it is difficult to draw reliable conclusions as to the comparative 200 William Van Gordon et al. effectiveness of SG-MBIs and FG-MBIs for individuals with FMS. Reliably formulating such conclusions would require further controlled large-sample FMS treatment studies using SG-MBIs and/or several purpose designed head-to-head studies. Data on which particular MBI is most effective for FMS (or a given medical illness) are certainly of value to the medical community. However, rather than seek to outperform or replace FG-MBIs, the primary intent underlying the SG-MBI initiative appears to be that of providing service userswith a greater choice of evidence-basedmindfulness intervention – including that of practicing mindfulness in a manner that is more consistent with the traditional spiritual conceptualization of the technique (Van Gordon, Shonin, Lomas, & Griffiths, 2016). Notwithstanding the consistency between findings from primary outcome measures in the present study and those from FMS treatment studies using FG-MBIs, a qualitative feasibility study that was embedded within the present RCT (i.e., Van Gordon et al., 2016a) reported outcomes that are not typically associated with FG-MBIs. More specifically, analysis of interview transcripts from 10 MAT participants that were randomly allocated to a qualitative arm yielded a master theme of spiritual growth. This theme is consistent with outcomes from the mediation analysis which showed that nonattachment to self almost fully mediated the treatment effects for FMS symptomatology and pain perception. In Buddhism, 'spiritual growth' and 'reductions in attachment' are arguably synonymous terms because according to the Buddhist conceptualization, a practice can be deemed spiritual if it helps to transcend 'selfhood' (Van Gordon, Shonin, Lomas, et al., 2016). The above-mentioned qualitative study also reported a theme of increased willingness to civically engage that participants attributed to greater spiritual awareness as well as a reduced emphasis on their own suffering and life problems (Van Gordon et al., 2016a). This is consistent with the finding in the current study of civic engagement partially meditating the treatment effects for all outcome variables. Being more 'other-centred' improves life perspective and dismantles self-obsessed and self-disparaging cognitive schemas (Shonin, Van Gordon, Compare, Zangeneh, & Griffiths, 2015). Furthermore, a compassionate disposition and spiritual outlook has been shown to increase socialconnectedness and prosocial behaviour (Hutcherson, Seppala, & Gross, 2008; Leiberg, Klimecki, & Singer, 2011). Thus, viewing the findings of this and the embedded qualitative study as a collective, it seems reasonable to conclude that ameditation-induced growth in spirituality played an important mechanistic role in improving both primary and secondary outcomes. Key limitations of the study were reliance on self-report measures and the fact that outcomeswere only assessed at three timepoints (i.e., pre-, post-, and6-month follow-up). A greater number of assessment phaseswould provide insights onwhich particular stages of the 8-week intervention have the strongest treatment effects. Furthermore, an assessment beyond the 6-month stage would provide a better indication of maintenance effects as well as the need for booster sessions. A further factor that may limit findings is a phenomenon that has been termed the 'popularity effect' (Shonin, Van Gordon, & Griffiths, 2015). Mindfulness and meditation are experiencing growing popularity amongst both the scientific community and general public. Consequently, outcomes of both FG-MBI and SG-MBI studies could be influenced by participants' belief that they are receiving a 'fashionable' and/or 'proven' psychotherapeutic technique (Shonin, Van Gordon,&Griffiths, 2015). This is a difficult confounding factor to control for because it is almost impossible to blind participants from the fact they are undergoing mindfulness training. Finally, althoughGPs and other health professionals assisted in raising awareness of the study, interested participantswere required to contact the research teamdirectly in Meditation awareness training for treating FMS 201 order to be considered for recruitment. Thus, participants in the present study were effectively 'self-referring' and it is difficult to gauge whether outcomes would be as favourable for individuals directly referred by their GP or another health professional. The present study suggests that MAT is an effective FMS treatment and contributes further evidence supporting the applications of SG-MBIs in clinical and other applied settings. A considerable focus on the 'self' by some individuals with FMS means that SGMBIs (that place emphasis on reducing attachment to self) may be particularly suitable treatments for this population group. Further controlled empirical studies using large sample sizes are therefore warranted. Author contributions We confirm that all authors of this article had access to the study data, are responsible for all contents of the article, and had authority overmanuscript preparation and the decision to submit the manuscript for publication. Funding sources No financial support was received for this study. Ethical compliance The study received ethical approval from the ethics committee of Nottingham Trent University College of Business Law and Social Sciences. Conflict of interest All authors declare no conflict of interest. References Baguley, T. (2012a). Serious stats: A guide to advanced statistics for the behavioral sciences. Basingstoke, UK: Palgrave Macmillan. Baguley, T. (2012b). Calculating and graphing within-subject confidence intervals for ANOVA. Behavior Research Methods, 44, 158–175. doi:10.3758/s13428-011-0123-7 Baron, R., & Kenny, D. (1986). The moderator–mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182. doi:10.1037/0022-3514.51.6.1173 Bennett, R. M., Friend, R., Jones, K. D., Ward, R., Han, B. K., & Ross, R. L. (2009). The Revised Fibromyalgia Impact Questionnaire (FIQR): Validation and psychometric properties. Arthritis Research and Therapy, 11, R120. doi:10.1186/ar2783 Boutron, I., Altman, D. G., Schulz, K. F., & Ravaud, P. (2008). Extending the CONSORT statement to randomized trials of nonpharmacologic treatment: Explanation and elaboration. Annals of Internal Medicine, 148, 295–309. doi:10.7326/0003-4819-148-4-200802190-00008 Branco, J. C., Bannwarth, B., Failde, I., Abello Carbonell, J., Blotman, F., Spaeth, M., . . . MatucciCerinic, M. (2010). Prevalence of fibromyalgia: A survey in five European countries. Seminars in Arthritis and Rheumatism, 39, 448–455. doi:10.1016/j.semarthrit.2008.12.003 Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R., &Kupfer, D. J. (1989). The Pittsburgh Sleep Quality Index (PSQI): A new instrument for psychiatric research and practice. Psychiatry Research, 28, 193–213. doi:10.1016/0165-1781(89)90047-4 202 William Van Gordon et al. Canzonieri, A. M., Pollak, D. F., Oliveira, P. J., Costa, M. E., & Natour, J. (2013). Evaluation of sociodemographic variables, psychiatric comorbidity, andpain in fibromyalgia patients.Annals of the Rheumatic Diseases, 71, 756. doi:10.1136/annrheumdis-2012-eular.1418 Davis, M. C., & Zautra, A. J. (2013). An online mindfulness intervention targeting socioemotional regulation in fibromyalgia: Results of a randomized controlled trial. Annals of Behavioral Medicine, 46, 273–284. doi:10.1007/s12160-013-9513-7 Faul, F., & Erdinger, E. (1992). GPOWER: A priori, post-hoc, and compromise power analysis for MS-DOS. Bonn, Germany: Bonn University. Feliu-Soler, A., Soler, J., Luciano, J. V., Cebolla, A., Elices, M., Demarzo, M., & Garcıa-Campayo, J. (2016). Psychometric properties of the Spanish version of the Non-Attachment Scale (NAS) and its relationship with mindfulness, decentering and mental health. Mindfulness, 7, 1156–1169. doi:10.2196/jmir.6.3.e29 Garcia-Martin, E., Ruiz-de-Gopegui, E., Otin, S., Blasco, A., Larrosa, J. M., Polo, V., . . . GarciaCampayo, J. (2016). Assessment of visual function and structural retinal changes in zen meditators: Potential effect of mindfulness on visual ability. Mindfulness, 7, 979–987. doi:10.1007/s12671-016-0537-5 Gelman, A., & Hill, J. (2007). Data analysis using regression and multilevel/hierarchical model. Cambridge, UK: Cambridge University Press. Glombiewski, J. A., Sawyer, A. T., Gutermann, J., Koenig, K., Rief, W., & Hofmann, S. G. (2010). Psychological treatments for fibromyalgia: A meta-analysis. Pain, 151, 280–295. doi:10.1016/ j.pain.2010.06.011 Goyal, M., Singh, S., Sibinga, E. M., Gould, N. F., Rowland-Seymour, A., Sharma, R., . . . Haythornthwaite, J. A. (2014). Meditation programs for psychological stress and well-being: A systematic review and meta-analysis. JAMA Internal Medicine, 174, 357–368. doi:10.1016/ j.pain.2010.06.011a Grossman, P., Schwarzer, B., Jena, S., Naumann, J., &Walach, H. (2011). Treating fibromyalgia with mindfulness-based stress reduction: Results from a 3-armed randomized controlled trial. Pain, 152, 361–369. doi:10.1016/j.pain.2010.10.043 H€auser,W.,Wolfe, F., T€olle, T., €Uceyler, N., & Sommer, C. (2012). The role of antidepressants in the management of fibromyalgia syndrome: A systematic review and meta-analysis. CNS Drugs, 26, 297–307. doi:10.2165/11598970 Hawker, G. A., Mian, S., Kendzerska, T., & French, M. (2011). Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care and Research, 63, S240–S252. doi:10.1002/ acr.20543 Henke, M., & Chur-Hansen, A. (2014). The effectiveness ofmindfulness-based programs on physical symptoms and psychological distress in patients with fibromyalgia: A systematic review. International Journal of Wellbeing, 4, 28–45. doi:10.5502/ijw.v4i1.2 Hutcherson, C. A., Seppala, E. M., & Gross, J. J. (2008). Loving-kindness meditation increases social connectedness. Emotion, 8, 720–724. doi:10.1037/a0013237 Jones, K. D., Sherman, C. A., Mist, S. D., Carson, J. W., Bennett, R. M., & Li, F. (2012). A randomized controlled trial of 8-form Tai chi improves symptoms and functional mobility in fibromyalgia patients. Clinical Rheumatology, 31, 1205–1214. doi:10.1007/s10067-012-1996-2 Kabat-Zinn, J. (1990). Full catastrophe living: Using the wisdom of your body and mind to face stress, pain and illness. New York, NY: Delacourt. Kabat-Zinn, J. (1994). Wherever you go, there you are: Mindfulness meditation in everyday life. New York, NY: Hyperion. Kaplan, K. H., Goldenberg, D. L., & Galvin-Nadeau, M. (1993). The impact of a meditation-based stress reduction program on fibromyalgia. General Hospital Psychiatry, 15, 284–289. doi:10.1037/1072-5245.12.2.164 Meditation awareness training for treating FMS 203 Langhorst, J., Klose, P., Dobos, G. J., Bernardy, K., & H€auser, W. (2013). Efficacy and safety of meditative movement therapies in fibromyalgia syndrome: A systematic review and metaanalysis of randomized controlled trials. Rheumatology International, 33, 193–207. doi:10.1007/s00296-012-2360-1 Lauche, R., Cramer, H., Dobos, G., Langhorst, J., & Schmidt, S. (2013). A systematic review andmetaanalysis of mindfulness-based stress reduction for the fibromyalgia syndrome. Journal of Psychosomatic Research, 75, 500–510. doi:10.1016/j.jpsychores.2013.10.010 Leiberg, S., Klimecki, O., & Singer, T. (2011). Short-term compassion training increases prosocial behavior in a newly developed prosocial game. PLoS ONE, 6, e17798. doi:10.1371/journal. pone.0017798 Leys, C., Ley, C., Klein, O., Bernard, P., & Licata, L. (2013). Detecting outliers: Do not use standard deviation around themean, use absolute deviation around themedian. Journal of Experimental Social Psychology, 49, 764–766. doi:10.1016/j.jesp.2013.03.013 Lovibond, S. H., & Lovibond, P. F. (1995).Manual for the depression anxiety stress scales. Sydney, Australia: Psychology Foundation. Luciano, J. V., Guallar, J. A., Aguado, J., Lopez-del-Hoyo, Y., Olivan, B., Magallon, R., . . . GarciaCampayo, J. (2014). Effectiveness of group acceptance and commitment therapy for fibromyalgia: A 6-month randomized controlled trial (EFFIGACT study). Pain, 155, 693–702. doi:10.1016/j.pain.2013.12.029 MacCoon, D. G., Imel, Z. E., Rosenkranz, M. A., Sheftel, J. G., Weng, H. Y., Sullivan, J. C., . . . Lutz, A. (2012). The validation of an active control intervention for Mindfulness Based Stress Reduction (MBSR). Behaviour Research and Therapy, 50, 3–12. doi:10.1016/j.brat.2011.10.011 Mannerkorpi, K., & Arndorw, M. (2004). Efficacy and feasibility of a combination of body awareness therapy and qigong in patients with fibromyalgia: A pilot study. Journal of Rehabilitation Medicine, 36, 279–281. doi:10.1177/0898010110385939 Mease, P. J., Arnold, L. M., Crofford, L. J., Williams, D. A., Russell, I. J., Humphrey, L., . . .Martin, S. A. (2008). Identifying the clinical domains of fibromyalgia: Contributions fromclinician andpatient delphi exercises. Arthritis Care and Research, 59, 952–960. doi:10.1002/art.23826 Melzack, R. (1987). The Short-form McGill Pain Questionnaire. Pain, 30, 191–197. doi:10.1016/ 0304-3959(87)91074-8 Modrego, M., Morillo, H., Lopez Montoyo, A., Correa, M., Borao, L., & Garcıa-Campayo, J. (2016). Mindfulness levels in patients with fibromyalgia following recommended pharmacological treatment: A multicenter, uncontrolled, one-year follow-up study. Mindfulness and Compassion, 1, 13–21. Moreira-Almeida, A., & Koenig, H. G. (2008). Religiousness and spirituality in fibromyalgia and chronic pain patients. Current Pain andHeadache Reports, 12, 327–332. doi:10.1007/s11916008-0055-9 Morone, N. E., Lynch, C. S., Greco, C. M., Tindle, H. A., & Weiner, D. K. (2008). "I felt like a new person". The effects of mindfulness meditation on older adults with chronic pain: Qualitative narrative analysis of diary entries. The Journal of Pain, 9, 841–848. doi:10.1016/ j.jpain.2008.04.003 N€uesch, E., H€auser, W., Bernardy, K., Barth, J., & J€uni, P. (2013). Comparative efficacy of pharmacological and non-pharmacological interventions in fibromyalgia syndrome: Network meta-analysis. Annals of the Rheumatic Diseases, 72, 955–962. doi:10.1136/annrheumdis2011-201249 Purser, R. E. (2015). Clearing the muddled path of traditional and contemporary mindfulness: A response to Monteiro, Musten, and Compson.Mindfulness, 6, 23–45. doi:10.1007/s12671-0140373-4 Quene, H., & van den Bergh, H. (2004). On multi-level modelling of data from repeated measures designs: A tutorial. Speech Communication, 43, 103–121. doi:10.1016/j.wocn.2010.08.001 Sahdra, B. K., Ciarrochi, J., Parker, P. D., Marshall, S., & Heaven, P. (2015). Empathy and nonattachment independently predict peer nominations of prosocial behavior of adolescents. Frontiers in Psychology, 6, 263. doi:10.1080/00223890903425960 204 William Van Gordon et al. Sahdra, B. K., Shaver, P. R., & Brown, K. W. (2010). A scale to measure non-attachment: A Buddhist complement to Western research on attachment and adaptive functioning. Journal of Personality Assessment, 92, 116–127. doi:10.3389/fpsyg.2015.00263 Schaefer, C., Chandran, A., Hufstader, M., Baik, R., McNett, M., Goldenberg, D., . . . Zlateva, G. (2011). The comparative burdenofmild,moderate and severe fibromyalgia: Results froma crosssectional survey in the United States.Health Quality of Life Outcomes, 9, 71. doi:10.1186/14777525-9-71 Schulz, K. F., Altman, D. G., &Moher, D. (2010). CONSORT 2010 statement: Updated guidelines for reporting parallel group randomized trials.Annals of InternalMedicine, 152, 1–8. doi:10.1136/ bmj.c332 Scott, M., & Jones, K. (2014). Mindfulness in a fibromyalgia population. The Journal of Alternative and Complementary Medicine, 20, A94–A95. doi:10.1089/acm.2014.5249.abstract Segal, Z. V., Williams, J. M., & Teasdale, J. D. (2002). Mindfulness-based cognitive therapy for depression: A new approach to preventing relapse. New York, NY: Guilford. Shonin, E., & Van Gordon, W. (2015). Managers' experiences of Meditation Awareness Training. Mindfulness, 4, 899–909. doi:10.1007/s12671-014-0334-y Shonin, E., Van Gordon,W., Compare, A., Zangeneh, M., & Griffiths, M. D. (2015). Buddhist-derived loving-kindness and compassionmeditation for the treatment of psychopathology: A systematic review. Mindfulness, 6, 1161–1180. doi:10.1007/s12671-014-0368-1 Shonin, E., Van Gordon, W., Dunn, T., Singh, N., & Griffiths, M. D. (2014). Meditation Awareness Training for work-related wellbeing and job performance: A randomized controlled trial. International Journal ofMental Health andAddiction, 12, 806–823. doi:10.1007/s11469-0149513-2 Shonin, E., Van Gordon, W., & Griffiths, M. D. (2014a). The emerging role of Buddhism in clinical psychology: Toward effective integration. Psychology of Religion and Spirituality, 6, 123–137. doi:10.1037/a0035859 Shonin, E., Van Gordon, W., & Griffiths, M. D. (2014b). Meditation Awareness Training (MAT) for improved psychological wellbeing: A qualitative examination of participant experiences. Journal of Religion and Health, 53, 849–863. doi:10.1007/s10943-013-9679-0 Shonin, E., Van Gordon, W., & Griffiths, M. D. (2015). Does mindfulness work? British Medical Journal, 351, h6919. doi:10.1136/bmj.h6919 Sicras-Mainar, A., Rejas, J., Navarro, R., Blanca, M., Morcillo, A., Larios, R., . . . Villarroya, C. (2009). Treating patients with fibromyalgia in primary care settings under routine medical practice: A claim database cost and burden of illness study. Arthritis Research & Therapy, 11, R54. doi:10.1186/ar2673 Snijders, T. A. B.,&Bosker, R. J. (1999).Multilevel analysis: An introduction to basic andadvanced multilevel Modelling. London, UK: Sage. Van Gordon, W., Shonin, E., & Griffiths, M. D. (2015). Towards a second-generation of mindfulnessbased interventions. The Australian and New Zealand Journal of Psychiatry, 49, 591–592. doi:10.1177/0004867415577437 Van Gordon, W., Shonin, E., & Griffiths, M. D. (2016a). Meditation Awareness Training for individuals with fibromyalgia syndrome: An interpretative phenomenological analysis of participant's experiences. Mindfulness, 7, 409–419. doi:10.1007/s11469-016-9653-7 Van Gordon, W., Shonin, E., & Griffiths, M. D. (2016b). Meditation Awareness Training for the treatment of sex addiction: A case study. Journal of Behavioral Addiction, 5, 363–372. doi:10.1556/2006.5.2016.034 Van Gordon, W., Shonin, E., & Griffiths, M. D. (2016c). Ontological addiction: Classification, etiology, and treatment. Mindfulness, 7, 660–671. doi:10.1007/s11469-016-9653-7 Van Gordon, W., Shonin, E., Lomas, T., & Griffiths, M. D. (2016). Corporate use of mindfulness and authentic spiritual transmission: Competing or compatible ideals? Mindfulness and Compassion. doi:10.1016/j.mincom.2016.10.005 Meditation awareness training for treating FMS 205 Van Gordon, W., Shonin, E., Sumich, A., Sundin, E., & Griffiths, M. D. (2014). Meditation Awareness Training (MAT) for psychological wellbeing in a sub-clinical sample of university students: A controlled pilot study. Mindfulness, 5, 381–391. doi:10.1007/s12671-012-0191-5 Weissbecker, I., Salmon, P., Studts, J. L., Floyd, A. R., Dedert, E. A., & Sephton, A. E. (2004). Mindfulness-based stress reduction and sense of coherence among women with fibromyalgia. Journal of Clinical Psychology in Medical Settings, 9, 297–308. doi:10.1037/10725245.12.2.164 Wolfe, F. (2009). Fibromyalgia wars. Journal of Rheumatology, 36, 671–678. doi:10.3899/ jrheum.081180 Wolfe, F., Anderson, J., Harkness, D., Bennett, R. M., Caro, X. J., Goldenberg, D. L., . . . Yunus, M. B. (1997). Work and disability status of persons with fibromyalgia. Journal of Rheumatology, 24, 1171–1178. doi:10.1186/2046-4053-2-18 Wolfe, F., Br€ahler, E., Hinz, A., & H€auser, W. (2013). Fibromyalgia prevalence, somatic symptom reporting, and the dimensionality of polysymptomatic distress: Results from a survey of the general population. Arthritis Care and Research, 65, 777–785. doi:10.1002/acr.21931 Received 16 June 2016; revised version received 3 November 2016 Supporting Information The following supporting informationmay be found in the online edition of the article: Figure S1. Mixed effect model for DASS. Figure S2. Outcome means (intervention and control) across measurement intervals with two-tier 95% CIs. Figure S3. Example of mediation model paths. 206 William Van Gordon et al.