Mindfulness-Based Intervention for Mild Traumatic Brain Injury

Descriptive variable. Ease of recruitment will be defined as having at least 60% approached and eligible participants agreeing to participate. A higher score means easier recruitment.

The Credibility and Expectancy Questionnaire is a 6-item The credibility score is derived from the items 1-3 and the expectancy scores is derived from the items 4-6. A higher score means better credibility. The treatment will be considered as credible if 80% of the participants rated the treatment as credible.

Descriptive variable. Adequate retention will be defined as having 70% of participants completing at least 60% of the 4-week intervention and the outcome measurement post-treatment. A higher score means better retention.

Calculated based on the time spent on the app. A higher score means better adherence.

The Pediatric Quality of Life Inventory™ version 4.0 is a reliable and valid measure of quality of life in healthy children and adolescents and those with acute and/or chronic health conditions.The inventory covers four domains: physical, emotional, social, and school. It is a 23-item, 5-point Likert scale producing a total score (range=0-92) and 4 domain scores (physical, emotional, social, and school). Higher scores indicate better outcomes.

The Health and Behaviour Inventory is validated symptom scale. It is a 20-item self-report questionnaire, 4-point Likert scale (total range 0-60) yielding scores for cognitive and somatic symptom scales. A higher score indicate worse outcome.

The Post-Concussion Symptom Inventory (PCSI) is a validated, reliable, comprehensive, self-administered instrument for children and adolescents. For the purpose of this study, the emotional and sleep domain of the PCSI adolescent scale version (20-item, 7-point Likert scale) will be used. A higher score indicate worse outcome.

The Self-Efficacy Questionnaire for Children is a valid and reliable assessment, Cronbach's α=0.88. It is a 24-item, 5-point Likert scale questionnaire producing a total score (0-120), and emotional, social, and academic sub-scores. A higher score indicate better outcome.

The NIH Toolbox Cognitive Battery, a validated and reliable computerized battery designed to measure fluid cognitive functioning (executive function, attention, episodic memory, language, processing speed, and working memory). Raw performance is transformed to age-corrected standard scores, for which the normative mean in 100 and the standard deviation is 15. Other types of scores computed by the battery include fully corrected t-scores (mean of 50 and standard deviation of 10, comparing the score of the participant to those of the normative sample while adjusting for key demographic variables: age, gender, race/ethnicity, educational attainment), uncorrected standard scores (normative mean of 100 and standard deviation of 100), percentiles. Higher scores indicate better outcomes.

The Connor-Davidson Resilience Scale-10 is a validated questionnaire in an adolescent concussed population. It is a 10-item, 5-point Likert scale assessing the individual's own perception of hardiness or perceived stress (total score range=0-40). A higher score indicates better outcome.

The GAD-7 is a validated, reliable, and sensitive to treatment-related changes tool that assesses anxiety symptoms in youth. It is a 7-item, 3-point Likert scale questionnaire providing a sum score (0-21) of the level of general anxiety disorder. A higher score indicate worse outcome.

This is a 10-item, 4-point Likert scale questionnaire assessing the level of depression symptoms in the past week. A higher score indicate worse outcome. Total scores can range from 0 to 30. A higher score indicate worse outcome.

The Child and Adolescent Mindfulness Measure is a validated, 10-item, 5-point Likert scale questionnaire. A higher score indicate better outcome.

A subset of 60 participants will undergo a magnetic resonance imaging scan (MRI), which includes a resting-state functional MRI to assess function connectivity. To measure intra- and interconnectivity between regions of interest (default-mode network) and regions across the brain, will be measured. To calculate functional connectivity per participant, the mean blood-oxygen-level dependent (BOLD) signal time series will be extracted for each individual seed-region. Then, the correlation coefficients between the time series of each seed region will be grouped into functional connectivity maps. The functional connectivity maps will be converted into z-scores for normality and used for the statistical analysis. Whole-brain and region of interest functionally connectivity analysis will be conducted.