Table 1.

Main TEME^a framework findings across studies^b.

TEME framework	Main findings
Target audience	Studies mainly consisted of nonclinical (n=23) midadolescent youth (mean age 16.04, SD 3.63 years). The majority of samples included male and female participants. Sample sizes varied across studies, ranging from an average of 25.25 (qualitative, SD 16.15) to 237.12 (quantitative, SD 387.88) youth. Additionally, study designs primarily consisted of randomized controlled trials (n=12) or observational studies (n=5).
Levels of engagement	Across studies, on average, the prescribed video game or app engagement included 6 weeks of total use (SD 4.89), including an average of 12.27 sessions (SD 13.74). Prescribed gameplay averaged 40.28 minutes (SD 21.57). Most studies used computers or laptops to host the games.
Mechanisms of action	We identified 28 different video and app-based games across the included studies. Game types mainly consisted of serious games (n=26), with adventure (n=11) and challenge (n=7) games appearing most often as subcategories and associated with positive ERc outcomes. Across game descriptions, primary mechanisms of action included ER skills, including psychoeducation, resilience-building, coping strategies, cognitive reframing, decision-making, problem-solving, relaxation, and self-monitoring. The majority of games were designed to be played individually.
Effectiveness	Overall, studies primarily reported positive (n=16) and mixed (n=15) findings following video and app-based game use, with 2 studies reporting null results. ER outcome domains included change in overall ER skills (n=16; eg, reported increases in coping skills and self-expression), mood modification (n=12; eg, reported increases and decreases in positive and negative affect), mental health symptom management (n=11; eg, mixed anxiety outcomes and reported improvement in prosocial behavior), and emotion identification (n=4; eg, reported improvement in emotional awareness). However, key caveats include many of the studies reporting limitations such as a small sample size and being underpowered (n=19), participant homogeneity (n=5), and needing longer-term follow-up (n=9).

^aTEME: target audience, engagement, mechanisms of action, and effectiveness.

^bMore details can be found in Multimedia Appendix 3.

^cER: emotion regulation.