Nurturing compassion in schools: A randomized controlled trial of the effectiveness of a Compassionate Mind Training program for teachers

RESEARCH ARTICLE Nurturing compassion in schools: A randomized controlled trial of the effectiveness of a Compassionate Mind Training program for teachers Marcela MatosID 1 *, Isabel Albuquerque 1 , Ana Galhardo 1,2 , Marina Cunha 1,2 , Margarida Pedroso LimaID 1 , Lara Palmeira 1,3 , Nicola Petrocchi 4 , Kirsten McEwan 5 , Frances A. Maratos 5 , Paul Gilbert 5 1University of Coimbra, Faculty of Psychology and Educational Sciences, Center for Research in Neuropsychology and Cognitive and Behavioural Intervention (CINEICC), Coimbra, Portugal, 2Instituto Superior Miguel Torga, Coimbra, Portugal, 3Universidade Portucalense, Infante D. Henrique, Porto, Portugal, 4John Cabot University, Rome, Italy, 5University of Derby, College of Health, Psychology & Social Care, Derby, United Kingdom *[email protected] Abstract Objectives Schools are experiencing an unprecedented mental health crisis, with teachers reporting high levels of stress and burnout, which has adverse consequences to their mental and physical health. Addressing mental and physical health problems and promoting wellbeing in educational settings is thus a global priority. This study investigated the feasibility and effectiveness of an 8-week Compassionate Mind Training program for Teachers (CMT-T) on indicators of psychological and physiological wellbeing. Methods A pragmatic randomized controlled study with a stepped-wedge design was conducted in a sample of 155 public school teachers, who were randomized to CMT-T (n= 80) or a waitlist control group (WLC; n= 75). Participants completed self-report measures of psychological distress, burnout, overall and professional wellbeing, compassion and self-criticism at baseline, post-intervention, and 3-months follow-up. In a sub-sample (CMT-T, n= 51; WLC n= 36) resting heart-rate variability (HRV) was measured at baseline and post-intervention. Results CMT-T was feasible and effective. Compared to the WLC, the CMT-T group showed improvements in self-compassion, compassion to others, positive affect, and HRV as well as reductions in fears of compassion, anxiety and depression. WLC participants who received CMT-T revealed additional improvements in compassion for others and from others, and satisfaction with professional life, along with decreases in burnout and stress. Teachers scoring higher in self-criticism at baseline revealed greater improvements post CMT-T. At 3-month follow-up improvements were retained. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 1 / 36 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Matos M, Albuquerque I, Galhardo A, Cunha M, Pedroso Lima M, Palmeira L, et al. (2022) Nurturing compassion in schools: A randomized controlled trial of the effectiveness of a Compassionate Mind Training program for teachers. PLoS ONE 17(3): e0263480. https://doi. org/10.1371/journal.pone.0263480 Editor: Walid Kamal Abdelbasset, Prince Sattam Bin Abdulaziz University, College of Applied Medical Sciences, SAUDI ARABIA Received: November 3, 2021 Accepted: December 30, 2021 Published: March 1, 2022 Copyright: ©2022 Matos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data cannot be shared publicly because of the sensitive nature of some of the data collected. The data that support the findings of this study will be made available upon reasonable request from the University of Coimbra Institutional Data Access (contact via [email protected]) for researchers who meet the criteria for access to confidential data. Conclusions CMT-T shows promise as a compassion-focused intervention for enhancing compassion, wellbeing and reducing psychophysiological distress in teachers, contributing to nurturing compassionate, prosocial and resilient educational environments. Given its favourable and sustainable effects on wellbeing and psychophysiological distress, and low cost to deliver, broader implementation and dissemination of CMT-T is encouraged. Introduction The promotion of mental wellbeing constitutes a public health priority, with mental health difficulties being leading causes of disability and representing a long-lasting and major economic, social and health burden [1]. The United Nations 2030 Agenda for Sustainable Development [2] highlights the importance of promoting health and wellbeing for all ages and accentuates the need to foster compassion and empathy to tackle global inequality and cultivate peaceful and resilient societies. Schools are withstanding an unprecedented mental health crisis and have become increasingly stressful environments for the whole educational community [3]. Facing the multiple challenges of working in schools (e.g., excessive workload, time pressures, bureaucracy, pupil disruptive behaviours), teachers report high levels of stress and burnout within all education sectors and across countries [4]. In Portugal, the latest education sector research revealed that 75% of teachers present high levels of burnout, with 25% reporting extreme burnout and 84% intending to leave the profession due to stress and competitive pressures [5]. Along with this retention crisis in the teaching profession, long-term teacher stress is associated with a range of poor wellbeing and professional outcomes, which carry significant socioeconomic costs. For example, absenteeism and staff turnover, reduced self-efficacy [6,7], poor wellbeing and burnout [8–10], with adverse consequences to mental [6,11] and physical health [5,12,13]. The prolonged activation of stress-responsive physiological systems (e.g., hypothalamic-pituitaryadrenal axis; sympathetic nervous system) not only impairs psychological wellbeing [14] but also negatively affects neuroendocrine (e.g., cortisol), autonomic (e.g., heart rate variability, HRV) and immune-inflammatory responses [14,15], with long-lasting changes in stressrelated gene expression [16,17], which have a detrimental impact on mental and physical health. In addition, teacher’s stress negatively impacts pupils’ social adjustment, academic performance [18] and mental wellbeing [19–21]. For example, Oberle and Schonert-Reichl [22] revealed that student’s cortisol levels were much higher in classrooms led by a teacher who reported feeling overwhelmed. Longitudinal studies have further revealed that teachers reporting higher burnout early in the year have classrooms presenting more behavioural problems across the year [23]. When teachers report lower levels of work-related stress, students find those teachers more interested and enthusiastic in teaching [24], which influences pupils’ motivation and affect [25,26]. In addition, teachers’ wellbeing is linked to an array of positive outcomes, such as positive classroom processes (e.g., teachers’ active support towards students, classroom social climate), as well as students’ self-efficacy, subjective wellbeing, achievement, and motivation and attitude towards learning [27,28]. One source of teacher stress is the competitive dynamic of modern neoliberal societies that have come to texture learning environment and schools [29,30]. This competitiveness is a major source of stress, which is particularly evident in schools. This competitiveness is a major PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 2 / 36 Funding: This work has been funded by the Reed Foundation (UK) and supported by the Compassionate Mind Foundation (UK). Competing interests: The authors have declared that no competing interests exist. source of stress, affecting both teachers (e.g., heavier workloads, achievement focus, performance evaluation) and pupils (e.g., focus on academic achievement, self-interest). In fact, selfand other-focused competitive pressures have been highlighted as a key source for teachers and pupil mental health problems [31–34], and underlie fears of failure, feelings of shame and negative social comparisons, self-criticism and resistances to compassion [35–37]. Schools are crucial social arenas that can promote competitiveness and self-interest or cultivate prosociality and compassion, and where these two distinct motivational systems: competitiveness vs compassion, with their social information flows and biological patterns, become choreographed and played out [36,38]. Contrary to competitive motives, when individuals are caring and sharing, particular physiological systems linked to affiliation and social connectedness are stimulated [e.g., parasympathetic nervous system, oxytocinergic system), which contribute to wellbeing, stress management and emotion regulation, 39,40]. In fact, studies show that social relationships and adversity impact one’s physiology even at the epigenetic level [e.g., differential methylation in oxytocin receptor gene_OXTR, 17]. Compassion, commonly defined as a sensitivity to suffering in self and others with a commitment to try to alleviate and prevent it [41,42], is an innate prosocial motivation that evolved with the mammalian caring system. Compassion has benefits for mental health, emotion regulation and social relationships [e.g., 43–47]. Furthermore, compassion positively impacts physiological health, including influences in genetic expression [e.g., lower levels of CTRA-related gene expression, 48; epigenetic profiles of the OXTR, 49]. Experimental studies have also documented that cultivating compassion impacts physiological systems, reducing arousal and increasing parasympathetic activation [e.g., heart-rate variability, HRV, 50–53], decreasing sensitivity to threat [49], and activating specific neural circuits distinct from empathy and mindfulness training [54]. Given the burgeoning evidence of the numerous benefits of compassion over the past decade, several interventions have been developed that specifically aim to cultivate compassion [51]. A growing body of empirical evidence has testified their positive impact on mental and physical wellbeing and prosocial behaviour [55–57]. One of these approaches is an evolutionary and biopsychosocial evidence-based approach called Compassionate Mind Training [CMT; 42,58,59]. CMT was developed as an intervention for the general public and comprises psychoeducation and a set of core compassion and mindfulness practices taken from Compassion Focused Therapy [CFT; 58,60,61]. CFT, based upon evolutionary psychology, attachment theory, psychological science, and an understanding of motivational systems, is a transdiagnostic therapy for individuals dealing with shame and self-criticism, and currently delivered to patients with a wide range of mental and physical health difficulties. CFT has been shown to be an effective approach in a multitude of clinical conditions and symptoms [62,63]. CMT is designed to activate and develop evolved, affiliative care-focused motivational systems and emotions in order to down-regulate competitive and threat-focused systems and stimulate psychological and neurophysiological processes (primarily associated with the parasympathetic system) conductive to better emotion regulation, wellbeing, health and social relationships [58,60,61]. CMT uses a range of evidence-based practises such as breathing techniques, visualisations and behavioural practises to stimulate the vagus nerve, balance the autonomic nervous system [64] and recruit various neuro circuits associated with compassion [53,54]. CMT strives to cultivate a compassionate mind which includes the three interactive flows of compassion: the ability to be compassionate toward the self, and others, as well as to receive compassion from others. Each of these make a contribution to well-being and prosocial behaviour, but each can also have fears, blocks, and resistances that need to be tackled [58,61, 65]. CMT also addresses key issues linked to competitive threats such as self-criticism and fears of compassion [58,60,65]. PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 3 / 36 CMT seeks to develop mental competencies and physiological states that promote two fundamental interrelated processes of compassion. The first is the ability to be sensitive and turn towards suffering in self and others, to tolerate and engage with this suffering, rather than avoid it or dissociate, which is related to many attributes, such as the motivation to care and the capacity for feeling sympathy and empathy. The second is the commitment to alleviate and prevent suffering and requires a particular set of affiliative skills in the sphere of attention, emotion, cognition and behaviour conducive to the development of a compassionate mind [58,61]. Importantly, this means that individuals need to develop the courage to move towards suffering and potentially painful situations or mental states, but also the wisdom of knowing what to do. Hence CMT is centred around the development of competencies needed to courageously turn towards and engage with difficulties in self and others, and a variety of skills linked to reasoning, mentalizing and emotional regulation, which enable compassion motives to be translated into compassionate actions [42,61,65]. CMT has been tailored for use with different formats (e.g., length, practices) in nonclinical populations, namely the general public [66,67], health care educators and providers [68], mental health professionals [69], nurses [70,71], firefighters [72] and psychotherapy students [73]. There is a mounting evidence base for CMT effectiveness in improving mental and physiological health and prosocial behaviour [56,59,62,63]. A pilot randomised controlled study in a community sample [67,74] found that a brief CMT intervention promoted beneficial psychological changes associated with wellbeing and improvements in HRV. Higher HRV is indicative of higher parasympathetic nervous system outflow via the vagus nerve activity and is associated with self-compassion, feelings of perceived safeness and warmth and greater ability to self-soothe when stressed [e.g., 64,75–78]. A recent uncontrolled study demonstrated the promising effects of an 8-week CMT group intervention for the general public, in increasing levels of compassion, positive emotions and wellbeing, and reducing self-criticism and psychological distress, and validated the maintenance of these changes at 3-month follow-up [66]. In addition, a randomised controlled trial of CFT intervention as guided self-help in an adult community sample reported positive effects on wellbeing and psychopathological indicators up to 12 months after baseline [79]. This knowledge that promoting compassion (for self and others) has a range of psychological and physiological benefits for mental and physical wellbeing and prosocial behaviour [55] needs to be prioritised and incorporated into teacher education and into schools [36,80] and is aligned with international guidelines for the promotion of health and wellbeing [2,27]. Likewise, in Portugal, government recommendations for Education emphasise the importance of advancing health literacy and social-emotional competencies in educational settings to promote health and psychological wellbeing [81,82]. Recognising the growing problems of stress in schools and the crisis within the teaching profession, there are now a number of projects to improve wellbeing and resilience in teachers, with those stemming from compassion and mindfulness-based interventions demonstrating to be particularly effective [83–86]. One of these is the Compassionate Schools Research Initiative, which implemented and evaluated a 6-module Compassion Mind Training for Teachers (CMT-T), building upon previous CFT and CMT programs [67], in schools in Portugal and the UK. In the UK, an earlier version of the CMT-T, applied in 70 teachers and support staff, was feasible and well-received, with participants (N= 34) positively evaluating the curriculum and the practices and its helpfulness for dealing with emotional difficulties [32]. A subsample of 20 teachers completed preand post-self-report assessments and showed significant decreases in self-criticism and increases in self-compassion at post-intervention; however, burnout and psychopathology did not significantly change [32]. PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 4 / 36 In Portugal, an uncontrolled pilot study with 31 teachers showed that CMT-T was feasible and well-received, increased teachers’ compassion for others, self-compassion and compassion to others motivations and actions, and reduced depression, stress and fears of compassion to others [87]. Importantly, when self-criticism was controlled for, a decrease in burnout and an increase in self-compassion and in satisfaction with professional life were additionally found. In line with previous studies [88–90], this finding emphasises the importance of targeting selfcriticism across the intervention, given its key role in how CMT-T operates in promoting teachers’ abilities to be compassionate towards themselves and thus fostering their wellbeing and diminishing psychological distress. Furthermore, this study found that fears of compassion for others mediated the impact of CMT-T on teachers’ burnout and that self-compassion mediated the intervention effect on psychological wellbeing. Thus, these findings emphasise the importance of targeting both the fears, blocks and resistances to compassion alongside cultivating self-compassion abilities in teachers to decrease distress and promote psychological wellbeing. Finally, the qualitative experience of the CMT-T for both participants and facilitators suggested that future iterations of the program might benefit from extending the duration of sessions and length of the program [87]. Another study explored the international utility of the CMT-T and concluded this is a feasible, useful and effective intervention in cross-cultural educational settings, not only in terms of introducing and promoting a compassion-based school ethos but also on cultivating the psychological wellbeing of those working in education [91]. Therefore, CMT-T may provide a suitable approach to counteract the current challenges in educational settings and inspire a shift from competitiveness/threat-based to compassionate/ affiliative motivational systems, to improve educators’ stress regulation, prosocial qualities, behaviour and wellbeing. Still, a further evaluation of the pragmatic effectiveness of a refined version of CMT-T on teachers’ wellbeing and mental health, using a larger sample size and a randomized controlled design, is needed. Moreover, the impact of the CMT-T on affiliativeand stress-related biophysiological markers, particularly on the parasympathetic activity as measured through HRV [40,56], warrants empirical support. Additionally, as an alternative to traditional parallel designs, the use of a stepped wedge design would allow exposing both the intervention and control groups to the CMT-T, while also establishing a within-subjects psychological and physiological baseline in the control group and controlling for the confounding effect of time [92]. Given the growing research on the multidimensional benefits of compassion cultivation, and pilot studies on CMT-T, the current study sought to further explore the feasibility and effectiveness of the CMT-T on teachers’ psychological distress, wellbeing and compassion to self and others, by evaluating a refined 8-week version of the CMT-T and using a randomised controlled and stepped wedge design. CMT-T specifically aimed at promoting positive affect and satisfaction with professional life and reducing symptoms of depression, anxiety, stress, and burnout (primary outcome variables), by increasing the flows of compassion (for self, for others and from others), self-compassion and compassion to others motivations and actions, and by diminishing fears of compassion (for self, for others and from others) and self-criticism (secondary/process outcome variables). Furthermore, the present study aimed to explore the impact of the CMT-T on heart rate variability (HRV), an indicator of vagal regulatory activity and a physiological marker of a person’s ability to flexibly respond to environmental challenges and regulate emotional responses [56,75], which has been proposed as a primary measure to assess and train compassion [56]. It was hypothesised that CMT-T produces significant increases in HRV. In addition, the present study aimed at examining the impact of the CMT-T on teachers who received the intervention after a period of baseline observations where they acted as controls. It was hypothesised that these participants would reveal no significant PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 5 / 36 changes from baseline to pre-intervention but would reveal significant changes in both outcome and process variables after receiving the CMT-T intervention. In light of previous research pointing to the role of individual differences in self-criticism on how individuals respond to compassion-based interventions in general [88–90], and on the impact of CMT-T in particular [87], we also explored how self-criticism might influence the effects of the CMT-T intervention. Baseline self-criticism was hypothesized to impact the CMT-T effects on the process and outcome variables. Furthermore, we examined whether changes from pre-to-post CMT-T were different when comparing high and low self-critics, as well as whether there were differences between these two groups in the magnitude of change. In addition, the current study aimed to examine whether the effects of attending the CMT-T were sustained at 3-month post-intervention. Finally, given that the inter-relationship between the three flows of compassion (i.e., compassion for others, being open to compassion from others, and self-compassion) is a key aspect of the CFT/CMT approach [61,93], we explored whether the associations between the flows of compassion would change from before to after the CMT-T, particularly whether these were strengthened after training. Methods Study design The current study was a pragmatic two-arm randomized controlled trial (RCT), with one intervention group (CMT-T) and one waitlist control group (WLC), and a stepped-wedge design where all groups and participants in groups were offered the intervention. This study was approved by the Ethics Committee of the Faculty of Psychology and Educational Sciences of the University of Coimbra (CEDI22.03.2018), and registered at ClinicalTrials.gov (Identifier: NCT05107323; Compassionate Schools: Feasibility and Effectiveness Study of a Compassionate Mind Training Program to Promote Teachers Wellbeing). The findings of this RCT are reported conform the Consolidated Standards of Reporting Trials (CONSORT) guidelines [94; see S1 File] and the Journal Article Reporting Standards (JARS) for research in psychology [95]. Given the stepped wedge design, there were four assessment moments in the study: 1) Time 1 (T1)—baseline/pre-intervention assessment, was completed by the CMT-T group and the WLC group during the week previous to the start of the CMT-T intervention; 2) Time 2 (T2) —post-intervention assessment one was completed by CMT-T group and WLC group during the first-week post-intervention; 3) Time 3 (T3)—post-intervention assessment two, was completed by WLC group participants one week after they had also received the CMT-T intervention; 4) 3-months Follow-up assessment, this was conducted three months after the CMT-T conclusion (for all participants who completed the intervention). In T1, T2, and T3 all participants completed a set of self-report questionnaires assessing primary and secondary outcomes. A subsample of participants (n= 55 in the experimental group, and n= 40 in the WLC group) underwent the HRV measurement at T1, T2, and T3. In the 3-month follow-up assessment, only self-report data were collected. The study was implemented between October 2018 and August 2019, across the following phases: 1) October/November 2018 (T1 for CMT-T Groups 1&2 and for WLC Groups 1&2); 2) December 2018/January 2019 (T2 for CMT-T Groups 1&2 and for WLC Group 1&2; WLC Group 1&2 started the intervention; T1 for WLC Group 3); 3) March 2019 (T3 for WLC Group 1&2 after receiving the intervention; T2 for WLC Group 3, before starting the intervention; T1 for CMT-T Group 3); 4) May 2019 (T2 for CMT-T 3 Group; T3 for WLC Group 3, after receiving the intervention); 5) Follow-up assessment was conducted between MarchPLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 6 / 36 August 2019 by all participants who received the intervention 3-months after their respective group finished the CMT-T. Participants and recruitment In May/June 2018, participants were recruited amongst teaching staff in public schools (pre to high school grades) in the centre region of Portugal (Viseu and Coimbra districts). Schools’ boards were invited to participate in the study. Four schools enrolled in the project, provided further ethical approval and invited all teaching staff to attend an informative 2-h session about the study. This recruitment session was led by the research team in each school and included a brief description of the study aims, procedures, conditions for participation and ethical considerations. Additionally, a leaflet containing this information was distributed among staff by the schools’ Board. Teachers interested in participating in the study contacted the research team via email. They were then contacted via email and assessed for inclusion criteria and required to provide informed consent. Informed consent clarified the voluntary, confidential and anonymous nature of the study and data protection rights. Each participant created a unique and numerical code to guarantee confidentiality that was used in all assessment tasks. The assessment moments and intervention were conducted at the schools. Participants were eligible for participation if they: (a) were teachers in the enrolled schools; and (b) provided informed consent. Fig 1 displays the flow of participants. Overall, 164 teachers showed interest to take part in the study and met the eligibility criteria. Nine teachers failed to attend the baseline assessment. After baseline assessment, 155 participants were randomly assigned within each school to either the CMT-T intervention (CMT-T group) or the waitlist control (WLC) group. Each WLC group started the CMT-T after their parallel CMT-T group completed the intervention, i.e., after approximately two months. In total, six groups received the CMT-T (nper group M= 18), which was delivered in the school setting. From the initial 80 participants allocated to the CMT-T group, five failed to attend any session. Moreover, nine participants dropped-out (11.25%) because of work schedule incompatibility, and were excluded from further analysis. From the initial 75 participants allocated to the WLC group, 29 did not attend the second assessment and were also excluded from the analysis. The remaining 46 participants from the WLC group were allocated to the intervention at Time 2. From those, 37 received the intervention, and nine opted not to receive the intervention. There were no dropouts from the intervention at Time 2. Sociodemographic characteristics of participants are presented om Table 1. The study sample was composed of 155 teachers working in public schools from Portugal’s centre region. Participants’ age ranged from 25 to 63 years old, with a mean age of 51.35 (SD = 7.24). The majority of the participants was female (92.9) and held a graduate/honors degree (67.1%) or had completed a master’s degree (23.9%). Most participants were married (65.8%), 16.8% were divorced, and 13.5% were single. In terms of teaching-related characteristics, participants had been working as teachers for 10 months to 41 years (M= 27.01, SD = 8.29), and taught in several grade levels: 12.3% were preschool teachers, 16.1% taught in elementary school, 15.4% in middle school, 36.1% in high school, and 14.8% in special education. The participants qualified as middle or high school grade level teachers taught in the following content areas: 25.5% languages, 6.5% social and human sciences, 13.5% mathematics and experimental sciences, 2.6% artistic expression, 0.4% physical education, and 3.9% information technologies. Eight teachers did not provide information about these aspects. Regarding school setting, teachers were recruited in two large middle/high schools from an urban area, in one cluster of schools that included large schools from a semi-urban area and small schools from rural areas, and in one cluster of schools from an urban area including a large school and small schools from urban as well rural areas. PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 7 / 36 Independent samples ttests and chi-squared tests indicated that the intervention group and the waitlist control group were similar in age, sex, marital status, years of teaching and teaching subject areas, indicating a successful randomization. Significant differences were found between the two groups in education level and teaching grade level. Fig 1. Flowchart of study participants. https://doi.org/10.1371/journal.pone.0263480.g001 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 8 / 36 Intervention The Compassionate Mind Training Program for Teachers (CMT-T). The Compassionate Mind Training program for Teachers (CMT-T) is a compassion mind training intervention tailored for teaching staff and delivered in a group format across eight sessions of approximately 2.5 hours each. The 8-week CMT-T is a refined version of the 6-week CMT-T curriculum [87], which was developed based on an earlier version of the program for school staff designed and tested by Maratos et al. [32] and on a brief CMT program for the general public [67]. The feasibility and preliminary effectiveness of the pilot version of the CMT-T showed Table 1. Baseline characteristics of the participants (N= 155). Characteristic Total (N= 155) CMT-T (n= 80) WLC (n= 75) Test statistic (p-value) Age, years t (153) = .32 (p= .747) Mean (SD) 51.35 (7.24) 51.54 (8.21) 51.16 (6.09) Range 25–63 25–63 28–62 Sex n(%) χ 2 = .04 (p= .840) Male 11 (7.1) 6 (7.5) 5 (6.7) Female 144 (92.9) 74 (92.5) 70 (93.3) Marital status n(%) χ 2 = 2.28 (p= .684) Single 21 (13.5) 13 (16.3) 8 (10.7) Married/Registered partnership 102 (65.8) 52 (65) 50 (66.6) Divorced 26 (16.8) 12 (15) 14 (18.7) Widowed 6 (3.9) 3 (3.8) 3 (4) Education level n(%) χ 2 = 12.70 (p= .005) Bachelor 3 (1.9) - 3 (4) Graduate/Honors 104 (67.1) 60 (75) 44 (58.7) Postgraduate specialisation 11 (7.1) 1 (1.3) 10 (13.3) Masters 37 (23.9) 19 (23.8) 18 (24) Years of teaching experience, years t (153) = .07 (p= .946) Mean (SD) 27.01 (8.29) 27.05 (9.56) 26.96 (6.73) Range 0.83–41 0.83–41 2–38 Teaching grade level n(%) χ 2 = 18.54 (p= .001) Preschool 19 (12.3) 8 (10.0) 11 (14.7) Elementary school 25 (16.1) 18 (22.5) 7 (9.3) Middle school 24 (15.5) 4 (5.2) 20 (26.7) High school 56 (36.1) 34 (42.2) 22 (29.3) Special education (All levels) 23 (14.8) 11 (13.8) 12 (16.0) Missings 8 (5.2) 5 (6.3) 3 (4.0) Teaching subject areas n(%) χ 2 = 11.26 (p= .128) Several areas (Pre and Elementary School) 44 (28.4) 26 (32.5) 18 (24.0) Languages 38 (24.5) 13 (16.3) 25 (33.3) Social and human sciences 10 (6.5) 8 (10.0) 2 (2.7) Mathematics and experimental sciences 21 (13.5) 12 (15.0) 9 (12) Artistic expression 4 (2.6) 1 (1.2) 3 (4.0) Physical education 1(0.6) 1 (1.2) 0 (0.0) Information technologies 6 (3.9) 3 (3.7) 3 (4.0) Special Education (All areas) 23 (14.8) 11 (13.8) 12 (16.0) Missings 8 (5.2) 5 (6,3) 3 (4.0) Note. CMT-T = Compassionate Mind Training for Teachers; WLC = Waitlist control group. https://doi.org/10.1371/journal.pone.0263480.t001 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 9 / 36 burnout, depression, anxiety and stress, and safe, relaxed and activated positive affect. Medium-to-large effects sizes were found, except for burnout and stress, where effect sizes were small. A significant direct main effect of time for HRV (RMSSD) with a medium effect size was found. Significant direct group effects were found for compassion for self, compassion to others motivation and action, fears of compassion for self, self-criticism, intrapersonal mindfulness, safe and activated positive affect, depression and stress, with effect sizes ranging from small to medium. Table 3. Means, standard deviations before (T1) and after (T2) the CMT-T, time main effect, group main effect and time group interaction effect. CMT-T Group (N= 66) WLC Group (N= 46) Time Group Time X Group Measures Time M SD M SD F p η 2 pF p η 2 pF p η 2 p Compassion for Self (CEAS) T1 63.05 14.93 60.37 17.44 2.52 .115 .023 4.92 .029 .044 7.65 .007 .066 T2 68.52 14.99 58.89 16.12 Compassion for Others (CEAS) T1 76.63 13.04 75.72 13.08 0.208 .649 .002 2.59 .110 .023 5.47 .021 .048 T2 78.73 12.26 72.59 12.40 Compassion from Others (CEAS) T1 64.05 18.16 61.64 18.28 0.24 .625 .002 1.66 .201 .015 1.14 .287 .010 T2 64.83 16.32 59.53 14.36 Self-Compassion Motivation & Action (CMAS) T1 89.71 14.31 87.21 10.93 51.39 <.001 .318 26.40 .000 .194 40.06 <.001 .267 T2 107.18 12.57 88.30 12.31 Compassion to others Motivation & Action (CMAS) T1 58.42 10.41 56.63 9.08 47.28 <.001 .303 12.39 .001 .101 16.10 <.001 .128 T2 69.24 9.80 59.50 10.40 Fears of Compassion for Self T1 7.47 7.51 9.13 7.69 1.66 .201 .015 7.42 .008 .063 5.83 .017 .050 T2 4.76 7.11 9.96 8.22 Fears of Compassion for Others T1 13.89 7.04 12.35 6.52 18.86 <.001 .146 1.15 .287 .010 20.41 <.001 .157 T2 8.39 7.23 12.46 6.67 Fears of Compassion From Others T1 10.14 7.59 11.18 8.28 0.94 .334 .009 2.95 .089 .26 4.51 .036 .040 T2 8.28 7.88 11.93 8.84 Self-criticism T1 15.68 7.19 18.80 8.94 0.11 .743 .001 8.27 .005 .071 2.95 .089 .027 T2 14.40 7.34 19.67 9.77 Safe PA T1 2.38 .70 2.29 .66 13.61 <.001 .111 6.16 .015 .053 11.10 .001 .092 T2 2.81 .69 2.31 .71 Relaxed PA T1 2.18 .75 2.13 .83 12.80 .001 .105 3.17 .078 .028 9.17 .003 .078 T2 2.62 .80 2.17 .81 Activated PA T1 2.64 .69 2.50 .74 9.95 .002 .084 4.77 .031 .042 6.62 .011 .057 T2 2.94 .55 2.53 .75 Satisfaction with Professional Life T1 14.62 4.88 12.57 4.47 1.63 .205 .015 1.33 .251 .012 7.316 .008 .063 T2 14.06 5.23 14.11 5.02 Burnout T1 48.26 16.32 54.47 15.17 4.72 .032 .041 3.38 .069 .030 0.95 .333 .009 T2 46.89 14.11 50.89 16.56 Depression T1 2.94 3.13 4.72 4.49 13.44 <.001 .109 11.02 .001 .091 0.06 .803 .001 T2 1.82 1.68 3.74 3,83 Anxiety T1 2.97 3.54 4.24 3.65 10.78 .001 .089 3.99 .048 .035 0.22 .643 .002 T2 2.13 2.63 3.13 3.56 Stress T1 6.45 3.84 8.02 4.28 4.56 .035 .040 6.52 .012 .056 0.03 .867 .000 T2 5.71 2.97 7.15 3.53 HRV (RMSSD in ms 2 ) CMT-T (n= 51); WLC (n= 36) T1 31.48 21.94 32.49 18.98 5.29 .024 .059 0.18 .892 <.001 0.76 .386 .009 T2 37.62 31.85 35.26 20.08 Note: CMAS = Compassion Motivation and Action Scale; CEAS = Compassion Engagement and Action Scales; PA = Positive affect. https://doi.org/10.1371/journal.pone.0263480.t003 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 16 / 36 There was a significant medium-to-large effect of the intervention (i.e., time x group interaction effects) on compassion for self, self-compassion and compassion to others motivation and action, fears of compassion for others, safe, relaxed and activated positive affect, and satisfaction with professional life. Significant time x group interaction effects with small effect sizes were found for compassion for others and fears of compassion for self and from others. Differences within groups in changes from pre-intervention to postintervention Mean differences from preto post-intervention in the study variables were then examined within each group through repeated measured ANOVAs. According to Table 4, when comparing mean scores in the CMT-T group before (T1) and after the program completion (T2), regarding those variables with significant time x group effects, significant increases were found in compassion for self, self-compassion motivation and action, compassion to others motivation and action, and in safe, relaxed and activated positive affect. Furthermore, there were significant decreases in fears of compassion for self, for others and from others. Results regarding those variables where no significant time x group effects were found, revealed that in the CMT-T group, there was also a significant decrease in depression and anxiety symptoms. The same analysis was conducted in the WLC group, a significant decrease was found for compassion for others, along with an increase in satisfaction with professional life, from T1 to T2. Significant decreases were also found for burnout and anxiety symptoms. We did not find a significant time x group interaction effect on HRV. However, given the reduced number of participants undertaking HRV measurements which might have impacted Table 4. Mean comparisons at T1 and T2 in the CMT-T and the in WLC group. CMT-T Group _T1 (N= 66) CMT-T Group_T2 (N= 66) WLC Group_T1 (N= 46) WLC Group_T2 (N= 46) M SD M SD F (65) pη 2 pM SD M SD F (45) pη 2 p Compassion for Self (CEAS) 63.05 14.93 68.52 14.99 9.71 .003 .134 60.37 17.44 58.89 16.12 .78 .382 .017 Compassion for Others (CEAS) 76.63 13.04 78.73 12.26 1.80 .184 .028 75.72 13.08 72.59 12.40 4.46 .040 .090 Compassion from Others (CEAS) 64.05 18.16 64.83 16.32 0.20 .655 .003 61.64 18.28 59.53 14.36 1.06 .309 .024 Self-Compassion Motivation & Action (CMAS) 89.71 14.31 107.18 12.57 83.96 <.001 .564 87.21 10.93 88.30 12.31 0.56 .459 .012 Compassion to others Motivation & Action (CMAS) 58.42 10.41 69.24 9.80 74.47 <.001 .534 56.63 9.08 59.50 10.40 3.43 .070 .071 Fears of Compassion for Self 7.47 7.51 4.76 7.11 8.18 .006 .112 9.13 7.69 9.96 8.22 0.56 .460 .012 Fears of Compassion for Others 13.89 7.04 8.39 7.23 44.96 <.001 .409 12.35 6.52 12.46 6.67 0.01 .905 .000 Fears of Compassion From Others 10.14 7.59 8.28 7.88 5.51 .022 .078 11.18 8.28 11.93 8.84 0.62 .434 .014 Self-criticism 15.68 7.19 14.40 7.34 2.22 .141 .034 18.80 8.94 19.67 9.77 1.04 .313 .023 Safe PA 2.38 .70 2.81 .69 28.65 <.001 .309 2.29 .66 2.31 .71 0.06 .811 .001 Relaxed PA 2.18 .75 2.62 .80 25.47 <.001 .285 2.13 .83 2.17 .81 0.14 .715 .003 Activated PA 2.64 .69 2.94 .55 24.87 <.001 .280 2.50 .74 2.53 .75 0.11 .739 .002 Satisfaction with Professional Life 14.62 4.88 14.06 5.23 1.34 .252 .020 12.57 4.47 14.11 5.02 6.08 .018 .119 Burnout 48.26 16.32 46.89 14.11 0.83 .367 .013 54.47 15.17 50.89 16.56 4.66 .036 .096 Depression 2.94 3.13 1.82 1.68 11.21 .001 .147 4.72 4.49 3.74 3.83 3.99 .053 .081 Anxiety 2.97 3.54 2.13 2.63 4.99 .029 .071 4.24 3.65 3.13 3.56 5.70 .021 .112 Stress 6.45 3.84 5.71 2.97 2.19 .144 .033 8.02 4.28 7.15 3.53 2.53 .118 .053 HRV (RMSSD in ms 2 ) CMT-T (n= 51); WLC (n= 36) 31.48 21.94 37.62 31.85 5.96 .018 .107 32.49 18.98 35.26 20.08 .894 .351 .025 Note: CMAS = Compassion Motivation and Action Scale; CEAS = Compassion Engagement and Action Scales; PA = Positive affect. https://doi.org/10.1371/journal.pone.0263480.t004 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 17 / 36 on the significance of the time x group interaction, the medium effect size found for the direct main effects of time, and a clear trend emerging by the visual inspection of the plot (Fig 2), we exploratively inspected mean differences at HRV (RMSSD) before (T1) and after the CMT-T (T2) in the two groups, separately. Repeated measured ANOVA showed a significant increase in HRV from T1 to T2, with a large effect size, only in the experimental group. Interestingly, the WLC showed a non-significant increase in HRV from T1 to T2 (see Table 4). The role of self-criticism When controlling for baseline self-criticism, a significant time x self-criticism interaction effect was found (F= 1.90, p= .020, η 2 p = .368). In addition, significant effects of the intervention (i.e., time x group effects) were found for: compassion for self (F= 10.24, p= .002, η 2 p = .095), compassion for others (F= 4.33, p= .040, η 2 p = .043), self-compassion motivation and action (F= 47.22, p<.001, η 2 p = .327), compassion to others motivation and action (F= 14.37, p< .001, η 2 p = .129), fears of compassion for self (F= 5.41, p= .022, η 2 p = .053) and for others (F= 15.36, p<.001, η 2 p = .137), as well as safe (F= 9.23, p= .003, η 2 p = .087), relaxed (F= 8.48, p= .004, η 2 p = .080) and activated (F= 5.73, p= .019, η 2 p = .056) positive affect, and satisfaction with professional life (F= 5.35, p= .023, η 2 p = .052). Paired-samples T-tests comparing high and low self-critics in the CMT-T group between baseline (T1) and post-intervention (T2) were then performed (Table 5). The high self-critics showed a significant increase in compassion for self, self-compassion motivation and action, Fig 2. Time ×group interaction for HRV (RMSSD; ms2). https://doi.org/10.1371/journal.pone.0263480.g002 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 18 / 36 compassion to others motivation and action, and in safe, relaxed and activated positive affect. These participants also revealed a significant decrease in fears of compassion for self and for others, in self-criticism and in depression and anxiety symptoms. As for the low self-critics, they showed a significant increase in self-compassion and compassion to others motivations and actions, and in safe, relaxed and activated positive affect, as well as significant decreases in fears of compassion for others. All effect sizes ranged from medium to large. To examine potential differences in the magnitude of change from pre-to-post intervention between high and low self-critics, change scores (T2 –T1) were computed, and independent samples t-test’s calculated. Results revealed no significant differences between high and low self-critics in the magnitude of change in all study variables, with the exception of anxiety [t (47) = -2.10, p= .041] and self-criticism [t (46) = -3.57, p= .001], where the change was greater in the high self-criticism group. Stepped wedge analysis: Differences in changes from baseline, preintervention to post-intervention within the WLC group’ participants who completed the CMT-T Repeated Measures ANOVAs were performed to test differences in all study’s variables from baseline to pre-intervention and post-intervention (Table 6) in the WLC group participants who completed the CMT-T between T2 and T3. At post-intervention, participants presented increased levels of the three flows of compassion (for self, for others and from others), selfcompassion and compassion to others motivations and actions, positive affect (safe, relaxed, activated) and satisfaction with professional life, as well as decreased fears of compassion (for self, for others and from others), burnout, depression, anxiety and stress symptoms. All differences reflected large effect sizes. Table 5. Mean comparisons at T1 and T2 for the high self-criticism group (N= 31) and the low self-criticism group (N= 18) within the CMT-T group. High Selfcriticism _T1 High Selfcriticism _T2 Low Selfcriticism _T1 Low Selfcriticism _T2 M SD M SD t p d M SD M SD t p d Compassion for Self (CEAS) 60.80 16.75 67.27 14.80 -2.17 .038 .40 67.59 12.88 69.94 15.25 -0.70 .495 .17 Compassion for Others (CEAS) 76.24 14.24 79.04 13.54 -1.17 .253 .22 79.67 13.23 77.00 13.80 0.82 .426 .19 Compassion from Others (CEAS) 61.60 18.08 60.80 16.96 0.32 .750 .06 72.50 15.62 68.56 15.19 1.32 .204 .25 Self-Compassion Motivation & Action (CMAS) 87.32 15.43 108.58 12.03 -7.07 <.001 1.27 91.39 11.29 104.39 14.39 -3.52 .003 .83 Compassion to Others Motivation & Action (CMAS) 59.16 11.37 70.45 9.15 .6.11 <.001 1.10 55.72 9.70 66.22 11.99 -3.79 .001 .93 Fears of Compassion for Self 10.45 8.69 6.16 9.36 2.27 .031 .41 3.89 4.52 2.33 2.89 2.04 .058 .48 Fears of Compassion for Others 15.39 6.13 10.06 7.81 4.95 <.001 .89 11.28 7.78 7.50 6.37 2.92 .010 .69 Fears of Compassion from Others 12.90 8.22 10.29 9.72 1.66 .108 .30 6.17 5.93 5.22 4.67 0.91 .375 .22 Self-Criticism 21.83 4.80 17.80 6.89 3.17 .004 .58 7.28 2.52 9.89 5.95 -2.34 .032 .55 Safe PA 2.14 .68 2.63 .65 -3.90 .001 .72 2.72 .78 3.06 .70 -3.06 .007 .74 Relaxed PA 2.05 .91 2.66 .77 -4.86 <.001 .88 2.34 .62 2.68 .86 -2.39 .029 .56 Activated PA 2.45 .77 2.86 .56 -4.74 <.001 .86 2.82 .65 3.08 .55 -2.39 .029 .56 Satisfaction with Professional Life 13.77 5.12 13.77 5.59 0.00 1.00 .00 15.88 5.28 15.53 5.77 .536 .599 .13 Burnout 54.65 14.80 53.23 13.33 .631 .533 .11 43.67 17.43 40.78 13.99 0.97 .348 .23 Depression 4.03 3.54 2.23 1.54 3.15 .004 .56 2.00 2.77 1.17 1.29 1.59 .131 .39 Anxiety 4.35 4.23 2.74 3.31 2.62 .014 .47 1.50 1.69 1.78 1.73 -0.55 .593 .13 Stress 7.29 4.25 6.48 3.20 1.02 .320 .18 6.28 3.34 5.06 2.64 1.41 .178 .33 Note: CMAS = Compassion Motivation and Action Scale; CEAS = Compassion Engagement and Action Scales; PA = Positive affect. https://doi.org/10.1371/journal.pone.0263480.t005 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 19 / 36 Furthermore, post-hoc pairwise comparisons revealed no significant changes from baseline to pre-intervention in any of the study variables except for symptoms of depression and anxiety, which decreased between T1 and T2. Between baseline and post-intervention, participants showed significant improvements in self-compassion and compassion from others, self-compassion and compassion to others motivations and actions, positive affect (safe, relaxed, activated) and satisfaction with professional life, along with significant reductions in fears of compassion (for self, for others and from others), burnout, and depression, anxiety and stress symptoms. In addition, between pre-intervention and post-intervention, participants revealed significant increases in the three flows of compassion (for self, for others and from others), in self-compassion and compassion to others motivations and actions and in positive affect (safe, relaxed, activated). They also revealed significant decreases in fears of compassion (for self, for Table 6. Means and SDs of the outcome measures at baseline (T1), pre-intervention (T2) and post-intervention (T3) and repeated measures analysis of variance (N= 37) and pairwise comparisons, for the WLC group participants who completed the CMT-T intervention between T2 and T3. Baseline (T1) Pre-intervention (T2) Post-Intervention (T3) F p η 2 p Pairwise Comparisons Outcome measures M (SD) M (SD) M (SD) T1-T2 p T1-T3 p T2-T3 p Compassion for Self (CEAS) a 59.66 (16.51) 59.22 (15.79) 68.38 (16.12) 9.84 .001 .241 .438 (1.79) .809 -8.72 (2.83) .004 -9.16 (2.25) <.001 Compassion for Others (CEAS) 74.66 (14.52) 73.06 (13.19) 77.75 (12.66) 3.68 .031 .106 1.59 (1.76) .372 -3.09 (1.82) .100 -4.69 (1.69) .009 Compassion from Others (CEAS) a 60.06 (18.55) 58.63 (15.02) 68.50 (16.61) 7.10 .004 .186 1.44 (2.43) .559 -8.44 (3.46) .021 -9.88 (2.49) <.001 Fears of Compassion for Self 9.84 (8.72) 10.66 (8.48) 5.28 (6.99) 9.31 <.001 .231 -.813 (1.35) .551 4.56 (1.40) .003 5.38 (1.28) <.001 Fears of Compassion for Others 13.28 (6.91) 12.66 (7.20) 6.31 (5.41) 24.45 <.001 .441 .625 (.997) .527 6.97 (1.20) <.001 6.34 (1.12) <.001 Fears of Compassion From Others 12.66 (8.94) 12.47 (9.40) 8.50 (7.79) 6.84 .002 .181 .188 (1.19) .876 4.16 (1.31) .003 3.97 (1.30) .005 Self-Compassion Motivation & Action (CMAS) 87.13 (11.39) 88.25 (11.64) 108.06 (13.39) 70.09 <.001 .693 -1.13 (1.79) .535 -20.94 (2.01) <.001 -19.81 (2.15) <.001 Compassion to others Motivation & Action (CMAS) 55.84 (9.16) 59.25 (9.63) 71.16 (9.01) 46.02 <.001 .598 -3.31 (1.82) .071 -15.31 (1.61) <.001 -11.91 (1.58) <.001 Self-criticism a 17.75 (8.53) 18.72 (9.16) 18.08 (10.82) .310 .664 .010 -.97 (.94) .311 -.34 (1.58) .829 .63 (1.14) .587 Burnout a 53.75 (14.99) 50.28 (17.39) 43.22 (15.56) 9.53 .001 .235 3.47 (1.75) .056 10.53 (2.71) .001 7.06 (2.78) .016 Depression a 4.97 (4.76) 3.28 (3.43) 2.38 (2.59) 8.59 .001 .217 1.69 (.57) .006 2.59 (.78) .002 .91 (.52) .092 Anxiety 4.16 (3.73) 2.53 (3.03) 2.09 (2.25) 8.73 .001 .220 1.63 (.53) .004 2.06 (.55) .001 .44 (.48) .370 Stress 8.28 (4.22) 7.13 (3.77) 6.50 (2.65) 3.32 .043 .097 1.16 (.64) .081 1.78 (.79) .031 .63 (.66) .354 Safe PA 2.33 (.74) 2.40 (.71) 2.78 (.76) 9.55 <.001 .235 -.07 (.11) .517 -.45 (.12) .001 -.38 (.10) .001 Relaxed PA 2.10 (.76) 2.18 (.80) 2.70 (.83) 13.08 <.001 .297 -.08 (.11) .492 -.60 (.12) <.001 -.52 (.15) .002 Activated PA 2.53 (.84) 2.59 (.83) 2.79 (.79) 3.95 .024 .113 -.06 (.09) .531 -.26 (.10) .017 -.20 (.09) .045 Satisfaction with Professional Life 13.41 (4.43) 14.94 (5.04) 15.78 (4.50) 6.13 .004 .165 -1.53 (.79) .063 -2.36 (.60) <.001 -.84 (.65) .204 Threat Emotions - 6.25 (2.89) 5.72 (2.80) 3.61 .065 .094 - - - - .53 (.28) .065 Soothing Emotions - 13.31 (2.75) 14.06 (2.46) 3.97 .050 .102 - - - - -.75 (.38) .050 Drive Emotions - 11.92 (3.31) 13.33 (3.22) 13.69 .001 .281 - - - - -1.42 (.38) .001 HRV (RMSSD in ms 2 ; n = 36) 32.49 (18.98) 35.25 (20.08) 35.04 (17.85) .46 .631 .010 -2.76 (17.55) .351 .21 (21.07) .952 -2.55 (18.73) .419 Note: a = Greenhouse-Geisser correction; CMAS = Compassion Motivation and Action Scale; CEAS = Compassion Engagement and Action Scales; PA = Positive affect. https://doi.org/10.1371/journal.pone.0263480.t006 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 20 / 36 others and from others) and burnout. The emotional climate at work was also assessed in these participants at T2 and T3, and significant increases in soothing/safeness and drive/vitality emotions at work were found from pre-to-post-intervention. A decrease in threat emotions at work was also observed, but did not reach the significance threshold. Three-month follow-up comparison with post-intervention Repeated measures ANOVAs results considering post-CMT-T (T2) and the 3-months followup (T3) are presented in Table 7. No significant differences were found for all the considered variables pointing to the maintenance of the CMT-T therapeutic gains, except for self-compassion motivations and actions and compassion (to others) motivations and actions. Pairwise comparisons showed a significant decrease from T2 to T3 in the self-compassion motivations and actions (p<.001) and in the compassion to others motivations and actions (p= .020). How are the flows of compassion related preand post-intervention? We explored whether the association between the flows of compassion changed from pre-to-post intervention in all participants who completed the CMT-T. Prior to the CMT-T, correlations between the three flows were moderate: r Self-compassion—Compassion for Others = .54, p<.001; r Self-compassion—Compassion From Others = .40, p<.001; r Compassion for Others—Compassion From Others = .39, p<.001. After the intervention, correlations between the flows increased in magnitude across all the flows: r Self-compassion—Compassion for Others = .60, p<.001; r Self-compassion—Compassion From Others = .54, p<.001; r Compassion for Others—Compassion From Others = .52, p<.001. Table 7. Mean comparisons at post-CMT-T (T3) and 3-months follow-up (T4), effect size and observed power (N= 48). T3 T4 Outcome measures M SD M SD F (1, 46) pη 2 p Observ. power Compassion for Self (CEAS) 69.35 13.92 66.89 13.10 2.93 .094 .06 .389 Compassion for Others (CEAS) 78.33 12.26 77.16 12.51 0.84 .366 .02 .145 Compassion from Others (CEAS) 63.22 16.41 60.57 14.04 2.02 .162 .04 .285 Self-Compassion Motivation & Action (CMAS) 109.72 10.10 102.72 13.05 14.52 <.001 .24 .961 Compassion to others Motivation & Action (CMAS) 71.49 9.75 67.37 11.12 5.82 .020 .12 .654 Fears of Compassion for Self 6.28 8.70 8.19 12.28 2.03 .161 .04 .286 Fears of Compassion for Others 8.74 7.79 10.02 9.45 2.24 .141 .05 .311 Fears of Compassion From Others 9.32 8.73 10.11 10.98 0.40 .532 .01 .095 Self-criticism 16.88 9.50 15.84 9.90 0.64 .427 .02 .123 Safe PA 2.76 0.75 2.70 0.67 0.32 .572 .01 .086 Relaxed PA 2.78 0.63 2.76 0.69 0.02 .884 .00 .052 Activated PA 2.82 0.63 2.87 0.64 0.46 .499 .01 .102 Satisfaction with Professional Life 15.33 4.44 15.59 4.45 0.26 .614 .01 .079 Burnout 43.59 12.35 45.02 16.49 0.52 .476 .01 .108 Depression 2.30 2.26 2.93 3.83 1.33 .255 .03 .204 Anxiety 2.45 2.64 2.43 3.18 0.00 .957 .00 .050 Stress 6.29 2.69 5.47 3.63 3.18 .081 .07 .415 Threat Emotions 5.48 2.65 5.08 2.66 1.02 .322 .04 .163 Soothing Emotions 13.94 2.30 13.88 1.93 0.05 .835 .00 .055 Drive Emotions 13.25 2.69 13.21 2.32 0.01 .929 .00 .051 Note: CMAS = Compassion Motivation and Action Scale; CEAS = Compassion Engagement and Action Scales; PA = Positive affect. https://doi.org/10.1371/journal.pone.0263480.t007 PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 21 / 36 Discussion Schools are facing an unparalleled mental health crisis. Teachers within all education sectors and across countries increasingly reveal elevated stress and burnout and intend to leave the profession [3,4]. This scenario is particularly concerning in Portugal, where teachers’ stress and burnout are prevalent and associated with the competitive pressures and growing retention crisis in the teaching profession [5]. Importantly, teachers’ stress has adverse consequences to their mental and physical health and negatively influences pupils [e.g., 5,8]. Furthermore, this raises serious economic, healthcare and societal challenges. Therefore, it is crucial to promote adaptive cognitive and emotional regulation that supports teachers in coping with the challenges of the school context and promotes their mental wellbeing. Growing empirical support has highlighted the beneficial impact of compassionate-based interventions on improving emotional regulation skills central to stress regulation [63]. In educational settings, the Compassionate Schools Research Initiative developed and examined the impact of a Compassion Mind Training intervention for Teachers (CMT-T), in schools in Portugal and the UK, and found empirical support for its international utility, feasibility and preliminary effectiveness on a range of mental health indicators [32,87,91]. The current study intended to expand this preliminary evidence and test the feasibility and effectiveness of a refined version of the CMT-T on teachers’ psychological distress, wellbeing, compassion to self and others, and heart rate variability (HRV), using a randomised controlled and stepped wedge design in a larger sample. The CMT-T had a high attendance rate, and teachers considered the intervention very important and helpful. They were highly motivated to attend the sessions and would recommend it to colleagues. These findings suggest that the revised 8-week CMT-T was highly rated in terms of acceptability and revealed adequate practicality and adaptation, providing evidence that the CMT-T is a feasible intervention for teachers. These feasibility results are in support of previous pilot studies using an earlier version of the CMT-T in Portugal and the UK [32,87, 91], reinforcing the acceptability of CMT-T modules and practices. In particular, teachers found the modules’ Building a compassionate mind/self’, ’Understanding and working with self-criticism’, and ’Understanding the functions of our emotions’ to be the most helpful. In general, this is similar to the results reported in the Portuguese pilot study [87]. In both studies, the two modules addressing the soothing system’s cultivation and the development of the compassionate mind/self and, multiple selves, were chosen by teachers as the most useful. Interestingly in this refined CMT-T, where self-criticism was targeted throughout the intervention, the module focused on the functional analysis of self-criticism and using the compassionate self to deal with it was also identified as a very relevant one. In line with Matos et al. [87], the practices assessed as the most helpful by the teachers were the Soothing Rhythm Breathing, Compassion for the self, Building the compassionate self, followed by Mindfulness and Safe Place Imagery. These acceptability results extend current knowledge on the evaluation of CMT interventions with community samples [e.g., 66,67,74] and should inform the development, implementation and evaluation of CMT interventions in future research. The present randomised controlled study revealed significant time x group interaction effects of the CMT-T on compassion for self, self-compassion and compassion to others motivation and action, fears of compassion for others, safe, relaxed and activated positive affect, and satisfaction with professional life, with medium to large effect sizes. Moreover, significant time x group interaction effects with small effect sizes were also found for compassion for others and fears of compassion for self and from others. These findings partially support our hypotheses and are discussed in detail below concerning the process and outcome variables. PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 22 / 36 The results highlighted several differences between groups. Regarding the effects of the CMT-T on self-compassion, compared with the WLC group, teachers in the CMT-T group revealed a significant increase in compassion for self and self-compassion motivation and action and a significant reduction in fears of compassion for self. These changes represented medium to large effect sizes. Stepped wedge analyses further corroborated these findings revealing that teachers who received the intervention after acting as controls also showed significant improvements in compassion for self and self-compassion motivation and action, and significant decreases in fears of compassion for self after completing the CMT-T. These results corroborate our hypotheses, indicating that after the CMT-T, teachers improved their sensitivity and engagement with their own suffering, along with an enhanced motivation to engage with life’s difficulties and suffering with a caring and accepting attitude towards oneself, instead of withdrawing, avoiding or denying those difficulties. They also revealed an increased ability to tolerate distress concerning oneself, to be kind and supportive when facing hardships, and showed a greater capacity to act compassionately towards themselves. Simultaneously, the CMT-T produced a decline in fears, blocks and resistances to be self-compassionate. These results extend those reported by Matos et al. [87], documenting significant increases in teachers’ self-compassion motivation and action (as assessed by the CMAS) after the CMT-T, but where changes in self-compassion attributes and competencies (as measured by the CEAS), and fears of compassion for self, did not reach statistical significance. In the present study, significant improvements in compassion engagement and action towards oneself (as measured by the CEAS) were additionally found in teachers at post-intervention, which is in line with previous studies showing similar results using CMT in community samples [66,67]. This finding suggests that this refined longer version of CMT-T not only promotes an increase in one’s motivation to be accepting and caring, to tolerate distress, and to commit to behaving compassionately towards oneself (as assessed by the CMAS), but also diminishes the inhibitors to be self-compassionate, and fosters the sensitivity to and engagement with one’s suffering including competencies of sensitivity, sympathy, empathy, distress tolerance, non-judgment and care for wellbeing (i.e., self-compassionate engagement) and committed actions to try to alleviate and prevent one’s suffering (i.e., self-compassionate action). Our results go beyond those of an earlier version of the CMT-T where improvements in self-compassion [as measured by the Self-Compassion Scale, SCS; 122] were only significant with increased practice of the techniques introduced [and not just session attendance), as supported by the qualitative analyses [32]. Furthermore, these findings are also in support of studies using CMT in other professions that found significant increases in self-compassion (as measured by the SCS) in health care educators and providers [68], mental health professionals [69], psychotherapy students [73], and firefighters [72]. The CMT-T also targets the cultivation of compassion for others [58,61], and participants in the CMT-T group revealed significant increases in compassion to others motivation and action (as measured by the CMAS) and a significant reduction in fears of compassion for others, from pre to post-intervention, with medium to large effect sizes. These findings partially support our hypotheses and indicate that the CMT-T seems to reduce teachers’ fears, blocks and resistances of being compassionate to others while also promoting their motivation, distress tolerance, and commitment to act in compassionate ways towards others. Even though there was a trend towards positive change in compassion for others engagement and action (as measured by the CEAS), this increase did not reach the threshold of significance, contrarily to what was found in the CMT-T pilot study [87]. This finding might be attributable to a ceiling effect, which has been reported in previous studies with this measure [93] and using CMT in community samples [66,67] as participants’ baseline scores were higher in compassion for others, in comparison to the other two flows of compassion, which might be related to a social PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 23 / 36 desirability bias. In fact, results from the stepped wedge analyses support this hypothesis and show that, after receiving the CMT-T intervention, WLC participants also exhibited significant increases in compassion for others (as measured by the CEAS) as well as in compassion to others motivation and action and significant decreases in fears of compassion for others. A more in-depth observation of these findings revealed that even though the post-intervention scores of the CMT-T and the WLC participants who received the intervention between T2 and T3 were similar, the former presented baseline levels higher than the pre-intervention scores of the latter. In fact, in group comparisons analyses, the WLC group showed a significant decrease in compassion for others between baseline and pre-intervention (with a medium effect size). This was an unexpected finding, which might be related to the elevated baseline scores in this measure and to the parallel increase in burnout levels in these WLC participants. As a whole, the present results add to prior CMT studies with teachers where this flow of compassion was not specifically evaluated using a recognised quantitative measure [32] and with other professions [e.g., healthcare educators and professionals, 68,69; fire service personnel, 72]. In regard to changes in compassion from others, teachers in the CMT-T group significantly decreased their fears of receiving compassion from others (with a medium effect size), although no significant differences were found in compassion received from others as measured by the CEAS, which assesses how one perceives other people’s motivation and ability to engage with one’s suffering and to take action to alleviate one’s distress. Stepped wedge analyses further add to these results, revealing significant increases in the perception of compassion received from others (as measured by the CEAS) and reductions in fears of compassion from others. These findings extend the ones described in the CMT-T pilot study [87], where neither compassion from others nor fears of receiving compassion from others significantly changed from preto post-intervention. In the current study, and as expected, the CMT-T produced a reduction in teachers’ inhibitors and resistances to being the recipient of compassion from others which is related to an improvement in one’s ability to be open and willing to receive compassion from others. Mixed results regarding CMT-T induced increases in the perception of others being more compassionate towards the self in this study warrant further exploration. Overall, our results are aligned with previous studies using CMT in community samples [66, 67] and add to preceding research implementing CMT with teachers [32,91] and other professionals [68–70,72,73] that did not assess this flow of compassion. An important aspect of the CFT/CMT approach is the consideration of the inter-relationship between the three flows of compassion (CEAS: compassion for others, being open to compassion from others, and self-compassion). In line with our hypothesis, results showed that the association between the three flows of compassion was strengthened after the CMT-T implementation. These data highlight that CMT-T seems to enhance the general level of several components of the three flows of compassion and reinforce engenderment of a compassionate mind in which higher scores in one flow of compassion tend to be accompanied by higher scores in another flow. These results are analogous to previous research exploring CMT in the general population [e.g., 66,67] and provide further support to the assumption that CMT stimulates the caring motivational system, which facilitates one’s openness and motivation [58,66,116]. Taken together these results and the specificity of the target population, this study provides evidence for the effectiveness of the CMT-T in reducing teachers’ fears, blocks and resistances to compassion (for self, for others and from others) while also facilitating their motivation, distress tolerance and commitment to be compassionate towards themselves and others, along with developing the attributes and practicing the competencies of self-compassion and compassion for others. Therefore, the CMT-T may contribute to attenuating the barriers to compassion and strengthening teachers’ compassionate mind and abilities, including greater selfPLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 24 / 36 compassion, openness to receiving compassion and support from others, and motivation and competencies to establish more compassionate relationships, particularly in the school environment (e.g., colleagues, staff, pupils). One of the central aims of CMT-T is to promote both overall and professional wellbeing, which in the current study were assessed through types of positive affect, linked to feelings of relaxation and calmness, feelings of safeness and contentment, and energised positive emotions (e.g., excited, energised, enthusiastic), and through teachers’ satisfaction with their professional life. Group comparisons revealed that the CMT-T group significantly increased safe, relaxed and activated positive affect from preto post-intervention, with large effect sizes. Stepped wedge analyses further substantiated these findings and revealed that, at post-intervention, WLC participants who completed the CMT-T presented incremented levels of feelings of safeness and relaxation (with large effect sizes) and of vitality/activation (medium effect sizes). These results are in line with our hypotheses and with preceding research that reported increases in positive affect, particularly in feelings of safeness, contentment, and relaxation, after a CMT intervention in community samples [66,67]. Conversely to these previous studies where no changes were found in activated positive affect, interestingly, the CMT-T produced enhanced energizing positive emotions (e.g., excitement, vitality and enthusiasm) hypothesized to be related to the drive system, in addition to heightened positive emotions of safeness, contentment, calmness and relaxation, hypothesized to be related to the soothing system [58, 116]. These findings support the CFT framework regarding the beneficial impact of fostering compassion and reducing its inhibitors on cultivating types of positive affect linked to the affiliative and care-giving mentalities [58,116]. Moreover, it may be that the specificity of the setting where CMT-T was implemented facilitates the promotion of a different type of active positive emotions related to the drive resource-seeking system [58,116]. This may be related to the fact that teachers tend to suffer from burnout and exhaustion [4], which may be reflected in a dampening of this energizing positive affect prior to the intervention. Hence, the fact that CMT-T is applied to their professional lives and within the school context may encourage an adaptive stimulation of the drive resource-seeking system and foster this type of positive energizing emotions which, balanced by the promotion of feelings of safeness and relaxation, may be crucial to professional performance and wellbeing. In fact, this hypothesis seems to be further supported by the results using a new measure assessing emotional climate at work (i.e., the activation of the safeness, drive and threat affect systems) in a subsample of teachers. These participants exhibited significant increases in positive emotions linked to soothing/safeness and drive/vitality at work from pre-to-post CMT-T, representing medium to large effect sizes. Regarding teachers’ satisfaction with professional life, no significant changes were found in the CMT-T group. However, stepped wedge analyses revealed significant increases between baseline (T1) and post-intervention (T3) in the WLC participants who received the CMT-T (medium effect size). Of note, in the group comparison analyses, the WLC group presented a significant increase in satisfaction with professional life from T1 to T2. However, at baseline, these participants had lower scores in satisfaction with professional life than the CMT-T group, and this increase put both groups at a similar level at T2. As a whole, these results concerning the valuable effects of CMT-T on overall and professional wellbeing extend previous studies using earlier versions of CMT-T that did not assess these indicators [32,87] and findings from research using CFT as guided self-help in the general population that demonstrated improvements in wellbeing at post-intervention [79]. Alongside the cultivation of positive emotions and wellbeing, the CMT-T also aims to target and reduce suffering and psychological distress. Although no significant interaction effects were found for outcome measures of psychological distress, within-group comparisons revealed that teachers in the CMT-T group demonstrated significantly decreased anxiety and PLOS ONE Compassionate Mind Training for Teachers PLOS ONE | https://doi.org/10.1371/journal.pone.0263480 March 1, 2022 25 / 36 28. Viac C, Fraser P. Teachers’ well-being: A framework for data collection and analysis. 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