Introduction

The use and promotion of secular mindfulness practices and mindfulness-based interventions (MBIs) for youth have been increasing in their use across a variety of settings in the USA (e.g., Renshaw & Cook, 2017). Mindfulness has been a Buddhist practice since ancient times, making its way to the Western world as a therapeutic tool only a few decades ago (Sun, 2014). The Western practice of mindfulness is based on the ambiguous, and perhaps flawed, translation of sati as conscience, which then was interpreted as “bare attention.” Introduced by Jon Kabat-Zinn (1994) to the USA, it is described as “paying attention in a particular way: on purpose, in the present moment, and nonjudgmentally” (p. 4). The interpretation of mindfulness as bare attention was quickly accepted by the Western world and many scholars started to operationalize it, while also detaching mindfulness from its Buddhist roots transforming it into secular mindfulness (See Lee, 2018; Marx, 2015; and Sun, 2014 for further readings on the origin of mindfulness and its translation to the Western world).

Historically in the United States, MBIs were used in practice and in research with adults experiencing chronic illness. This work has contributed to the foundational and successful work of various MBI programs such as Mindfulness-Based Stress Reduction (MBSR; Stahl & Goldstein, 2010), Mindfulness-Based Cognitive Therapy (MBCT; Segal et al., 2002), Mindfulness-Based Relapse Prevention (MBPT; Bowen et al., 2021), Dialectical Behavioral Therapy (DBT; Linehan et al., 1993), and Acceptance and Commitment Therapy (ACT; Hayes et al., 1999). Given the success of MBIs for adults, researchers and clinicians have adapted its use for youth (Zenner et al., 2014) and there has been a rise of mindfulness interventions, curricula, and programming within educational contexts (e.g., Bender et al., 2018; Renshaw & Cook, 2017). Within schools, mindfulness has been incorporated into established mental health interventions (e.g., DBT; ACT), school-based social-emotional learning (SEL) curriculum (e.g., Second Step; Committee for Children, 2014), and stand-alone mindfulness skill-building and intervention programs (e.g., MindUP; Maloney et al., 2016). It has also been implemented in schools with educators. In addition to positive outcomes found for youth, a recent systematic review concluded that it is effective in reducing teachers’ stress levels (Emerson et al., 2017).

MBIs in schools have been viewed as techniques that can be used to activate mindfulness processes to improve a specific outcome. More specifically, Renshaw & Cook (2017) conceptualize mindfulness skills as “…specific practices that activate mindfulness processes, such as deep breathing or body scan, for the purpose of achieving an immediate therapeutic effect” (p. 6) and “can refer more broadly to one’s ability to orient attention toward immediate experience and then relate to that experience in a purposeful and positive way, which is not bound by use of particular practices” (p. 6). This conceptualization is important for research and practice, particularly in schools, given that it is framed as a teachable practice.

Outcomes of MBIs are commonly studied for students in schools. For example, MBIs have been implemented with adolescents with Attention-Deficit/ Hyperactivity Disorder (ADHD) symptoms (Tercelli & Ferreira, 2019), minoritized children with depression symptoms (Dunning et al., 2019; Liehr & Diaz, 2010), and children with learning and anxiety disorders (Beauchemin et al., 2008; Odgers et al., 2020) to decrease symptomology and improve quality of life. A recent study conducted by Lemberger-Truelove et al. (2021) found that students who received MBI and social-emotional interventions demonstrated improvements in their tolerance to stress, social curiosity, executive functioning skills, and academic achievement (i.e., mathematics, science, English, and social studies). Furthermore, Felver et al. (2016) reviewed 28 studies of MBIs and found decreased internalized problems (n = 15), decreased externalized problems (n = 6), and improved executive functioning (n = 4) for students. Furthermore, increased prosocial behavior and positive affect were also reported in several studies. Taken together, youth outcomes for MBIs are generally positive and beneficial across multiple skills and domains including behavior, social-emotional functioning, cognitive skills, and school performance.

While outcomes (e.g., improved behavior, improved social-emotional functioning) of MBIs are important to evaluate and have been the primary focus of MBI research in schools, it is also imperative to explore mindfulness constructs (i.e., cognitive reappraisal, present attention, awareness, nonjudgment, emotion regulation; Ma & Fang, 2019) or processes to understand what is activated during intervention. In one recent meta-analysis, Klingbeil et al., (2017a, 2017b) found that only 19.7% of articles measured mindfulness constructs. In these studies, MBIs were associated with increased mindfulness skills (g = 0.510). At the same time, student outcomes included reduced internalized problems (g = 0.39) and externalized problems (g = 0.29), and improved prosocial behavior and social competence (g = 0.36). This review is one of the first meta-analyses to link and examine MBIs, mindfulness constructs, and outcomes of MBIs. Further work in the area of mindfulness constructs is needed. Felver et al. (2016) has noted the lack of detail reported by researchers and the need to further evaluate different aspects of mindfulness implementation to better understand mindfulness as a construct and process.

Erisman & Roemer (2012) define mindfulness process as “the ability to notice when one is not attending to the present moment and repeatedly redirect attention back to open, curious, nonjudgmental present awareness” (p. 694). Examining the processes that may cause the outcome is important as this will aid in understanding the link between process (e.g., awareness, nonjudgment) and outcomes (e.g., lower stress, improved behavior) when implementing MBIs with youth. As Christopher and colleagues (2015) note, the utilization of self-reported mindfulness measures is a way to measure mindfulness processes, rather than behavior measures or grades, as MBI outcomes are often measured for youth in schools. Therefore, one way to improve understanding of mindfulness processes is to examine the measures that capture mindfulness constructs. However, a recent systematic review of school based MBIs over the past 15 years indicated that only about 20% of studies that implement MBIs actually measure mindfulness constructs before, during, or after intervention (Molina Palacios et al., in press), which is consistent with the work of Klingbeil et al., (2017a, 2017b). To adequately and accurately capture what and if mindfulness processes change in intervention, measurement of these constructs (e.g., intention, attention, awareness, nonjudgement) and not just outcomes that are intended as a result of intervention implementation (e.g., depression, anxiety, behavior, academic achievement) are imperative.

Research has demonstrated that mindfulness is predominantly measured via self-report for adults (e.g., Sauer et al., 2013), however, less is known about youth-focused mindfulness measures. In a review conducted by Eklund and colleagues (2017), it was concluded that mindfulness in children and adolescents is often measured directly via self-report given the introspective nature of mindfulness (Eklund et al., 2017); however, this poses challenges for developmentally younger students (Lemberger-Truelove et al., 2021). Less frequently, mindfulness is evaluated indirectly (rated by adults) by examining youth’s skills related to mindfulness (e.g., self-regulation; Zhang et al., 2022) or by observing behavior (e.g., time on task in the classroom; Eklund et al., 2017). In their review, the researchers identified three youth self-report measures including the Child and Adolescent Mindfulness Measure (CAMM; Greco et al., 2011), the Mindful Attention Awareness Scale – Adolescents (MAAS-A; Brown et al., 2011), and the Mindful Thinking and Action Scale for adolescents (MTASA; West et al., 2007).

In another systematic review, Goodman and colleagues (2017) identified seven self-report measures for youth. Of the self-report measures, only four of the scales were published and validated (i.e., CAMM, MAAS-A, MAAS-C, Comprehensive Inventory of Mindfulness Experiences-Adolescent [CHIME-A]), while the other scales were doctoral dissertations, conference presentations (i.e., Mindful Thinking and Action Scale for Adolescents [MTASA], Mindfulness Scale for Pre-Teens, Teens, and Adults [MSPTA]), or described as an experimental measure that has not been psychometrically evaluated (i.e., Mindfulness Inventory for Children and Adolescents [MICA]). Some of the measures listed above measure the mindfulness as a unidimensional construct (no subscales) (CAMM, MAAS-A, MAAS-C), while others measure between four to eight constructs (MTASA, MSPTA, MICA, CHIME-A). Goodman et al. (2017) reported that many of the MBI measures mentioned above did not show strong correlations between scales, which may lead to “items being interpreted differently, or different facets of mindfulness may be assessed by each measure” (Goodman et al., 2017, p. 1416). Additionally, it was reported that although these scales were validated, many of them have limitations in how they measure mindfulness in children and adolescents. Goodman and colleagues (2017) highlighted the importance of continued investigation of measures that evaluate mindfulness for youth. This is important given that reliable and valid measures help to improve the breadth, depth, and rigor of MBI research.

Mindfulness measures can be classified between those measuring trait or state mindfulness constructs. Trait mindfulness measures assess one’s predisposition to be mindful, which is a stable characteristic or enduring behavioral pattern (Kiken et al, 2015). On the other hand, state mindfulness evaluates the degree to which someone engages in mindfulness at a particular time, which reflects an individual’s experience during a certain time or situation (Medvedev et al., 2017). State mindfulness is fluid and context dependent, such as during an MBI, whereas trait mindfulness captures long-term effects of MBIs (Truong et al., 2020). Medvedev and colleagues (2017) noted that with the increase of MBIs, measuring trait and state mindfulness is imperative to explore which is enhanced through MBIs (Carsley & Heath, 2019; Greco et al., 2011). There are tools that measure state (i.e., MSQ) and trait (i.e., CHIME-A, MAAS-C, MTASA, MSPTA) mindfulness and it is important to consider these tools when implementing MBI for youth.

Given the proliferation of MBIs in research and the benefits found for youth, practitioners and researchers continue to implement MBIs and evaluate outcomes. For researchers to fill the gaps in the literature that exist and attempt to examine the effectiveness of mindfulness, it is imperative to understand what measures are available to evaluate mindfulness. Previous research has identified youth measures and provided descriptions of tools (e.g., Eklund et al., 2017), however, an updated systematic review of mindfulness self-report measures for children and adolescents is necessary given the increased number of measures that have been widely used and developed, as well as explore what measures assess state or trait mindfulness. To enhance the quality of research conducted in this area, it is important to be aware of and select the measurement tools available to adequately capture mindfulness for children and adolescents. The research questions in the current systematic review were as follows:

1. What instruments are available for measuring mindfulness with youth?

2. What mindfulness constructs are evaluated by each measure?

Method

Procedure

Multiple search engines were used to conduct the systematic review. These included PsycTest, PsycINFO, PsycArticles, NCBI, US National Library of Medicine, National Institutes Health, and Google Scholar. Child and adolescent mindfulness measures were identified through keyword searches including the following: “mindfulness scale(s),” “adolescent mindfulness scale(s),” “child mindfulness scale(s),” “mindfulness measures,” “adolescent mindfulness measure(s),” “child mindfulness measure(s),” “mindfulness adolescents,” “mindfulness children,” “mindfulness-based scales,” “mindfulness-based scales adolescents,” “mindfulness-based scales children,” “mindfulness meditation for adolescents,” “mindfulness meditation for children.” The test and measure function through EBSCO host tools and APAPsychTest were used to verify and confirm measures found using the search terms listed above. When an article’s focus was on a measure or an article included a mindfulness measure used in their study, the measures were searched individually by title. Accessing reference lists of relevant and key articles and searching for articles were also employed. The initial search produced 161,334 articles from PsycTest, PsycINFO, and PsycArticles and 17,500 from Google Scholar, for a total of 178,834 articles and 15 measures.

The authors applied inclusion and exclusion criteria to all potential articles and measures found in the initial search. Inclusion criteria required that the measure: (1) included the term mindful or mindfulness in the title of the measure or in the name of one or more constructs; (2) reported to assess one or more constructs of mindfulness; (3) was designed for children or adolescents; (4) published in English; and (5) was self-report. Measures that have been published in peer-reviewed journals and those that were not published in peer-reviewed journals were included. Measures with a range of psychometric data were included. Measures were excluded if they failed to meet the above criteria. In addition, measures that evaluated physiological or biological outcomes, targeted a specific diagnosis (e.g., substance abuse, trauma), created for use in a specific context (e.g., workplace), or evaluated the implementation of specific intervention components were excluded. For example, the Mindfulness Organizing Scale (MOS; Magnano et al., 2017) was excluded because it examined employees’ mindfulness from a workplace perspective and focused on adults. The other excluded measures were: Mindful Eating Questionnaire for Children (MEQ-C; Hart et al., 2018) and the Sexual Mindfulness Measure (SMM; Leavitt et al., 2020) given that their focus was a specific biological function (eating and sexuality), and Relaxation-Mindfulness Scale for Adolescents (EREMIND-A; López-González et al., 2018) which was published in Spanish. A total of 11 measures were included in the study after excluding four measures.

Results

A total of 11 mindfulness measures for youth were identified in the current study. All measures were self-report and ranged from use with kindergarten to high school-age students. Measures frequently included attention and awareness constructs and assessed one’s awareness of internal and external experiences. The following provides detailed information about each of the mindfulness measures and are listed in alphabetical order (Table 1).

Table 1 Mindfulness measures for youth
Full size table

Child and Adolescent Mindfulness Measure (CAMM; Greco et al., 2011)

The CAMM has been validated for youth ages 10–17 years who are presenting with clinical or non-clinical challenges. The CAMM is composed of 10 Likert-style self-report statements. All items are negatively worded (or using a negative descriptor), and reverse scored, with the score indicating one’s overall Mindfulness level. For example, one item reads as, “I stop myself from having feelings that I don’t like.” Response options range from 0 = Never true to 4 = Always true. A higher score on the CAMM represents higher levels of trait mindfulness within an individual. Total scale internal consistency varied for a sample of 319 children and adolescents but is reported to be acceptable for both (α = 0.71 for children, α = 0.80 for adolescents) and factor analysis of the CAMM confirms a one-dimensional factor structure (Kuby et al., 2015). Scores are positively correlated with quality of life, academic competence, and social skills, and negatively correlated with internalizing symptoms and externalizing behavioral problems. In addition to English, the CAMM is available in Spanish (García-Rubio et al., 2019; Viñas et al., 2015), Dutch (de Bruin et al., 2014), Greek (Theofanous et al., 2020), and French (Roux et al., 2019). This measure has been commonly used in schools (Mezo et al., 2020) and is available for public use.

Child and Adolescent Mindfulness Measure-Revised (CAMM-R; Mezo et al., 2020)

The CAMM-R is an adapted version of the CAMM (Greco et al., 2011). This revised version improved accessibility for children by modifying language and creating a visual analog scale (VAS) format, which potentially increases comprehension for children (McGrath et al., 1996, cited in Mezo et al., 2020). The original 10 items from the CAMM were retained, and 7 of the items were revised, improving the readability score. Similar to the original CAMM, items are negatively worded (or using a negative descriptor), and reverse scored. An example item reads as “I get mad for having weird feelings.” Response options range from 0 = Never true to 4 = Always true using a VAS with descriptive categories on both ends to enhance and clarify children’s understanding of the response options. Items are summed for a total one-dimensional mindfulness score, with higher scores representing higher levels of mindfulness. The CAMM-R was validated with 53 African American, low socio-economic status children from kindergarten through fourth grade to measure trait mindfulness (Mezo et al., 2020). Total scale internal consistency for the CAMM-R was found to be α = 0.79. Although factor analysis of the CAMM confirms a one-dimensional factor structure, factor analysis has not been conducted with the CAMM-R. The measure is available in English and can be requested from the authors of the measure.

Comprehensive Inventory of Mindfulness Experiences-Adolescents (CHIME-A; Johnson et al., 2017)

The CHIME-A is a self-report trait mindfulness questionnaire validated with 498 youth ages 12 to 14 years (Johnson et al., 2017) and adapted from the Comprehensive Inventory of Mindfulness Experiences for Adults (CHIME; Bergomi et al., 2013). The CHIME-A is composed of 25 Likert-style self-report statements. Items are negatively worded (written using a negative descriptor), and reverse scored. For example, one item reads, “I don’t like it when I am angry or scared and try to get rid of these emotions.” Response options range from 0 = Never true to 4 = Always true. The CHIME-A contains eight constructs: awareness of internal experiences, awareness of external experiences, acting with awareness, openness to experience, decentering and no reactivity, accepting and nonjudgmental orientation, relativity of thoughts, and insightful understanding. Convergent validity between the CHIME-A and well-being, as measured by the Warwick-Edinburgh Mental Health Wellbeing Scale (WEMWBAS) resulted in item-total correlations ranging from 0.52 to 0.85 and divergent validity between the CHIME-A and negative affect (item correlations ranged from 0.24 to 0.78), depression (r = 0.52–0.79) and anxiety (r = 0.26–0.68) as measured on the Depression Anxiety Stress Scale-Short Form (DASS-21) have been reported to be acceptable (Johnson et al., 2017). Test–retest reliability has been conducted on the CHIME-A and was found to be consistent with other studies of adolescent measures of mindfulness and social-emotional functioning ranging from 0.63 to 0.79. Factor analysis indicated an 8-factor model and good internal consistency was held across all 8 subscales (α = 0.65–0.77). According to the authors, because more than 10 items contained a negative item-total correlation within hierarchical models, this illustrates unacceptable internal consistency (r =  − 0.06 to 0.63 in model 1 and r =  − 0.04 to 0.59 in models 2 and 3) (Johnson et al., 2017), and do not suggest using a total CHIME-A score. The CHIME-A is available in English. This measure has been used in school-based settings for research (e.g., Johnson & Wade, 2021). According to the authors of the measure, the measure is available by request.

Five Facet Mindfulness Questionnaire Adolescent-Short Form (FFMQ-A-SF; Cortazar et al., 2020

The FFMQ-A-SF is a trait mindfulness measure validated for ages 10–18 years. It is a shortened version of the FFMQ-A and was adapted from the adult short-form FFMQ (Tran et al., 2013). The FFMQ-A-SF contains 25-items that are positively (written using a positive descriptor and without a negated word) and negatively worded (written using a negative descriptor). Example items include “I can easily put my beliefs, opinions, and expectations into words” (positively worded) and “I don’t pay attention to what I’m doing because I’m daydreaming, worrying, or otherwise distracted” (negatively worded). Response format follows a Likert-style from 1 (Never or Very Rarely True) to 5 (Very Often or Always True). This measure assesses five constructs including acting with awareness, observe, describe, nonjudging of inner experience, and nonreactivity to inner experience. The total scale and subscales demonstrated evidence of discriminant (perspective taking, r =  − 0.14 to 0.28; prosocial behavior, r =  − 11 to 0.11; prosocial behavior, r =  − 0.07 to 0.18), convergent (self-compassion, r = 0.25 to 0.68) validity. The FFMQ total score also demonstrated incremental predictive validity for life satisfaction, perceived stress, positive affect, negative affect, and rumination, using a sample size of 599 high school students (Abujaradeh et al., 2020). The FFMQ-A-SF demonstrated adequate internal consistency (α = 0.82 to 0.85) across multiple assessment times with subscales ranging from α = 0.61 to 0.88 and strong correlations between the FFMQ-A-SF and FFMQ-A (α = 0.93 to 0.96) subscales. Confirmatory factor analysis conducted by the authors of the measure indicated support for the five-factor structure (Cortazar et al., 2020), whereas a separate confirmatory factor analysis of the measure suggested a four-factor structure (removal of Observe construct and one item from the Describe construct) (Abujaradeh et al., 2020). The FFMQ-A -SF is available in English and can be requested from the developers.

Mindful Attention Awareness Scale for Adolescents (MAAS-A; Brown et al., 2011)

The MAAS-A measures trait mindfulness and is validated for use with youth ages 14–18 years who are presenting with clinical or non-clinical challenges. This is an adaptation of the Mindful Attention Awareness Scale (MAAS) for adults. The MAAS-A is composed of 14 Likert-style self-report items and are negatively worded (written using a negative descriptor) such as “I tend not to notice feelings of physical tension or discomfort until they really grab my attention.” Responses range from 1 = Almost always to 6 = Almost never. It contains the same items as the MAAS, except for one item (i.e., “I drive places on ‘automatic pilot’ and then wonder why I went there”) to improve appropriateness for the target age group. High scores on the MAAS-A suggest higher levels of mindfulness and low scores suggest lower levels of mindfulness. The MAAS-A total scale demonstrates good internal reliability (study 1, α = 0.82 to 0.84; study 2, α = 0.86) (Brown et al., 2011) with a sample of 595 adolescent youth. Factor analysis conducted by the measure’s author indicated a one-dimensional structure. (Brown et al., 2011). MAAS-A scores have been found to be positively correlated with self-regulation, quality of life, and wellness and negatively correlated with stress, rumination, and catastrophizing. The measure is available in English and Dutch (de Bruin et al., 2011). The MAAS-A have been used in school settings (Patton et al., 2019) and is available for public use.

Mindful Attention Awareness Scale for Children (MAAS-C; Benn, Unpublished Data)

The MAAS-C examines trait mindfulness for youth ages 9 to 13 years and is an adaptation of the MAAS. The MAAS-C is comprised of 15 items. Items are negatively worded (written using a negative descriptor), and reverse scored. An example of a question on the measure is “I snack without being aware that I am eating.” Responses range from 1 = Almost never to 6 = Almost always and higher scores represent higher levels of mindfulness. The MAAS-C total scale shows good internal reliability (α = 0.84) with a sample of 386 children in grade 4–7 (Lawlor et al., 2014) and exploratory factor analysis indicated a one-dimensional structure and high internal consistency (α = 0.84). Scores on the MAAS-C have been positively correlated with optimism, positive affect, and academic achievement and negatively correlated with depression, anxiety, and rumination. The measure is available in English. It can be accessed in Lawlor and colleagues’ (2014) article.

Mindful Student Questionnaire (MSQ; Renshaw, 2017)

The MSQ is a state mindfulness measure validated for use with 6th–8th grade students and specifically to be used in school settings. The MSQ contains 15 items that are positively worded (written using a positive descriptor and without a negated word) and are phrased to directly represent the constructs of interest. Ranges of responses are 1 = Almost never to 4 = Almost always. Items of the MSQ focus on three constructs: mindfulness attention, mindfulness acceptance, and approach and persistence. The MSQ was validated using 278 adolescents and demonstrated structural and convergent validity between MSQ subscales and subscales on the Student Subjective Wellbeing Questionnaire (SSWQ; Renshaw et al., 2015) and the SSRA which was adapted from the California Healthy Kids Survey (WestEd, 2014) (ranged from α = 0.19 to 0.55). Higher correlations were found between the MSQ subscales and expected subscales such as mindful acceptance and mindful attention and lower between MSQ subscales and school connectedness and academic achievement. Adequate internal consistency for the three subscales (α =  > 0.70), and factor analysis confirming a three-factor model (Renshaw, 2017) have also been found. The MSQ is available in English and has been used in educational settings for research (e.g., Kielty et al., 2017). For access to the MSQ, contact the measure developer.

Mindful Thinking and Action Scale for Adolescents (MTASA; West et al., 2007)

The MTASA measures trait mindfulness for adolescents ages 13 to 17 years. This scale was designed to assess mindful thinking and action in children and adolescents. The MTASA is a 32-item self-report Likert style measure with items both positively (written using a positive descriptor and without a negated word) and negatively worded (written using a negative descriptor). Response options range from 1 = Never to 5 = Almost always. The four constructs include active attention, awareness and observation, healthy self-regulation (HSR), and accepting experience (West, 2008). Exploratory factor analysis supported the four-factor model and has good overall total scale internal consistency (α = 0.85) with a sample of 600 non-clinical youth (West, 2008). The HSR construct of the MTASA has shown positive correlations with the CAMM and MAAS-A (de Bruin et al., 2014). MTASA is available in English and available upon request from the developers.

Mindfulness Inventory for Children and Adolescents (MICA; Briere, 2011)

The MICA is intended for youth ages 8 to 18 years to measure trait mindfulness. The MICA items and constructs were created by a subject-matter expert who integrated Buddhist concepts of mindfulness and a psychological understanding of child cognitive development (Briere, 2011). The MICA is comprised of 25-items and are worded positively (written using a positive descriptor and without a negated word) and negatively (written using a negative descriptor). Responses on the measure range from 1 = Disagree a lot to 5 = Agree a lot. The MICA measures five constructs of mindfulness including: self-acceptance, present-centered awareness, equanimity, metacognitive awareness, and acceptance of internal experience (Goodman et al., 2017). The MICA has not yet been psychometrically evaluated or validated therefore reliability, validity, and factor analysis data cannot be reported. This measure has only been developed in the English language (Goodman et al., 2017) and is available from the author of the MICA.

Mindfulness Scale for Pre-Teens, Teens, and Adults (MSPTA; Droutman, 2015)

The MSPTA has been created to measure trait mindfulness with youth ages 9–19 years and with young adults ages 17–25 years (Droutman, 2015). The MSPTA is comprised of 19–items that are both positively (written using a positive descriptor and without a negated word) and negatively (written using a negative descriptor) worded. Response options range from 1 = Never true to 5 = Always true. The four mindfulness constructs evaluated on the measure include: attention and awareness, being non-reactive, being non-judgmental, and being non-self-critical. MSPTA was validated with children, adolescents, and adults, and demonstrated good overall total scale internal reliability (α = 0.84) and acceptable internal reliability across constructs (α = 0.71 to 0.77). Factor analysis confirmed the four-factor model of the measure (Goodman et al., 2017). The MSPTA is the only scale available that is validated on pre-adolescents to adults (Droutman, 2015). MSPTA is available in English and upon request from the developers.

Self-Compassion Scale -Youth Version (SCS-Youth; Neff et al., 2021)

The SCS-Y measures self-compassion (a component of mindfulness) and can be used with adolescents ages 11–15. The SCS-Y was adapted from the SCS. This measure contains 17 items that are written positively (written using a positive descriptor and without a negated word) and negatively (written using a negative descriptor) worded items. An example of a positively worded item is “I try to be kind and supportive to myself when I’m having a hard time” and an example of a negatively worded item is “I get mad at myself for not being better at some things.” Response options range from 1 = Almost never to 5 = Almost always. The six constructs on the SCS-Y are self-kindness, self-judgement, common humanity, isolation, mindfulness, and overidentification. The option of a total score can also be calculated by taking the total mean of the six constructs means. The SCS-Y demonstrated good internal consistency (α = 0.82 and 0.85) in two different studies (both studies within Neff et al., 2021) and factor analysis confirmed the use of six constructs and one general total construct for the measure using a sample of 279 youth ranging between the ages of 11–15 years old. Test–retest reliability ( r = 0.51 to 0.83) results suggested that the SCS-Y is a stable measure of self-compassion over time. Results have also supported the construct validity of the measure (Neff et al., 2021). The measure is available in English and available for public use.

Discussion

The implementation and research of MBIs have been increasing in schools, given the beneficial outcomes found for youth (e.g., Bender et al., 2018). For researchers to fill the gaps in the literature that exist and attempt to continue understanding the effectiveness of MBIs, identifying measures available to examine mindfulness is necessary (Van Dam et al., 2018). An important way to improve the understanding of mindfulness processes is to examine the measures that capture mindfulness constructs (Christopher et al., 2015). The aim of this paper was to identify and review current measures of mindfulness for children and adolescents. The intent was to provide an overview of the current state and availability of measures for practitioners and researchers allied with the field of mindfulness to have better access to and understanding of mindfulness measures to support their work with youth.

A total of 11 child and adolescent measures were identified and examined. Three (CAMM, MASS-A, FFMQ) of the 11 measures were available in languages other than English including Dutch, Italian, Spanish, French, and Greek. Five (CAMM, MAAS-A, MAAS-C, FFMQ and SCS-Y) of the 11 measures are publicly available online with the remaining accessible through their respective authors.

Of the measures found, four assessed a unidimensional construct of mindfulness, whereas six measures evaluated multiple facets of mindfulness, as evidenced by multiple constructs being included on the measure. One measure included the option of evaluating mindfulness multidimensionally on six constructs as well as provided instructions on how to combine them to yield a total unidimensional mindfulness construct. Almost all measures (n = 9) had either exploratory or confirmatory factor analyses conducted to confirm the factor structure. This finding is not surprising, as it is reflective of research indicating that mindfulness is not a unidimensional concept (Goodman et al., 2017; Van Dam et al., 2018) and rather more adequately captured using constructs such as awareness, nonjudgmental acceptance, and present-moment attention (Blanke & Brose, 2017), a model that is aligned with Kabat-Zinn's definition of mindfulness in the USA. Measures often included attention and awareness constructs and assessed one’s awareness of internal and external experiences. All measures reviewed were self-report measures ranging from 7 to 65 items per scale. The youngest self-report measure of mindfulness could be used with children aged 9 years (MSPTA; Droutman, 2015), with some indication that measurements may be appropriate for participants as young as 7 years old (MAAS-C; Lawlor et al., 2014) and kindergarten students (CAMM-R; Mezo et al., 2020).

The trend of adapting adult measures to youth populations was found, but less frequently than expected. Five (MAAS-A, MAAS-C, CHIME-A, FFMQ, and SCS) of the 11 measures were adapted from adult measures with many of the items remaining identical. As a focus on mindfulness in schools has increased (Zenner et al., 2014), measures have been adapted with the intent to measure mindfulness specifically in a school setting (MSQ and MTASA) to address the realities adolescents face in schools. Furthermore, measures have been adapted to ensure developmentally appropriate language such as the CAMM-R (Mezo et al., 2020). A major adaptation between the CAMM and CAMM-R was improving youth comprehension of the measure by modifying language on the items and creating a visual analog scale (VAS) for youth to respond to. Along these lines, Cortazar and colleagues (2020) examined the FFMQ-A and found that younger participants may have a poorer understanding of the intended meaning of items that were negatively worded (versus positively worded) on the measure. They found that they tended to respond higher to items that were positively worded. Considering positive and negative wording of items (Van Dam et al., 2012) as well as ensuring readability and comprehension for youth completing the measures is an important consideration when selecting measures to use with youth in schools. Item content from measures, if not reported by authors, could be subjected to readability analyses such as the Readability Analyzer (https://datayze.com/readability-analyzer.php) to provide an estimate of how youth at varying grade levels may comprehend content and provide guidance on appropriate selection of measures.

In our review, we found 11 mindfulness measures for children and adolescents. This is about half the number of mindfulness measures that have been found for adults (e.g., Bender et al., in progress). We believe this reflects the historical roots of mindfulness and original development of mindfulness-based stress reduction (MBSR; Kabat-Zinn, 1990). MBSR and other mindfulness interventions (e.g., mindfulness-based cognitive therapy) were originally created for adults, therefore it makes sense that there are more measures of self-reported mindfulness available. Similar to the measurement of other constructs in psychology (e.g., depression, anxiety), measures are often developed for adults and then later adapted for youth. Several of the self-report measures identified in the current study for youth have been developed in the last few years (2017–2020), mirroring the trend toward increased mindfulness interventions aimed at adolescents (Klingbeil et al., 2017a), especially in schools, and it is likely that measures for children and adolescents will continue in their growth. Researchers and practitioners should be aware of this trend given that some of the adult measures have not been adapted with child and adolescent metacognitive or developmental level in mind (Goodman et al., 2017). For instance, in a study using the FFMQ (Van Dam et al., 2012), adult meditators and nonmeditators were influenced by negatively worded items compared to positively worded items on the measure. If this is the case for adults, it could also be the case for youth.

In terms of state vs. trait mindfulness, the majority of measures in our review examined trait mindfulness (CAMM, CAMM-R, CHIME-A, MAAS-A, MAAS-C, MICA, MSPTA, MTASA, FFMQ), whereas only one measure was a state mindfulness measure (MSQ) and one focused on self-compassion (SCS-Y) which has been proposed as part of the mindfulness construct (Rosenzweig, 2013). It has been noted that increases in state mindfulness (the degree to which someone engages in mindfulness at a particular time; Medvedev et al., 2017) may lead to greater levels of trait mindfulness, which is considered stable, a dispositional quality, and linked to positive changes in health (Kiken et al., 2015). While measurement of trait mindfulness is important to understand the possible long-term effects of mindfulness, observing changes at the trait level may be beyond the scope and intent of interventions in schools. In other words, a state mindfulness measure examines the degree to which one engages in mindfulness at a particular time and/or is the capacity to cultivate a particular state of mind during meditative practice (Goodman et al., 2017), which may be more appropriate to assess during and after MBIs since it is fluid and context dependent, yet there is only one state available for use with youth. Further research is needed to differentiate between state versus trait mindfulness and which type of measure to use for youth, especially within the context of schools. This will help to improve the quality of the measures, identifying potential constructs that contribute to the mindfulness process, and how it impacts outcomes.

Although MBIs, programs, and curricula have been increasing in implementation, there are few measures available to measure mindfulness constructs for children and adolescents. It has been documented that there has been significantly more research conducted on MBI evaluation and much less assessing the construct of mindfulness, particularly for youth (Eklund et al., 2017). Some mindfulness programs are used with very young children, such as preschool and kindergarten age students (e.g., Calm Classroom, Kindness Curriculum), yet only one measure was found that could be used to work with children as young as kindergarten (CAMM-R, Mezo et al., 2020). It raises the question of how mindfulness processes can be measured for this age group, while taking children’s development into consideration. Although mindfulness is often assessed for older children, adolescents, and adults using self-report, Eklund and colleagues (2017) posed the question of whether a self-report mindfulness questionnaire for children is developmentally appropriate. This is an important point raised, given that many other self-report measures of behavior and emotions (e.g., BASC, CBCL, etc.) are recommended to be used for children 7 and older. Along these lines, it is important to consider how items are phrased and how measures are administered for children this young to capture mindfulness for this age and developmental group.

Limitations and Future Directions

It is important to acknowledge the limitations in the current study. The researchers included mindfulness measures that were available in the English language. If measures were included in English and another language, it was included in our study, however if it was only available in another language, they were excluded in the review. While we noted if measures were available in languages other than English, and included studies that were conducted outside the USA, if a version of a measure was not available in English, we did not include it in our review. This may overly emphasize a US-centric view of mindfulness (how it is conceptualized and measured) which is limiting given that mindfulness originated in different languages in Eastern countries. For example, while mindfulness in the USA is often conceptualized as nonjudgmental, person-centered awareness, Feng and colleagues (2018) found that “Buddhist mindfulness contains elements of attentional flexibility, skillfulness, purposefulness, wisdom, and ethics. Buddhist mindfulness not only involves awareness of the present but also the past and future. It not only focuses on self but also on others” (p. 441). Research has suggested that the adult mindfulness measures Kentucky Inventory of Mindfulness Skills (KIMS) and Five Factor Mindfulness Questionnaire (FFMQ) were more congruent with Buddhist principles of mindfulness compared to the Mindfulness Attention and Awareness Scale (MAAS) and Freiburg Mindfulness Inventory-30 (FMI-30) (Feng et al., 2018). Future research evaluating youth measures in this manner would be important.

In examining the various constructs of the measures in this systematic review, we found that more than half of the measures captured mindfulness multidimensionally, rather than unidimensionally, which is consistent with research on mindfulness theory (e.g., Goodman et al., 2017; Van Dam et al., 2018). Constructs such as awareness, nonjudgmental acceptance, and present-moment attention (Blanke & Brose, 2017) are aligned with Kabat-Zinn’s definition of mindfulness, which is widely used and cited in the USA. While Kabat-Zinn’s work was and continues to be seminal to US mindfulness work, it is important that the history, origins, theoretical and practical underpinnings of mindfulness are not lost. While transnational work is adapted to meet the culture and context of various populations across the world, those conducting mindfulness work in the USA would benefit from continued learning, reflecting, and acknowledging the roots of the tradition and practice from Eastern cultures. For a more in-depth discussion of historical practices and comparison of Eastern and Western conceptualizations of mindfulness as well as how these practices are reflected in self-reported measures for adults, see Feng et al. (2018).

Another limitation to note is that additional measures that are mindfulness adjacent (such as measuring aspects of mindfulness) may not have been captured in our search due to the eligibility criteria used. One of the study’s criteria was that the measure had to include the term “mindful” or “mindfulness” in the title of the measure or for one or more constructs measured. However, some measures such as the Avoidance and Fusion Questionnaire for Youth (AFQ-Y; Greco et al., 2008) were developed based on mindfulness theory as adapted by acceptance and commitment therapy (ACT), but the instrument does not use “mindful” in the scale or construct names. Yet a measure such as this might be used by school psychologists to evaluate mindfulness adjacent constructs with youth.

Given that the purpose of the study was to identify and describe current mindfulness measures available to researchers and practitioners, information pertaining to the citation count or in-depth psychometrics was not included. However, further analysis and independent evaluations of psychometrics, such as content validity for youth measures is an essential future direction to understand effective measurement of targeted constructs. Some measures reviewed begun preliminary work in examining correlations between mindfulness constructs with other youth measures. For example, the HSR construct on the MTASA was found to be correlated with the CAMM and MAAS-A (de Bruin et al., 2014). However, given that our study found that varying definitions of mindfulness continue to be used and result in measures that assess different constructs of mindfulness (e.g., varying constructs on measures, unidimensional vs. multidimensional mindfulness), continued work investigating the intercorrelations between measures and what constructs on measures demonstrate convergent and divergent validity is necessary. This has also been identified as an area of future research by others supporting the need for psychometric work in this area (Mezo et al., 2020).

Furthermore, given the increase of MBI implementation in schools settings, it would also be important to better understand what measures are most appropriate to capture mindfulness in schools. The MSQ was specifically designed to examine students’ experience of mindfulness in educational contexts, with language use and examples provided on items to be relevant for this context. In addition, current measures should continue to be validated and psychometric properties of measures carefully examined when selecting measures to use with target populations (Krägeloh et al., 2018). As reported by previous researchers, mindfulness constructs assessed via self-report measure are rarely used when school based MBIs are implemented. When measures assessing mindfulness constructs are used, they are often implemented immediately after the intervention. This is promising, as it suggests that the measures that have been used in intervention studies (e.g., CAMM, MAAS-A) are sensitive to changes for youth but they are rarely assessed long-term therefore little is known about the sustained benefits of mindfulness (Eklund et al., 2017).

Along the same lines, considering the method of how mindfulness is captured for youth is an important future direction. It is common to assess mindfulness via self-report, given that it is an internal, mental process, which is consistent with the adult mindfulness measure literature (e.g., Baer, 2011). However, researchers have recommended considering additional ways to measure mindfulness, such as observation of particular behaviors related to mindfulness (self-regulation) or asking people open-ended questions or vignettes to describe their thoughts and feelings (i.e., Measure of Awareness and Coping in Autobiographical Memory [MACAM]; Moore et al., 1996). Further, Goodman et al. (2017) highlighted the benefits of adequately selecting state versus trait measures when working with youth. Depending on the setting, state mindfulness measures might be used more frequently to measure the reduction of symptoms following MBIs (Carsley & Heath, 2019) whereas trait mindfulness measures may be better suited to track dispositional mindfulness or long-term effects of MBIs for youth. Although few state measures of mindfulness currently exist for youth, there are some available for adults, such as State-MAAS (Brown & Ryan, 2003), Toronto Mindfulness Scale (TMS; Lau et al., 2006) and the State Mindfulness Scale (SMS; Tanay & Bernstein, 2013). Considering the adaptation of these for youth in schools, similar to how other mindfulness measures for youth have been constructed, may be useful in achieving this goal. Thus, future investigation of alternate ways to capture mindfulness and understand how the use of multiple methods and/or raters could contribute to a more accurate assessment of youth’s mindfulness experience would be beneficial.