The goal of this observational, community-based study is to evaluate the effectiveness of a complex intervention designed to reduce problematic video game use and the risk of video game addiction in adolescents, while promoting active, shared leisure activities and personal and emotional development.

The study involves students in the first year of secondary education (approximately 12-13 years old) from multiple schools in Pontevedra (Galicia, Spain), as well as adults from their close environment, including family members, teachers, health professionals, and community representatives. Schools are assigned either to an intervention group or to a control group with similar sociodemographic characteristics.

The study is based on a systems and community perspective, assuming that adolescents' video game use is influenced by individual factors (such as impulsivity and emotional regulation), as well as by family, school, and community contexts and the availability of appealing leisure alternatives. For this reason, the intervention consists of three coordinated components that are implemented over time in the intervention schools.

The main questions the study aims to answer are: (a) Can a complex intervention combining community participation and mindfulness-based training reduce problematic video game use and the risk of video game addiction in adolescents?; (b) Does classroom-based mindfulness training improve adolescents' mindfulness, emotional well-being, and self-regulation?; (c) Does mindfulness training for adults improve their own well-being and their ability to support adolescents in adopting healthier leisure habits?; and (d) Can a participatory, community-based approach increase adolescents' awareness and use of active, screen-free leisure alternatives?

Researchers will compare adolescents from intervention schools with adolescents from control schools, where no intervention is implemented and only data are collected. Outcomes will be measured at three time points: before the intervention, after the intervention, and at follow-up, in order to assess changes over time and the sustainability of effects.

Participants will:

• Complete questionnaires at different time points assessing video game use, possible video game addiction, mindfulness, psychological well-being, impulsivity, cyberbullying, social support, and online experiences.
• Take part in a community-based component in which adolescents actively participate in identifying, designing, and promoting leisure activities without screens in their local environment. This process includes the creation of a school-based community group composed of adolescents, teachers, health professionals, family representatives, and community members. Adolescents are involved in participatory activities to map community resources and co-design attractive leisure options, which are later implemented and shared with families and the wider community.
• Participate in a group-based mindfulness and emotional development program delivered in the classroom during school hours. This program consists of structured sessions based on established mindfulness protocols and is designed to help adolescents develop attention skills, emotional awareness, stress management, and self-regulation.
• Access an individual, online mindfulness and emotional regulation program (adults only), which combines mindfulness practices and cognitive-behavioral strategies. This self-guided program is completed over several weeks and aims to improve adults' well-being and provide tools to better support adolescents.

By integrating community action, school-based intervention, and adult involvement, this study seeks to evaluate a comprehensive and sustainable approach to preventing problematic video game use and promoting healthier lifestyles during adolescence

Video games are a common form of leisure among adolescents and can have positive effects when used in moderation. However, excessive or problematic use during adolescence has been associated with negative consequences for physical health, emotional well-being, academic performance, and social relationships. In recent years, concerns have increased regarding the risk of problematic video game use and potential video game addiction, particularly in relation to online gaming, prolonged screen time, and difficulties in emotional self-regulation.

Adolescence is a critical developmental period in which habits related to leisure, coping strategies, and emotional regulation are established. Research suggests that problematic video game use does not depend solely on individual behavior, but is influenced by a combination of personal, family, school, and community factors.

The widespread use of video games among adolescents has increased substantially in recent years, making digital gaming one of the main forms of leisure during this developmental stage. While video games can offer entertainment and social interaction, research has shown that excessive or poorly regulated use may be associated with sedentary behavior, sleep disturbances, emotional difficulties, academic problems, and impaired social relationships. In response to these concerns, problematic video game use has been increasingly examined as a public health and mental health issue in adolescence.

The present study is grounded in current scientific evidence indicating that problematic video game use is influenced by multiple interacting factors. These include individual characteristics such as impulsivity, emotional regulation, and stress, as well as contextual factors related to family functioning, school environment, community resources, and the design features of contemporary video games. The study also draws on evidence supporting mindfulness-based approaches as promising tools for improving self-control, emotional awareness, and well-being in adolescents and adults.

The study follows a longitudinal, controlled design with an intervention group and a control group. Participating schools are located in different basic health zones in Pontevedra (Galicia, Spain), representing urban, semi-urban, rural, and coastal contexts. Schools in the intervention and control groups are selected to ensure comparable sociodemographic characteristics.

Allocation is performed at the classroom level, and blinding of participants is not feasible due to the nature of the intervention. However, blinding is applied during data analysis. The study is embedded within the official school planning framework, facilitating institutional support and high participation rates.

The planned sample includes approximately 1,104 adolescents, with 552 students in the intervention group and 552 in the control group. Sample size calculations are based on detecting a 35% reduction in problematic video game use and potential video game addiction, assuming an initial prevalence of approximately 18%. Calculations were performed using standard epidemiological software.

In addition to adolescents, the study includes adults from the adolescents' environment, such as family members, teachers, health professionals, and community representatives, who participate in specific components of the intervention.

The intervention is structured around three coordinated components: a community-based component, a group-based component for adolescents, and an individual component for adults. These components are implemented sequentially and are designed to reinforce each other.

The community-based component aims to promote active, shared, and screen-free leisure activities within the adolescents' local environment. A central element is the creation of a school-based community group composed of adolescents, teachers, health professionals, family representatives, and community members.

This group is trained in participatory action research methodologies, enabling adolescents to actively identify community assets, barriers, and opportunities related to leisure activities. Adolescents participate in mapping local resources, prioritizing feasible and attractive alternatives to video gaming, and co-designing leisure activities adapted to their context.

The selected activities are implemented through organized community events and leisure sessions, which may include physical, recreational, or volunteer activities. Dissemination activities are conducted to share experiences and outcomes with families, schools, health services, and the broader community. This component emphasizes adolescent leadership, shared decision-making, and sustainability.

The group-based component consists of a classroom-based mindfulness and emotional development program delivered to adolescents in intervention schools. The program is based on internationally recognized mindfulness protocols and is adapted to the educational context and developmental stage of early adolescence.

The program is delivered through structured sessions during school hours, focusing on the development of attention, emotional awareness, stress management, and self-regulation. Sessions combine experiential practices, reflective activities, and age-appropriate discussions. No minimum number of participants is required, and adaptations are made to ensure accessibility for students with special educational needs.

This component is designed to address individual factors associated with problematic video game use, such as impulsivity and emotional dysregulation, while complementing the community-based activities.

The individual component targets adults from the adolescents' environment, including family members and members of the community group. It consists of an online, self-guided program combining mindfulness practices and cognitive-behavioral strategies.

The program is delivered through digital platforms and completed over several weeks. It includes structured modules with guided practices, psychoeducational content, and exercises aimed at improving emotional regulation, stress management, and well-being. Participation is voluntary and requires informed consent.

This component is intended to strengthen the supportive role of adults and to promote consistency between adolescents' environments, reinforcing healthy leisure habits and emotional skills.

Data are collected at three time points: baseline (pre-intervention), post-intervention, and follow-up. Validated instruments are used to assess problematic video game use, potential video game addiction, mindfulness, psychological well-being, impulsivity, cyberbullying, social support, and online experiences. Adult participants complete measures related to mindfulness.

Adherence to each intervention component is systematically recorded using attendance logs and digital access records, allowing assessment of engagement and dose-response relationships.

Data are managed using a secure electronic data capture system with pseudonymization and separation of identifying information. This ensures compliance with data protection regulations and supports data integrity.

Statistical analyses are conducted using multilevel mixed-effects models to account for the hierarchical structure of the data (students nested within classrooms and schools) and repeated measurements over time. Analyses compare changes between intervention and control groups while adjusting for relevant covariates such as age, sex, adherence, and contextual factors.

Predefined criteria for intervention success are established based on relative improvements in primary and secondary outcomes, informed by the absence of closely comparable prior interventions.

The study complies with ethical principles for research involving minors, including informed consent procedures and special protections for confidentiality and inclusion. Activities are adapted to ensure accessibility for participants with special educational needs.

Dissemination is integrated throughout the study, with structured activities aimed at families, schools, health services, and the community. Study data are prepared following FAIR principles to support transparency and future research.

Inclusion Criteria:

• FOR ADOLESCENTS:
• Age between 11 and 15 years at the time of enrollment.
• Enrollment in the first year of secondary education in a participating school.
• Attendance in a classroom assigned to either the intervention or control group.
• Provision of written informed consent by a parent or legal guardian.
• Provision of assent by the adolescent, when applicable according to age and regulations (14 years old).
• FOR ADULTS:
• Being a parent, legal guardian, teacher, health professional, or community member linked to an adolescent in the intervention group.
• Willingness to participate in the adult component of the study.
• Provision of written informed consent.

Exclusion Criteria:

• FOR ADOLESCENTS:
• Age below 11 years or above 15 years at the time of enrollment.
• Lack of written informed consent from a parent or legal guardian.
• Refusal or inability of the adolescent to provide assent, when applicable.
• Inability to complete the study questionnaires due to language or comprehension barriers that cannot be reasonably accommodated.
• FOR ADULTS:
• Lack of written informed consent.
• Inability to access or use the digital platform required for the online intervention.
• Inability to complete study questionnaires due to language or comprehension barriers.