The Effectiveness and Acceptability of Formal Versus Informal Mindful Self-Compassion for Adolescents

The Coping Index (CI; Stallman, 2017) is a 20-item self-report measure of healthy (10 items) and unhealthy (10 items) coping behaviors based on the Health Theory of Coping (Stallman, 2020). Respondents rate how often they use each behavior to feel better when they are feeling stressed or distressed using a 4-point Likert scale ranging from I do not do this at all (0) to I do this most of the time (3). The item, 'Have thoughts about suicide', will be omitted for the purposes of this study; an adapted 19-item version of the CI will therefore be used. A coping index score will be computed, which is the healthy subscale mean minus the unhealthy subscale mean (possible range: 3 to -3). A higher score reflects a better outcome.

The Coping Index (CI; Stallman, 2017) is a 20-item self-report measure of healthy (10 items) and unhealthy (10 items) coping behaviors based on the Health Theory of Coping (Stallman, 2020). Respondents rate how often they use each behavior to feel better when they are feeling stressed or distressed using a 4-point Likert scale ranging from I do not do this at all (0) to I do this most of the time (3). The item, 'Have thoughts about suicide', will be omitted for the purposes of this study; an adapted 19-item version of the CI will therefore be used. A coping index score will be computed, which is the healthy subscale mean minus the unhealthy subscale mean (possible range: 3 to -3). A higher score reflects a better outcome.

The 18-item Five Facets of Mindfulness Questionnaire (FFMQ-18; Medvedev et al., 2018) is a self-report measure of dispositional (i.e., trait) mindfulness. It consists of five subscales, each reflecting one facet of mindfulness (acting with awareness, nonjudgmental acceptance, nonreactivity, observing, and describing). Items are rated on a 5-point Likert scale ranging from Never or very rarely true (1) to Very often or always true (5). The FFMQ-18 is the most reliable and valid short form of the full-scale (39-item) FFMQ (Medvedev et al., 2018). A global mean will be computed (possible range: 1 to 5) whereby a higher score reflects a better outcome.

The Self-Compassion Scale - Short Form (SCS-SF; Raes et al., 2011) is a 12-item self-report measure of self-compassion. Respondents are asked to indicate how often they behave in the stated manner using a 5-point Likert scale ranging from Almost never (1) to Almost always (5). The SCS-SF has a near-perfect correlation with the full-scale SCS and is a reliable alternative when assessing overall self-compassion (Raes et al., 2011). A global mean will be computed (possible range: 1 to 5) whereby a higher score reflects a better outcome.

The Perceived Stress Scale (PSS; Cohen et al., 1983) is a 10-item self-report measure of perceived stress. Respondents are asked to rate each item on a 5-point Likert scale (0 = Never to 4 = Very often) based on how often they feel or think a certain away. A sum score will be computed (possible range: 0 to 40) whereby a higher score reflects a worse outcome.

The Generalized Anxiety Disorder scale (GAD-7; Spitzer et al., 2006) is a widely used 7-item self-report measure of anxiety. Respondents are prompted to indicate using a 4-point Likert scale ranging from Not at all (0) to Nearly every day (3) how often they experienced each anxiety symptom listed over the past two weeks. A sum score will be computed (possible range: 0 to 21) whereby a higher score reflects a worse outcome.

The Patient Health Questionnaire - Modified for Adolescents (PHQ-A; Johnson, 2002) is a 9-item self-report measure of depression for adolescents, adapted from the widely-used adult version. Respondents are asked to indicate how often they experienced each depressive symptom listed over the past two weeks using a 4-point Likert scale ranging from Not at all (0) to Nearly every day (3). The item, 'Thoughts that you would be better off dead, or of hurting yourself in some way?', will be omitted for the purposes of this study; an adapted 8-item version of the PHQ-A will therefore be used. A sum score will be computed (possible range: 0 to 24) whereby a higher score reflects a worse outcome.

The Theoretical Framework of Acceptability questionnaire (TFA; Sekhon et al., 2022) is an 8-item self-report measure of intervention acceptability that will only be administered 1-week post-intervention to those in the MSC-F and MSC-I conditions. The TFA questionnaire is adaptable and can be used to evaluate a variety of healthcare interventions (including mental healthcare). It consists of seven items, each pertaining to one of the components listed above, as well as an eighth item that assesses general acceptability. Items are rated on 5-point Likert scales (with varying labels depending on the item). A global mean will be computed (possible range: 1 to 5) whereby a higher score reflects a better outcome.

In addition, 5 researcher-developed, follow-up open-ended questions will be asked at the end of the TFA to obtain more detailed information regarding intervention acceptability (e.g., What did you like the most about the program?).

The Self-Oriented Perfectionism subscale of the Multidimensional Perfectionism Scale (MPS; Hewitt & Flett, 1991, 2004) is a 15-item measure of perfectionism. Respondents are asked to indicate their agreement with each item using a 7-point Likert scale ranging from Strongly disagree (1) to Strongly agree (7). A sum score will be computed (possible range: 15 to 105) whereby a higher score reflects a worse outcome.

The Self-Critical Rumination Scale (SCRS; Smart et al., 2016) is a 10-item self-report measure of self-critical rumination. Respondents are asked to indicate how well each item describes them using a 4-point Likert scale ranging from Not at all (1) to Very well (4). A global mean will be computed (possible range: 1 to 4) whereby a higher score reflects a worse outcome.

The Difficulties in Emotion Regulation Scale - Short Form (DERS-SF; Kaufman et al., 2015) is an 18-item measure of emotion dysregulation. Respondents are asked to indicate how often each statement applies to them using a 5-point Likert scale ranging from Almost never (1) to Almost always (5). A sum score will be computed (possible range: 18 to 90) whereby a higher score reflects a worse outcome.

The Utrecht Work Engagement Scale for Students (UWES-9S; Schaufeli et al., 2002) is a 9-item self-report measure of academic engagement. Items are rated on a 7-point Likert scale ranging from Never (1) to Always/every day (7) based on the frequency with which the respondent experiences each statement. A global mean will be computed (possible range: 1 to 7) whereby a higher score reflects a better outcome.

A brief researcher-developed Home Practice Survey will be used to assess, on a weekly basis, the amount of independent mindfulness practice participants complete throughout the 4-week intervention period. This measure consists of 2-4 items (depending on participants' responses) which ask about participants' frequency of practice and specific practices used over the last week.