Background: There is a high prevalence of children and young people (CYP) experiencing mental health (MH) problems. Owing to accessibility, affordability, and scalability, an increasing number of digital health interventions (DHIs) have been developed and incorporated into MH treatment. Studies have shown the potential of DHIs to improve MH outcomes. However, the modes of delivery used to engage CYP in digital MH interventions may differ, with implications for the extent to which findings pertain to the level of engagement with the DHI. Knowledge of the various modalities could aid in the development of interventions that are acceptable and feasible.Objective: This review aimed to (1) identify modes of delivery used in CYP digital MH interventions, (2) explore influencing factors to usage and implementation, and (3) investigate ways in which the interventions have been evaluated and whether CYP engage in DHIs.Methods: A literature search was performed in the Cochrane Library, Excerpta Medica dataBASE (EMBASE), Medical Literature Analysis and Retrieval System Online (MEDLINE), and PsycINFO databases using 3 key concepts “child and adolescent mental health,” “digital intervention,” and “engagement.” Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed using rigorous inclusion criteria and screening by at least two reviewers. The selected articles were assessed for quality using the mixed methods appraisal tool, and data were extracted to address the review aims. Data aggregation and synthesis were conducted and presented as descriptive numerical summaries and a narrative synthesis, respectively.Results: This study identified 6 modes of delivery from 83 articles and 71 interventions for engaging CYP: (1) websites, (2) games and computer-assisted programs, (3) apps, (4) robots and digital devices, (5) virtual reality, and (6) mobile text messaging. Overall, 2 themes emerged highlighting intervention-specific and person-specific barriers and facilitators to CYP’s engagement. These themes encompassed factors such as suitability, usability, and acceptability of the DHIs and motivation, capability, and opportunity for the CYP using DHIs. The literature highlighted that CYP prefer DHIs with features such as videos, limited text, ability to personalize, ability to connect with others, and options to receive text message reminders. The findings of this review suggest a high average retention rate of 79% in studies involving various DHIs.Conclusions: The development of DHIs is increasing and may be of interest to CYP, particularly in the area of MH treatment. With continuous technological advancements, it is important to know which modalities may increase engagement and help CYP who are facing MH problems. This review identified the existing modalities and highlighted the influencing factors from the perspective of CYP. This knowledge provides information that can be used to design and evaluate new interventions and offers important theoretical insights into how and why CYP engage in DHIs.

Acceptance and commitment therapy (ACT), a newer type of behavior therapy that targets psychological flexibility, may have particular utility in the context of muscle disorders. However, there has been no formal investigation of psychological flexibility in this population. This longitudinal observational study investigated whether psychological flexibility is cross-sectionally related to, and prospectively influential on, life satisfaction and mood in muscle disorders. Data were collected via online questionnaire batteries, completed at baseline and then repeated 4 months later. Cross-sectional and prospective regression analyses examined relationships between validated measures of disability level, psychological flexibility (experiential avoidance, cognitive fusion, and valued living) and illness perceptions (a psychological variable with known influence in muscle disorders), and outcomes (life satisfaction, anxiety, and depression). A sample of 137 people with a range of muscle disorders participated. In cross-sectional analyses, psychological flexibility explained significant unique variance in addition to illness perceptions (ΔR2 = 0.17-0.34, p < .001). In prospective analyses, psychological flexibility alone was predictive of change in life satisfaction (ΔR2 = 0.04, p = .01) and anxiety (ΔR2 = 0.03, p = .04) over 4 months. No independent variables were predictive of change in depression over 4 months, and disability level had no significant influence on outcomes. Psychological flexibility influences important outcomes in muscle disorders. Experimental studies are required to establish if increased psychological flexibility leads to improved outcomes. (PsycINFO Database Record