Mindfulness-based stress reduction (MBSR) is an 8-week well-defined and systematic patient-centered educational approach which uses relatively intensive training in mindfulness meditation as the core of a program to teach people how to take better care of themselves and live healthier and more adaptive lives (Kabat-Zinn
1996). The program consists of 8 weekly 2.5-h classes of 15–40 participants, one full-day retreat, and approximately 45 min per day of formal and informal practice (Santorelli
2014). MBSR is different from conventional meditation training and/or medical therapy in that it has (1) an educational rather than a therapeutic orientation, which makes use of relatively large “classes” of participants in a time-limited course structure to provide a community of learning and practice, and a “critical mass” to help in cultivating ongoing motivation, support, and feelings of acceptance and belonging; and (2) a medically heterogeneous environment, in which people with a broad range of health status and medical conditions participate in classes together without segregation by diagnosis or conditions and specializations of intervention (Griffith et al.
2019; Kabat-Zinn
1996). Numerous studies have shown benefits of the program in clinical and non-clinical populations on a variety of self-reported measures, including those of mindfulness, self-compassion, mood states, and perceived stress (Janssen et al.
2018; Khoury et al.
2015). In a review of the literature on impacts of MBSR, de Vibe et al. (
2017) reported mental health, somatic health, and health-related quality of life as among the key outcomes improved by MBSR, with effect sizes ranging from Hedges
g = 0.39–0.54. MBSR also has been shown to potentially affect brain function and anatomy (Tang et al.
2015; Young et al.
2018), as well as multiple biological processes from immunity (e.g., Davidson et al.
2003) to aging (e.g., Conklin et al.
2019).
With expanding applications of mindfulness to such fields as education, workplace, and justice (e.g., “Mindfulness All-Party Parliamentary Group”
2015), the general population is increasingly practicing mindfulness; in one study, 13% of US workers reported engaging in mindfulness-enhancing practices (Olano et al.
2015). Thus, a substantial proportion of participants in mindfulness-based interventions (MBI) such as MBSR may have practiced a variety of forms of meditation prior to participation. It is not known whether those regular meditators benefit from MBSR, since their baseline well-being, self-compassion, and other outcomes may have reached a ceiling level. On the other hand, unique features of MBSR, including systematic informal mindfulness practice, class dialogue/inquiry, didactic teaching, and emphasis on attitudinal qualities (Kabat-Zinn
1996; Santorelli
2014), which are missing or more implicit in most meditation practices in non-secular settings, may confer benefits to regular meditators beyond the level they have reached with regular meditation practice.
The literature is scant on the impacts of MBSR on regular meditators. A meta-analysis of 29 MBSR studies on healthy individuals (Khoury et al.
2015) reported on twelve studies using a standard MBSR protocol; of these, two studies (Cordon et al.
2009; Greeson et al.
2011) had a sample size of > 100, the minimum sample size that the authors considered to be sufficient to compare sub-groups of participants. Neither study described the participants’ prior meditation experience. In a more recent meta-analysis of 101 randomized controlled studies of MBSR (de Vibe et al.
2017), 39 studies used a standard MBSR protocol, and of these, only one study (de Vibe and Moum
2006) had > 100 MBSR participants. We also identified two other university/community-based MBSR studies using a standard MBSR protocol with the number of participants exceeding 100 (Carmody and Baer
2008; Carmody et al.
2009). None of these studies considered participants’ prior meditation experience.
The primary aim of this study was to assess the impacts of a mindfulness-based stress reduction (MBSR) program on a variety of self-report measures for novice meditators (NM) and regular meditators (RM). It was hypothesized that (1) RM would show higher baseline levels than NM on outcome measures; (2) both RM and NM would show improvements on outcome measures from baseline to post-program; and (3) there would be a significant interaction between Time and Group, with NM showing greater improvements than RM from baseline to post-program.
Discussion
The primary aim of this study was to compare the impacts of MBSR on mindfulness and various measures of well-being for novice meditators and regular meditators. The results showed that at baseline, RM scored higher on mindfulness and self-compassion scales than NM and had lower mood disturbance, lower perceived stress levels, and higher mental quality of life. After the program, both NM and RM showed significant improvements in these scales from baseline to post-program. NM’s post-MBSR scores were in fact comparable to RM’s baseline scores. The lack of a significant interaction between time (pre- to post-program) and group (NM vs. RM) on most of the outcome measures suggests that the improvements were generally comparable for the two groups.
The fact that a substantial proportion (38%) of the participants of the current MBSR program had already experienced meditation practice prior to joining MBSR may not be surprising, as secular meditation—particularly mindfulness—is increasingly practiced by the general population worldwide, and its application to a variety of areas in society is growing (e.g., Olano et al.
2015). We did not collect information on the type of meditation practiced by RM, so inferences about this are necessarily speculative. Nevertheless, the higher baseline FFMQ score for RM compared to NM may suggest that their primary practice was mindfulness (or Vipassana) meditation, which is gaining popularity in Japan primarily from Western influence and places emphasis on mindfulness skills such as observing as well as describing and acting with awareness, facets captured in FFMQ. It seems less likely that participants had been practicing Traditional Zen meditation (either the Soto or Rinzai tradition) as it places less emphasis on these skills. Other types of meditation, including Transcendental Meditation, are rarely practiced in Japan.
The overall effect sizes for NM on the scales (e.g., for FFMQ,
d = 0.80; for PSS
d = − 0.74) were roughly within the range reported in previous MBSR studies. For example, for a large community program, effect sizes were
d = 0.67 (FFMQ) and
d = − 0.50 (PSS) (Juul et al.
2018); for university-based programs cited in a review, effect sizes were
d = 0.47–0.90 (FFMQ subscales) and
d = − 1.02 (PSS) (Carmody and Baer
2008). Previous meditation experience was not reported for these studies, so it is not known if any of the participants were already regular meditators. It is notable that even a relatively brief intervention period of 8 weeks in MBSR improved scores on these measures for NM to levels comparable to those at baseline for RM, who had practiced meditation on a regular basis presumably much longer than 8 weeks (as a small sub-group of RM in our sample had practiced for a median of 2 years).
RM also showed significant improvements in the outcome measures. Although the effect sizes were generally numerically smaller in RM than NM, a significant interaction between Group (NM vs. RM) × Time (pre vs. post) was observed only for the FFMQ score (partial
η2 = 0.0025), suggesting that scores on SCS, TMD, MCS, and PSS improved for the two groups to similar degrees (with partial
η2 values for these measures ranging from 0.002 to 0.013). This is notable, as previous research has suggested that the impacts of MBSR appear to be greater for individuals with higher levels of distress at baseline (de Vibe and Moum
2006; Juul et al.
2018). The only outcome measure for which there was not an effect of Time for either group was PCS (the physical component summary of the Health-related Quality of Life Scale) [
F(1, 156) = 0.3,
p = 0.577,
η2 = 0.002]. Previous research has similarly found no change in PCS from pre- to post-MBSR for populations whose baseline PCS score is at or above the national mean (e.g., Greeson et al.
2011).
The fact that RM significantly improved on these measures beyond the level achieved by their previous regular meditation practice is likely due to many factors. It is unlikely that these improvements can be attributed simply to an increase in meditation time, as amount of practice time during the program among RM did not correlate with degree of improvement in any of the variables. Two alternative possibilities are discussed here.
One factor that might contribute to RM’s improvement in well-being beyond their already relatively high baseline levels is that MBSR has unique features compared to meditation alone. These MBSR features include a variety of formal practices such as body scan, mindful yoga and walking meditation, systematic informal practices, didactic teaching (including the relationships among thoughts, emotions, and bodily sensations), and the use of “classes” of participants in a time-limited course structure (Kabat-Zinn
1996; Santorelli
2014).
Another unique feature of MBSR involves the “great deal of guidance” with which the formal practices in MBSR were introduced (Kabat-Zinn
2011), compared to meditation learned and practiced with less guidance. For example, a guiding instruction commonly used in MBSR, such as, “There is no need in this practice to judge yourself negatively because becoming distracted is just part of training your attention,” has been shown to decrease mind-wandering (Rahl et al.
2017), and also potentially could foster non-judging and non-reactive attitudes as well. Both are components of FFMQ and non-judging is a component of SCS. Reduced mind-wandering, along with non-judgment and non-reactiveness, in turn might contribute to improvements of TMD (Evans et al.
2018) and PSS (Bränström et al.
2010).
An additional unique aspect of MBSR is that participants are given out-of-class assignments including one that invites them to notice and document pleasant and unpleasant events during the week along with their reactions to the events. This assignment provides participants with opportunities to expose themselves to potential sources of stress reactions through the lens of observation, which may also contribute to nonreactivity as captured in the FFMQ (Holzel et al.
2011), and in turn, to improvements of TMD (Evans et al.
2018) and PSS (Bränström et al.
2010). Also, the class group activities were designed to help maintain participants’ motivation, provide support, and foster feelings of acceptance and belonging (Kabat-Zinn
1996). These factors could contribute to the observed improvements in components of self-compassion (SCS), such as common humanity/isolation.
Dismantling studies (i.e., comparing a standard MBSR program with a program consisting solely of formal meditation practices) would help elucidate differential contributions of different program components on specific outcomes, providing further insights on the mechanisms of MBSR. In addition to such an approach, future studies could include gathering qualitative data pre- and post-MBSR by asking questions about which features were more or less valuable at the conclusion of the 8 weeks. This information may tease out what elements of the class are supportive to RM and NM, and also could be beneficial for teachers to understand what elements might be more or less important for both groups.
A second factor that might have contributed to RM’s improvement from baseline to post-MBSR involves this group’s motivations for signing up to take the course when they already had an independent meditation practice. Future research could examine participants’ motivations and how they might be associated with impacts from MBSR.
A body of evidence amassed in the past decade or so shows that MBSR can be beneficial for those with compromised well-being in clinical populations, such as those with chronic insomnia (Gross et al.
2011), with chronic pain (la Cour and Petersen
2015), and with chronic back pain (Morone et al.
2008), and in chronic caregivers (Whitebird et al.
2013), as well as those in non-clinical populations, such as academic healthcare employees (Geary and Rosenthal
2011) and healthcare providers (Goodman & Schorling,
2012). The current study provides evidence that people with higher-than-average well-being—even those with previous meditation practice—can benefit from MBSR as well. Thus, MBSR might be beneficial for individuals along the entire spectrum of well-being. This is consistent with a claim that mindfulness interventions may be beneficial not only for those with compromised well-being but for those who are already “resilient or flourishing” (Kuyken et al.
2017).
The finding that NM reached well-being levels post-MBSR comparable to those of RM at baseline does not necessarily mean that this 8-week program has the same impact as does longer-term meditation practice. Research comparing short-term with long-term meditators on a neuronal level using fMRI has shown that some changes in brain activity can occur in a relatively short period of time, while other changes require much more practice. For example, Kral et al. (
2018) showed emotionally positive and negative pictures to long-term meditators, short-term meditators (i.e., individuals who had undergone MBSR), and a control group of non-meditators. The authors measured reactivity in the amygdala, which is related to emotion regulation. Compared to non-meditators, both long-term and short-term meditators showed significantly less amygdala reactivity to emotionally positive pictures. It is notable that the short-term meditators’ amygdala reactivity in response to emotionally positive pictures post-MBSR decreased to levels comparable to those observed at baseline in the long-term meditators. In response to emotionally negative pictures, there were no group differences in amygdala reactivity between the non-meditators and either the short-term or the long-term meditators. However, among the long-term meditators, more retreat experience was related to reduced activation to negative pictures. In a similar study, Desbordes et al. (
2012) measured right amygdala activation in response to positive and negative pictures both before and after an 8-week mindful attention training intervention. Post-intervention, participants showed decreased right amygdala activation in response to positive pictures as well as to the pictures overall (i.e., positive and negative combined), but there was no significant decrease in reactivity to the negative pictures. Reduced emotional reactivity to both positive and negative stimuli is understood to be associated with well-being, as the brain does not become “hijacked” by wanting/grasping and aversion. Thus, de-activation to positive stimuli appears to happen relatively quickly, and only after more time practicing does the reactivity to negative stimuli decrease. This points to a complex process of change occurring as a result of meditation that continues over months and years.
A study by Brand et al. (
2012) also provides evidence that some benefits of meditation can begin to occur quickly (i.e., over an 8-week MBSR program), and then continue to improve if meditation is continued long-term. The authors measured cortisol levels (as well as self-report measures) in a small group of long-term meditators (LTM;
n = 9) and novice meditators (NM) who completed MBSR (
n = 11). Cortisol awakening response (CAR) was reduced from pre- to post-MBSR for NM to levels comparable to those observed in LTM, and for LTM, duration of meditation experience was negatively associated with CAR.
It is not known how long well-being related to decreased emotional reactivity and other underlying neurological and biochemical changes induced by MBSR remains if participants do not continue practicing after the program; it is possible that these later-occurring changes are necessary for more consistent, longer-term well-being. Addressing this important question will require longitudinal studies looking at post-MBSR changes over time in participants who do, versus do not, maintain meditation practice.
Limitations and Future Research
This study has both strengths and limitations. One source of strength was the use of instruments whose national normative data are established, which allowed us to compare NM and RM with the Japanese norm, with NM showing similar mood states and mental QOL, and RM showing lower mood disturbance and higher mental QOL compared to the Japanese norm. This comparison point enabled us to postulate potential implications of MBSR to a larger general population. An additional strength is the high response rate, ensuring minimal attrition bias; 87.5% of participants provided consent and pre- and post-assessment data. Similar studies typically have response rates between 50 and 75% (e.g., Carmody et al.
2009; Greeson et al.
2011; Juul et al.
2018). It is not entirely clear why our response rate was so much higher than that of similar studies, but contributing factors could include (1) differing norms and expectations within Japanese culture versus other cultures, (2) our efforts to stress to participants the importance of data collection at the orientation, (3) the high program completion rate among our initial participants who had provided consent (164 of 169, or 97.0%) as defined by attending 6 or more of the 8 weekly classes, and (4) our setting up time during the last session of the program to fill out the questionnaire.
One potential limitation of this study is the pre-post analysis design lacking a control group, which always raises the possibility that the observed improvements may have been temporary changes over time unrelated to the intervention. This seems unlikely, however, since the effects of MBSR observed in this study are in line with those reported in a systematic review and meta-analysis of randomized controlled studies (de Vibe et al.
2017) as well as a meta-analysis of studies for healthy individuals (Khoury et al.
2015). Furthermore, one could argue that observed improvements could be attributed to non-specific effects of treatment, such as attention or treatment contact, human interaction variables, and/or outcome expectations (Mohr et al.
2009). This is also unlikely, as many studies have shown that MBSR induces specific brain changes compared to active control conditions that included these non-specific effects of treatment (Gotink et al.
2016). Also, we did not collect detailed information on participants’ meditation practice prior to MBSR. In particular, we collected data on how long RM have been practicing meditation for only a small subset of participants. Furthermore, as there are variety of meditative practices and we did not collect data on the types of meditation practiced by participants, the conclusions of this study may not be generalizable to regular practitioners of all types of meditation. Future studies on the impacts of MBSR on participants with previous meditation experience should collect more detailed data, including type and duration of meditation practiced, retreat experience, etc.
Another potential limitation is the possibility of a common method bias (Podsakoff et al.
2012), as all of the outcome measures in this study consist of self-report Likert-type scales. Although procedural strategies to minimize the common method bias were used, such as explaining the purpose of the research to participants at the orientation to increase response accuracy and using scales containing both positive and negative (i.e., reverse coded) items (Jordan and Troth
2020), the potential impact of common method bias on the conclusion cannot be excluded.
A further limitation of this study, which is inherent in research comparing novices with non-novices, experts, or regular practitioners of any activity, is that the threshold we used to distinguish novices from regular meditators was somewhat arbitrary, at 45 min per week. While this threshold was chosen because of previous research showing that approximately this amount of time appeared to be required to benefit from MBSR (Davidson, et al.
2003), there is little research on the amount of regular meditation per week time required to derive benefits in the absence of formal programs that include weekly sessions with additional features beyond meditation alone. It is also likely that the amount of practice time per week is only one of many factors that contribute to the extent to which self-reported meditation is beneficial, including frequency and lifetime spent on practice (Soler et al.
2014), self-report accuracy, aspects of the particular meditation practiced, having the correct “attitude” while meditating (non-judgmental awareness, curiosity, gently bringing attention back when one becomes aware of being lost in thought, etc.), and interactions with person-level factors. Future research on the factors that contribute to beneficial impacts of meditation, including amount of time practiced, would help inform how studies should distinguish between different levels of meditation expertise. Future research should also address how long improvements from MBSR persist. Information from such research can inform potential changes to MBIs, such as encouraging ongoing practice after the program and developing “booster” MBIs for people who have previously participated in MBSR.
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