Work Engagement and Well-being Study (SWELL): a randomised controlled feasibility trial evaluating the effects of mindfulness versus light physical exercise at work.

BACKGROUND: Mindfulness-based programmes (MBPs) are increasingly offered at work, often in online self-guided format. However, the evidence on MBPs' effect on work performance (WP) is inconsistent. OBJECTIVE: This pragmatic randomised controlled feasibility trial assessed procedural uncertainties, intervention acceptability and preliminary effect sizes of an MBP on WP, relative to an alternative intervention. METHODS: 241 employees from eight employers were randomised (1:1) to complete a 4-week, self-guided, online MBP or a light physical exercise programme (LE)(active control). Feasibility and acceptability measures were of primary interest. WP at postintervention (PostInt) was the primary outcome for preliminary assessment of effect sizes. Secondary outcomes assessed mental health (MH) and cognitive processes hypothesised to be targeted by the MBP. Outcomes were collected at baseline, PostInt and 12-week follow-up (12wFUP). Prospective trial protocol: NCT04631302. FINDINGS: 87% of randomised participants started the course. Courses had high acceptability. Retention rates were typical for online trials (64% PostInt; 30% 12wFUP). MBP, compared with the LE control, offered negligible benefits for WP (PostInt (d=0.06, 95% CI -0.19 to 0.32); 12wFUP (d=0.02, 95% CI -0.30 to 0.26)). Both interventions improved MH outcomes (ds=-0.40 to 0.58, 95% CI -0.32 to 0.18); between-group differences were small (ds=-0.09 to 0.04, 95% CI -0.15 to 0.17). CONCLUSION: The trial is feasible; interventions are acceptable. Results provide little support for a later phase trial comparing an MBP to a light exercise control. To inform future trials, we summarise procedural challenges. CLINICAL IMPLICATIONS: Results suggest MBPs are unlikely to improve WP relative to light physical exercise. Although the MBP improved MH, other active interventions may be just as efficacious. TRIAL REGISTRATION NUMBER: NCT04631302.

Individual participant data systematic review and meta-analysis of randomised controlled trials assessing adult mindfulness-based programmes for mental health promotion in non-clinical settings.

Introduction: Mindfulness-based programmes (MBPs) are widely used to prevent mental ill-health that is becoming the leading global cause of morbidity. Evidence suggests beneficial average effects but wide variability. We aimed to confirm the effect of MBPs on psychological distress, and to understand whether and how baseline distress, gender, age, education, and dispositional mindfulness modify the effect of MBPs on distress among adults in non-clinical settings. Methods: We conducted a pre-registered systematic review and individual participant data (IPD) meta-analysis (PROSPERO CRD42020200117). Thirteen databases were searched in December 2020 for randomised controlled trials satisfying a quality threshold and comparing in-person, expert-defined MBPs in non-clinical settings with passive control groups. Two researchers independently selected, extracted, and appraised trials using the revised Cochrane Risk-of-Bias Tool (RoB2). Anonymised IPD of eligible trials were sought from collaborating authors. The primary outcome was psychological distress (unpleasant mental or emotional experiences including anxiety and depression) at 1 to 6 months after programme completion. Data were checked and imputed if missing. Pairwise, random-effects, two-stage IPD meta-analyses were conducted. Effect modification analyses followed a within-studies approach. Public and professional stakeholders were involved in the planning, conduct and dissemination of this study. Results: Fifteen trials were eligible, 13 trialists shared IPD (2,371 participants representing 8 countries, median age 34 years-old, 71% women, moderately distressed on average, 20% missing outcome data). In comparison with passive control groups, MBPs reduced average distress between one- and six-months post-intervention with a small to moderate effect size (standardised mean difference (SMD) -0.32; 95% confidence interval (CI) -0.41 to -0.24; p-value < 0.001; 95% prediction interval (PI) -0.41 to -0.24 (no heterogeneity)). Results were robust to sensitivity analyses, and similar for the other psychological distress time point ranges. Confidence in the primary outcome result is high. We found no clear indication that this effect is modified by baseline psychological distress, gender, age, education level, or dispositional mindfulness. Conclusions: Group-based teacher-led MBPs generally reduce psychological distress among community adults who volunteer to receive this type of intervention. More research is needed to identify sources of variability in outcomes at an individual level.

Do Adolescents Like School-Based Mindfulness Training? Predictors of Mindfulness Practice and Responsiveness in the MYRIAD Trial.

OBJECTIVE: We explored what predicts secondary school students' mindfulness practice and responsiveness to universal school-based mindfulness training (SBMT), and how students experience SBMT. METHOD: A mixed-methods design was used. Participants were 4,232 students (11-13 years of age), in 43 UK secondary schools, who received universal SBMT (ie, ".b" program), within the MYRIAD trial (ISRCTN86619085). Following previous research, student, teacher, school, and implementation factors were evaluated as potential predictors of students' out-of-school mindfulness practice and responsiveness (ie, interest in and attitudes toward SBMT), using mixed-effects linear regression. We explored pupils' SBMT experiences using thematic content analysis of their answers to 2 free-response questions, 1 question focused on positive experiences and 1 question on difficulties/challenges. RESULTS: Students reported practicing out-of-school mindfulness exercises on average once during the intervention (mean [SD] = 1.16 [1.07]; range, 0-5). Students' average ratings of responsiveness were intermediate (mean [SD] = 4.72 [2.88]; range, 0-10). Girls reported more responsiveness. High risk of mental health problems was associated with lower responsiveness. Asian ethnicity and higher school-level economic deprivation were related to greater responsiveness. More SBMT sessions and better quality of delivery were associated with both greater mindfulness practice and responsiveness. In terms of students' experiences of SBMT, the most frequent themes (60% of the minimally elaborated responses) were an increased awareness of bodily feelings/sensations and increased ability to regulate emotions. CONCLUSION: Most students did not engage with mindfulness practice. Although responsiveness to the SMBT was intermediate on average, there was substantial variation, with some youth rating it negatively and others rating it positively. Future SBMT developers should consider co-designing curricula with students, carefully assessing the student characteristics, aspects of the school environment, and implementation factors associated with mindfulness practice and responsiveness. SBMT teacher training is key, as more observed proficiency in SBMT teaching is associated with greater student mindfulness practice and responsiveness to SBMT.

Susceptibility to prosocial and antisocial influence in adolescence following mindfulness training.

Mindfulness training programmes have shown to encourage prosocial behaviours and reduce antisocial tendencies in adolescents. However, less is known about whether training affects susceptibility to prosocial and antisocial influence. The current study investigated the effect of mindfulness training (compared with an active control) on self-reported prosocial and antisocial tendencies and susceptibility to prosocial and antisocial influence. 465 adolescents aged 11-16 years were randomly allocated to one of two training programmes. Pre- and post-training, participants completed a social influence task. Self-reported likelihood of engaging in prosocial and antisocial behaviours did not change post-training, and regardless of training group, participants showed a higher propensity for prosocial influence than for antisocial influence. Finally, participants were less influenced by antisocial ratings following both training programmes.

The development and internal evaluation of a predictive model to identify for whom Mindfulness-Based Cognitive Therapy (MBCT) offers superior relapse prevention for recurrent depression versus maintenance antidepressant medication.

Depression is highly recurrent, even following successful pharmacological and/or psychological intervention. We aimed to develop clinical prediction models to inform adults with recurrent depression choosing between antidepressant medication (ADM) maintenance or switching to Mindfulness-Based Cognitive Therapy (MBCT). Using data from the PREVENT trial (N=424), we constructed prognostic models using elastic net regression that combined demographic, clinical and psychological factors to predict relapse at 24 months under ADM or MBCT. Only the ADM model (discrimination performance: AUC=.68) predicted relapse better than baseline depression severity (AUC=.54; one-tailed DeLong's test: z=2.8, p=.003). Individuals with the poorest ADM prognoses who switched to MBCT had better outcomes compared to those who maintained ADM (48% vs. 70% relapse, respectively; superior survival times [z=-2.7, p=.008]). For individuals with moderate-to-good ADM prognosis, both treatments resulted in similar likelihood of relapse. If replicated, the results suggest that predictive modeling can inform clinical decision-making around relapse prevention in recurrent depression.

Do mindfulness-based programmes improve the cognitive skills, behaviour and mental health of children and adolescents? An updated meta-analysis of randomised controlled trials.

QUESTION: Mindfulness-based programmes (MBPs) are an increasingly popular approach to improving mental health in young people. Our previous meta-analysis suggested that MBPs show promising effectiveness, but highlighted a lack of high-quality, adequately powered randomised controlled trials (RCTs). This updated meta-analysis assesses the-state-of the-art of MBPs for young people in light of new studies. It explores MBP's effectiveness in active vs passive controls; selective versus universal interventions; and studies that included follow-up. STUDY SELECTION AND ANALYSIS: We searched for published and unpublished RCTs of MBPs with young people (<19 years) in PubMed Central, PsycINFO, Web of Science, EMBASE, ICTRP, ClinicalTrials.gov, EThOS, EBSCO and Google Scholar. Random-effects meta-analyses were conducted, and standardised mean differences (Cohen's d) were calculated. FINDINGS: Sixty-six RCTs, involving 20 138 participants (9552 receiving an MBP and 10 586 controls), were identified. Compared with passive controls, MBPs were effective in improving anxiety/stress, attention, executive functioning, and negative and social behaviour (d from 0.12 to 0.35). Compared against active controls, MBPs were more effective in reducing anxiety/stress and improving mindfulness (d=0.11 and 0.24, respectively). In studies with a follow-up, there were no significant positive effects of MBPs. No consistent pattern favoured MBPs as a universal versus selective intervention. CONCLUSIONS: The enthusiasm for MBPs in youth has arguably run ahead of the evidence. While MBPs show promising results for some outcomes, in general, the evidence is of low quality and inconclusive. We discuss a conceptual model and the theory-driven innovation required to realise the potential of MBPs in supporting youth mental health.

Effectiveness of universal school-based mindfulness training compared with normal school provision on teacher mental health and school climate: results of the MYRIAD cluster randomised controlled trial.

BACKGROUND: Education is broader than academic teaching. It includes teaching students social-emotional skills both directly and indirectly through a positive school climate. OBJECTIVE: To evaluate if a universal school-based mindfulness training (SBMT) enhances teacher mental health and school climate. METHODS: The My Resilience in Adolescence parallel group, cluster randomised controlled trial (registration: ISRCTN86619085; funding: Wellcome Trust (WT104908/Z/14/Z, WT107496/Z/15/Z)) recruited 85 schools (679 teachers) delivering social and emotional teaching across the UK. Schools (clusters) were randomised 1:1 to either continue this provision (teaching as usual (TAU)) or include universal SBMT. Data on teacher mental health and school climate were collected at prerandomisation, postpersonal mindfulness and SBMT teacher training, after delivering SBMT to students, and at 1-year follow-up. FINDING: Schools were recruited in academic years 2016/2017 and 2017/2018. Primary analysis (SBMT: 43 schools/362 teachers; TAU: 41 schools/310 teachers) showed that after delivering SBMT to students, SBMT versus TAU enhanced teachers' mental health (burnout) and school climate. Adjusted standardised mean differences (SBMT minus TAU) were: exhaustion (-0.22; 95% CI -0.38 to -0.05); personal accomplishment (-0.21; -0.41, -0.02); school leadership (0.24; 0.04, 0.44); and respectful climate (0.26; 0.06, 0.47). Effects on burnout were not significant at 1-year follow-up. Effects on school climate were maintained only for respectful climate. No SBMT-related serious adverse events were reported. CONCLUSIONS: SBMT supports short-term changes in teacher burnout and school climate. Further work is required to explore how best to sustain improvements. CLINICAL IMPLICATIONS: SBMT has limited effects on teachers' mental and school climate. Innovative approaches to support and preserve teachers' mental health and school climate are needed.

The impact of mindfulness training in early adolescence on affective executive control, and on later mental health during the COVID-19 pandemic: a randomised controlled trial.

BACKGROUND: Previous research suggests that mindfulness training (MT) appears effective at improving mental health in young people. MT is proposed to work through improving executive control in affectively laden contexts. However, it is unclear whether MT improves such control in young people. MT appears to mitigate mental health difficulties during periods of stress, but any mitigating effects against COVID-related difficulties remain unexamined. OBJECTIVE: To evaluate whether MT (intervention) versus psychoeducation (Psy-Ed; control), implemented in after-school classes: (1) Improves affective executive control; and/or (2) Mitigates negative mental health impacts from the COVID-19 pandemic. METHODS: A parallel randomised controlled trial (RCT) was conducted (Registration: https://osf.io/d6y9q/; Funding: Wellcome (WT104908/Z/14/Z, WT107496/Z/15/Z)). 460 students aged 11-16 years were recruited and randomised 1:1 to either MT (N=235) or Psy-Ed (N=225) and assessed preintervention and postintervention on experimental tasks and self-report inventories of affective executive control. The RCT was then extended to evaluate protective functions of MT on mental health assessed after the first UK COVID-19 lockdown. FINDINGS: Results provided no evidence that the version of MT used here improved affective executive control after training or mitigated negative consequences on mental health of the COVID-19 pandemic relative to Psy-Ed. No adverse events were reported. CONCLUSIONS: There is no evidence that MT improves affective control or downstream mental health of young people during stressful periods. CLINICAL IMPLICATIONS: We need to identify interventions that can enhance affective control and thereby young people's mental health.

School-based mindfulness training in early adolescence: what works, for whom and how in the MYRIAD trial?

BACKGROUND: Preventing mental health problems in early adolescence is a priority. School-based mindfulness training (SBMT) is an approach with mixed evidence. OBJECTIVES: To explore for whom SBMT does/does not work and what influences outcomes. METHODS: The My Resilience in Adolescence was a parallel-group, cluster randomised controlled trial (K=84 secondary schools; n=8376 students, age: 11-13) recruiting schools that provided standard social-emotional learning. Schools were randomised 1:1 to continue this provision (control/teaching as usual (TAU)), and/or to offer SBMT ('.b' (intervention)). Risk of depression, social-emotional-behavioural functioning and well-being were measured at baseline, preintervention, post intervention and 1 year follow-up. Hypothesised moderators, implementation factors and mediators were analysed using mixed effects linear regressions, instrumental variable methods and path analysis. FINDINGS: SBMT versus TAU resulted in worse scores on risk of depression and well-being in students at risk of mental health problems both at post intervention and 1-year follow-up, but differences were small and not clinically relevant. Higher dose and reach were associated with worse social-emotional-behavioural functioning at postintervention. No implementation factors were associated with outcomes at 1-year follow-up. Pregains-postgains in mindfulness skills and executive function predicted better outcomes at 1-year follow-up, but the SBMT was unsuccessful to teach these skills with clinical relevance.SBMT as delivered in this trial is not indicated as a universal intervention. Moreover, it may be contraindicated for students with existing/emerging mental health symptoms. CLINICAL IMPLICATIONS: Universal SBMT is not recommended in this format in early adolescence. Future research should explore social-emotional learning programmes adapted to the unique needs of young people.

Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial.

BACKGROUND: Systematic reviews suggest school-based mindfulness training (SBMT) shows promise in promoting student mental health. OBJECTIVE: The My Resilience in Adolescence (MYRIAD) Trial evaluated the effectiveness and cost-effectiveness of SBMT compared with teaching-as-usual (TAU). METHODS: MYRIAD was a parallel group, cluster-randomised controlled trial. Eighty-five eligible schools consented and were randomised 1:1 to TAU (43 schools, 4232 students) or SBMT (42 schools, 4144 students), stratified by school size, quality, type, deprivation and region. Schools and students (mean (SD); age range=12.2 (0.6); 11-14 years) were broadly UK population-representative. Forty-three schools (n=3678 pupils; 86.9%) delivering SBMT, and 41 schools (n=3572; 86.2%) delivering TAU, provided primary end-point data. SBMT comprised 10 lessons of psychoeducation and mindfulness practices. TAU comprised standard social-emotional teaching. Participant-level risk for depression, social-emotional-behavioural functioning and well-being at 1 year follow-up were the co-primary outcomes. Secondary and economic outcomes were included. FINDINGS: Analysis of 84 schools (n=8376 participants) found no evidence that SBMT was superior to TAU at 1 year. Standardised mean differences (intervention minus control) were: 0.005 (95% CI -0.05 to 0.06) for risk for depression; 0.02 (-0.02 to 0.07) for social-emotional-behavioural functioning; and 0.02 (-0.03 to 0.07) for well-being. SBMT had a high probability of cost-effectiveness (83%) at a willingness-to-pay threshold of £20 000 per quality-adjusted life year. No intervention-related adverse events were observed. CONCLUSIONS: Findings do not support the superiority of SBMT over TAU in promoting mental health in adolescence. CLINICAL IMPLICATIONS: There is need to ask what works, for whom and how, as well as considering key contextual and implementation factors. TRIAL REGISTRATION: Current controlled trials ISRCTN86619085. This research was funded by the Wellcome Trust (WT104908/Z/14/Z and WT107496/Z/15/Z).

Mindfulness-based programmes for mental health promotion in adults in non-clinical settings: protocol of an individual participant data meta-analysis of randomised controlled trials.

INTRODUCTION: With mental ill health listed as a top cause of global disease burden, there is an urgent need to prioritise mental health promotion programmes. Mindfulness-based programmes (MBPs) are being widely implemented to reduce stress in non-clinical settings. In a recent aggregate-level meta-analysis we found that, compared with no intervention, these MBPs reduce average psychological distress. However, heterogeneity between studies impedes generalisation of effects across every setting. Study-level effect modifiers were insufficient to reduce heterogeneity; studying individual-level effect modifiers is warranted. This requires individual participant data (IPD) and larger samples than those found in existing individual trials. METHODS AND ANALYSIS: We propose an IPD meta-analysis. Our primary aim is to see if, and how, baseline psychological distress, gender, age, education and dispositional mindfulness moderate the effect of MBPs on distress. We will search 13 databases for good-quality randomised controlled trials comparing in-person, expert-defined MBPs in non-clinical settings with passive controls. Two researchers will independently select, extract and appraise trials using the revised Cochrane risk-of-bias tool. Anonymised IPD of eligible trials will be sought from authors, who will be invited to collaborate.The primary outcome will be psychological distress measured using psychometrically validated questionnaires at 1-6 months after programme completion. Pairwise random-effects two-stage IPD meta-analyses will be conducted. Moderator analyses will follow a 'deft' approach. We will estimate subgroup-specific intervention effects. Secondary outcomes and sensitivity analyses are prespecified. Multiple imputation strategies will be applied to missing data. ETHICS AND DISSEMINATION: The findings will refine our knowledge on the effectiveness of MBPs and help improve the targeting of MBPs in non-clinical settings. They will be shared in accessible formats with a range of stakeholders. Public and professional stakeholders are being involved in the planning, conduct and dissemination of this project. PROSPERO REGISTRATION NUMBER: CRD42020200117.

Protocol for the Work Engagement and Well-being Study (SWELL): a randomised controlled feasibility trial evaluating the effects of mindfulness versus light physical exercise at work.

INTRODUCTION: Mental ill health is a major cause of disability. Workplaces are attractive for preventative interventions since most adults work; meanwhile, employers are interested in improving employees' well-being and productivity. Mindfulness-based programmes are increasingly popular in occupational settings. However, there is inconsistent evidence whether mindfulness interventions improve work performance and how effective mindfulness-based programmes are, compared with other interventions, in preventing mental ill health. METHODS AND ANALYSIS: In this online randomised controlled feasibility trial, an anticipated 240 employees will be randomised to either a 4-week light physical exercise course or a mindfulness course of the same duration (1:1 allocation). The primary outcome is work performance, measured using the Work Role Functioning Questionnaire. We aim to evaluate the acceptability, feasibility and procedural uncertainties of a randomised controlled trial in a workplace, calculate an effect size estimate to inform power calculations for a larger trial, and explore whether improved executive function and/or enhanced mental health could be potential mechanisms underlying the effect of mindfulness on work performance. Outcomes will be collected at baseline, postintervention and 12-week follow-up. ETHICS AND DISSEMINATION: Approval has been obtained from Cambridge Psychology Research Ethics Committee. (PRE.2020072). Results will be published in peer-reviewed journals. A lay summary will be disseminated to a wider audience including participating employers. TRIAL REGISTRATION NUMBER: NCT04631302.

Universal Mindfulness Training in Schools for Adolescents: a Scoping Review and Conceptual Model of Moderators, Mediators, and Implementation Factors.

There is evidence that universal school-based mindfulness training (SBMT) can have positive effects for young people. However, it is unknown who benefits most from such training, how training exerts effects, and how implementation impacts effects. This study aimed to provide an overview of the evidence on the mediators, moderators, and implementation factors of SBMT, and propose a conceptual model that can be used both to summarize the evidence and provide a framework for future research. A scoping review was performed, and six databases and grey literature were searched. Inclusion and exclusion criteria were applied to select relevant material. Quantitative and qualitative information was extracted from eligible articles and reported in accordance with PRISMA-ScR guidelines. The search produced 5479 articles, of which 31 were eligible and included in the review. Eleven studies assessed moderators of SBMT on pupil outcomes, with mixed findings for all variables tested. Five studies examined the mediating effect of specific variables on pupil outcomes, with evidence that increases in mindfulness skills and decreases in cognitive reactivity and self-criticism post-intervention are related to better pupil outcomes at follow-up. Twenty-five studies assessed implementation factors. We discuss key methodological shortcomings of included studies and integrate our findings with existing implementation frameworks to propose a conceptual model. Widespread interest in universal SBMT has led to increased research over recent years, exploring who SBMT works for and how it might work, but the current evidence is limited. We make recommendations for future research and provide a conceptual model to guide theory-led developments.

Autobiographical memory style and clinical outcomes following mindfulness-based cognitive therapy (MBCT): An individual patient data meta-analysis.

The ability to retrieve specific, single-incident autobiographical memories has been consistently posited as a predictor of recurrent depression. Elucidating the role of autobiographical memory specificity in patient-response to depressive treatments may improve treatment efficacy and facilitate use of science-driven interventions. We used recent methodological advances in individual patient data meta-analysis to determine a) whether memory specificity is improved following mindfulness-based cognitive therapy (MBCT), relative to control interventions, and b) whether pre-treatment memory specificity moderates treatment response. All bar one study evaluated MBCT for relapse prevention for depression. Our initial analysis therefore focussed on MBCT datasets only(n = 708), then were repeated including the additional dataset(n = 880). Memory specificity did not significantly differ from baseline to post-treatment for either MBCT and Control interventions. There was no evidence that baseline memory specificity predicted treatment response in terms of symptom-levels, or risk of relapse. Findings raise important questions regarding the role of memory specificity in depressive treatments.

Teachers "Finding Peace in a Frantic World": An Experimental Study of Self-Taught and Instructor-Led Mindfulness Program Formats on Acceptability, Effectiveness, and Mechanisms.

Mindfulness training (MT) is considered appropriate for school teachers and enhances well-being. Most research has investigated the efficacy of instructor-led MT. However, little is known about the benefits of using self-taught formats, nor what the key mechanisms of change are that contribute to enhanced teacher well-being. This study compared instructor-led and self-taught MT based on a book (Williams & Penman, 2011) in a sample of secondary school teachers. We assessed expectancy, the degree to which participants believed the intervention was effective, their program engagement, well-being and psychological distress, and evaluated whether mindfulness and self-compassion skills acted as mediators of outcomes. In total, 206 teachers from 43 schools were randomized by school to an instructor-led or self-taught course-77% female, mean age 39 years (SD = 9.0). Both MT formats showed similar rates of participant expectancy and engagement, but the instructor-led arm was perceived as more credible. Using linear mixed-effects models, we found the self-taught arm showed significant pre-post improvements in self-compassion and well-being, while the instructor-led arm showed such improvements in mindfulness, self-compassion, well-being, perceived stress, anxiety, depression, and burnout. Changes over time significantly differed between the groups in all these outcomes, favoring the instructor-led arm. The instructor-led arm, compared with the self-taught, indirectly improved teacher outcomes by enhancing mindfulness and self-compassion as mediating factors. Mindfulness practice frequency had indirect effects on teacher outcomes through mindfulness in both self-taught and instructor-led arms. Our results suggest both formats are considered reasonable, but the instructor-led is more effective than the self-taught. Trial registration: ISRCTN18013311.

Update to the effectiveness and cost-effectiveness of a mindfulness training programme in schools compared with normal school provision (MYRIAD): study protocol for a randomised controlled trial.

BACKGROUND: MYRIAD (My Resilience in Adolescence) is a superiority, parallel group, cluster randomised controlled trial designed to examine the effectiveness and cost-effectiveness of a mindfulness training (MT) programme, compared with normal social and emotional learning (SEL) school provision to enhance mental health, social-emotional-behavioural functioning and well-being in adolescence. The original trial protocol was published in Trials (accessible at https://doi.org/10.1186/s13063-017-1917-4 ). This included recruitment in two cohorts, enabling the learning from the smaller first cohort to be incorporated in the second cohort. Here we describe final amendments to the study protocol and discuss their underlying rationale. METHODS: Four major changes were introduced into the study protocol: (1) there were changes in eligibility criteria, including a clearer operational definition to assess the degree of SEL implementation in schools, and also new criteria to avoid experimental contamination; (2) the number of schools and pupils that had to be recruited was increased based on what we learned in the first cohort; (3) some changes were made to the secondary outcome measures to improve their validity and ability to measure constructs of interest and to reduce the burden on school staff; and (4) the current Coronavirus Disease 2019 (SARS-CoV-2 or COVID-19) pandemic both influences and makes it difficult to interpret the 2-year follow-up primary endpoint results, so we changed our primary endpoint to 1-year follow-up. DISCUSSION: These changes to the study protocol were approved by the Trial Management Group, Trial Steering Committee and Data and Ethics Monitoring Committees and improved the enrolment of participants and quality of measures. Furthermore, the change in the primary endpoint will give a more reliable answer to our primary question because it was collected prior to the COVID-19 pandemic in both cohort 1 and cohort 2. Nevertheless, the longer 2-year follow-up data will still be acquired, although this time-point will be now framed as a second major investigation to answer some new important questions presented by the combination of the pandemic and our study design. TRIAL REGISTRATION: International Standard Randomised Controlled Trials ISRCTN86619085 . Registered on 3 June 2016.

The Role of Schools in Early Adolescents' Mental Health: Findings From the MYRIAD Study.

OBJECTIVE: Recent studies suggest mental health in youths is deteriorating. The current policy in the United Kingdom emphasizes the role of schools for mental health promotion and prevention, but little data exist on what aspects of schools influence mental health in pupils. This study explored school-level influences on the mental health of young people in a large school-based sample from the United Kingdom. METHOD: Baseline data from a large cluster randomized controlled trial collected between 2016 and 2018 from mainstream secondary schools selected to be representative in relation to their quality rating, size, deprivation, mixed or single-sex pupil population, and country were analyzed. Participants were pupils in their first or second year of secondary school. The study assessed whether school-level factors were associated with pupil mental health. RESULTS: The study included 26,885 pupils (response rate = 90%; age range, 11‒14 years; 55% female) attending 85 schools in the United Kingdom. Schools accounted for 2.4% (95% CI: 2.0%‒2.8%; p < .0001) of the variation in psychopathology, 1.6% (95% CI: 1.2%‒2.1%; p < .0001) of depression, and 1.4% (95% CI: 1.0%‒1.7%; p < .0001) of well-being. Schools in urban locations, with a higher percentage of free school meals and of White British, were associated with poorer pupil mental health. A more positive school climate was associated with better mental health. CONCLUSION: School-level variables, primarily related to contextual factors, characteristics of pupil population, and school climate, explain a small but significant amount of variability in mental health of young people. This information might be used to identify schools that are in need of more resources to support mental health of young people. CLINICAL TRIAL REGISTRATION INFORMATION: MYRIAD: My Resilience in Adolescence, a Study Examining the Effectiveness and Cost-Effectiveness of a Mindfulness Training Programme in Schools Compared With Normal School Provision; https://www.isrctn.com/; 86619085.

Mindfulness-based programmes for mental health promotion in adults in nonclinical settings: A systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: There is an urgent need for mental health promotion in nonclinical settings. Mindfulness-based programmes (MBPs) are being widely implemented to reduce stress, but a comprehensive evidence synthesis is lacking. We reviewed trials to assess whether MBPs promote mental health relative to no intervention or comparator interventions. METHODS AND FINDINGS: Following a detailed preregistered protocol (PROSPERO CRD42018105213) developed with public and professional stakeholders, 13 databases were searched to August 2020 for randomised controlled trials (RCTs) examining in-person, expert-defined MBPs in nonclinical settings. Two researchers independently selected, extracted, and appraised trials using the Cochrane Risk-of-Bias Tool 2.0. Primary outcomes were psychometrically validated anxiety, depression, psychological distress, and mental well-being questionnaires at 1 to 6 months after programme completion. Multiple testing was performed using p < 0.0125 (Bonferroni) for statistical significance. Secondary outcomes, meta-regression and sensitivity analyses were prespecified. Pairwise random-effects multivariate meta-analyses and prediction intervals (PIs) were calculated. A total of 11,605 participants in 136 trials were included (29 countries, 77% women, age range 18 to 73 years). Compared with no intervention, in most but not all scenarios MBPs improved average anxiety (8 trials; standardised mean difference (SMD) = -0.56; 95% confidence interval (CI) -0.80 to -0.33; p-value < 0.001; 95% PI -1.19 to 0.06), depression (14 trials; SMD = -0.53; 95% CI -0.72 to -0.34; p-value < 0.001; 95% PI -1.14 to 0.07), distress (27 trials; SMD = -0.45; 95% CI -0.58 to -0.31; p-value < 0.001; 95% PI -1.04 to 0.14), and well-being (9 trials; SMD = 0.33; 95% CI 0.11 to 0.54; p-value = 0.003; 95% PI -0.29 to 0.94). Compared with nonspecific active control conditions, in most but not all scenarios MBPs improved average depression (6 trials; SMD = -0.46; 95% CI -0.81 to -0.10; p-value = 0.012, 95% PI -1.57 to 0.66), with no statistically significant evidence for improving anxiety or distress and no reliable data on well-being. Compared with specific active control conditions, there is no statistically significant evidence of MBPs' superiority. Only effects on distress remained when higher-risk trials were excluded. USA-based trials reported smaller effects. MBPs targeted at higher-risk populations had larger effects than universal MBPs. The main limitation of this review is that confidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is moderate to very low, mainly due to inconsistency and high risk of bias in many trials. CONCLUSIONS: Compared with taking no action, MBPs of the included studies promote mental health in nonclinical settings, but given the heterogeneity between studies, the findings do not support generalisation of MBP effects across every setting. MBPs may have specific effects on some common mental health symptoms. Other preventative interventions may be equally effective. Implementation of MBPs in nonclinical settings should be partnered with thorough research to confirm findings and learn which settings are most likely to benefit.

Research Review: The effects of mindfulness-based interventions on cognition and mental health in children and adolescents - a meta-analysis of randomized controlled trials.

BACKGROUND: Mindfulness based interventions (MBIs) are an increasingly popular way of attempting to improve the behavioural, cognitive and mental health outcomes of children and adolescents, though there is a suggestion that enthusiasm has moved ahead of the evidence base. Most evaluations of MBIs are either uncontrolled or nonrandomized trials. This meta-analysis aims to establish the efficacy of MBIs for children and adolescents in studies that have adopted a randomized, controlled trial (RCT) design. METHODS: A systematic literature search of RCTs of MBIs was conducted up to October 2017. Thirty-three independent studies including 3,666 children and adolescents were included in random effects meta-analyses with outcome measures categorized into cognitive, behavioural and emotional factors. Separate random effects meta-analyses were completed for the seventeen studies (n = 1,762) that used an RCT design with an active control condition. RESULTS: Across all RCTs we found significant positive effects of MBIs, relative to controls, for the outcome categories of Mindfulness, Executive Functioning, Attention, Depression, Anxiety/Stress and Negative Behaviours, with small effect sizes (Cohen's d), ranging from .16 to .30. However, when considering only those RCTs with active control groups, significant benefits of an MBI were restricted to the outcomes of Mindfulness (d = .42), Depression (d = .47) and Anxiety/Stress (d = .18) only. CONCLUSIONS: This meta-analysis reinforces the efficacy of using MBIs for improving the mental health and wellbeing of youth as assessed using the gold standard RCT methodology. Future RCT evaluations should incorporate scaled-up definitive trial designs to further evaluate the robustness of MBIs in youth, with an embedded focus on mechanisms of action.

The effectiveness and cost-effectiveness of a mindfulness training programme in schools compared with normal school provision (MYRIAD): study protocol for a randomised controlled trial.

BACKGROUND: Mindfulness-based approaches for adults are effective at enhancing mental health, but few controlled trials have evaluated their effectiveness or cost-effectiveness for young people. The primary aim of this trial is to evaluate the effectiveness and cost-effectiveness of a mindfulness training (MT) programme to enhance mental health, wellbeing and social-emotional behavioural functioning in adolescence. METHODS/DESIGN: To address this aim, the design will be a superiority, cluster randomised controlled, parallel-group trial in which schools offering social and emotional provision in line with good practice (Formby et al., Personal, Social, Health and Economic (PSHE) Education: A mapping study of the prevalent models of delivery and their effectiveness, 2010; OFSTED, Not Yet Good Enough: Personal, Social, Health and Economic Education in schools, 2013) will be randomised to either continue this provision (control) or include MT in this provision (intervention). The study will recruit and randomise 76 schools (clusters) and 5700 school students aged 12 to 14 years, followed up for 2 years. DISCUSSION: The study will contribute to establishing if MT is an effective and cost-effective approach to promoting mental health in adolescence. TRIALS REGISTRATION: International Standard Randomised Controlled Trials, identifier: ISRCTN86619085 . Registered on 3 June 2016.