The goal of this clinical trial is to see if a specific intervention program that uses virtual reality (VR) helps young people reduce aggressive behavior more than the same program without VR or their usual treatment. The study will also look at how the program affects anger, impulsivity, emotional control, and how participants understand and handle conflicts with others.

The main questions the study wants to answer are:

• Does the intervention program with VR help young people reduce aggressive behavior more than the same program without VR or just their usual treatment?
• What changes in the mind and body are linked to improvements in aggressive behavior and emotional control?

The researchers will compare three groups of young people:

• Usual treatment plus the 4-session intervention program with VR.
• Usual treatment plus the 4-session intervention program without VR.
• Usual treatment only.

Participants will:

• Attend 4 individual sessions lasting 1 to 1.5 hours, once a week.
• Take part in activities to learn how to recognize emotions, understand conflict situations, and manage anger and impulsivity.
• Complete questionnaires about aggressive behavior, anger, impulsivity, emotional control, and how they interpret conflicts.
• Have their aggressive behavior recorded through disciplinary reports at the center.
• Provide saliva samples before and after sessions to measure hormones related to stress and aggression.
• Wear a chest band that measures heart rate and a headset that records brain activity during the VR activities.

All data will be kept confidential, and the identities of participants will be protected at all times.

Juvenile violence constitutes a major public health and social challenge, with significant individual, societal, and economic consequences. In Spain, violent offenses committed by adolescents account for approximately 5% of all registered crimes, and official data indicate a marked increase in youth violence over the past decade. Both perpetrators and victims are frequently minors, particularly in contexts such as bullying, physical assault, dating violence, and youth gang-related offenses. Beyond its immediate impact on victims, juvenile violence is strongly associated with adverse developmental trajectories for offenders, including academic failure, social exclusion, mental health problems, and an elevated risk of persistent criminal behavior into adulthood.

Adolescence represents a critical developmental period characterized by heightened emotional reactivity, ongoing neurobiological maturation, and increased sensitivity to environmental influences. Individuals who display stable patterns of violent and antisocial behavior in adulthood often begin exhibiting aggressive conduct during adolescence. Consequently, early identification and intervention with young offenders are essential to prevent the consolidation and chronicity of aggressive behaviors. Interventions targeting this population have the potential not only to improve individual outcomes but also to reduce recidivism and enhance public safety.

To date, a range of psychosocial interventions aimed at reducing aggression in adolescents has demonstrated some degree of effectiveness. Programs focusing on cognitive-behavioral strategies, emotional regulation, social skills training, and problem-solving have yielded positive outcomes, particularly when delivered in a targeted and time-limited manner to high-risk youth. However, meta-analytic evidence suggests that the magnitude of these effects is generally small to moderate, highlighting important limitations in current treatment approaches. Factors such as low treatment adherence, reduced motivation, difficulties in generalizing learned skills to real-life situations, and limited engagement with traditional therapeutic formats may partially account for these modest outcomes, especially in adolescents involved in the juvenile justice system.

In response to these challenges, there is growing interest in the integration of innovative technological tools to enhance the effectiveness of psychosocial interventions. Virtual Reality (VR) has emerged as a promising therapeutic modality due to its capacity to generate immersive, interactive, and ecologically valid environments that simulate real-world situations. VR facilitates experiential learning by allowing users to engage in realistic scenarios while maintaining a high level of experimental and clinical control. This technology has demonstrated effectiveness as an adjunctive tool in psychological treatments, particularly for anxiety disorders, phobias, post-traumatic stress disorder, and substance use disorders. More recently, VR-based interventions have been developed to address aggression-related processes, including emotional awareness, physiological arousal regulation, empathy enhancement, and assertive interpersonal skills.

Despite these promising developments, the empirical evidence supporting the use of VR in the treatment of juvenile violence remains limited. Existing VR-based programs often focus on specific components (e.g., empathy induction or anger management), are not fully integrated into structured therapeutic protocols, or have not been specifically designed for adolescent populations. Moreover, few studies have evaluated the added value of VR when embedded within multicomponent interventions, and even fewer have been conducted within secure or semi-secure juvenile justice settings or adapted to the Spanish sociocultural context. As a result, there is a clear need for rigorous, well-controlled studies that assess the effectiveness of VR-enhanced interventions for aggressive behavior in youth offenders.

The present project seeks to address these gaps by conducting a randomized controlled trial (RCT) with three parallel arms in adolescents residing in three juvenile offender facilities. The primary objective of the study is to evaluate whether a multicomponent psychosocial intervention incorporating Virtual Reality is more effective in reducing aggressive behavior than both treatment as usual (TAU) and an active control intervention. Secondary objectives include examining changes in relevant psychological variables (e.g., emotional regulation, impulsivity, empathy, hostility, and social problem-solving) and neurophysiological biomarkers associated with aggression, as well as identifying predictors of treatment response and therapeutic prognosis.

The study will employ a three-arm randomized controlled design with parallel groups. Participants will be recruited from three juvenile offender facilities and randomly assigned to one of the following conditions:

1. Treatment as Usual (TAU): Participants will receive the standard intervention routinely provided at the facilities.
2. Active Control Intervention (General Intervention): Participants will receive a structured multicomponent intervention of 4 training sessions.
3. Multicomponent Intervention with Virtual Reality: Participants will receive the same structured psychosocial intervention as the active control group, supplemented with VR-based modules specifically designed to address aggression-related processes. These modules will provide immersive simulations of high-risk interpersonal situations, allowing participants to practice. This arm is structured in the same 4 training sessions.

Randomization will be conducted at the individual level, and allocation concealment procedures will be implemented to minimize selection bias. Outcome assessors will be blinded to group assignment whenever feasible. The primary outcome of the study will be the reduction of aggressive behavior, The ethical conduct of the study will adhere to national and international guidelines for research involving minors and justice-involved populations. Informed consent will be obtained from participants and their legal guardians, and all procedures will prioritize participant safety, confidentiality, and well-being.

From a social perspective, the project has significant relevance. Effective interventions for juvenile offenders can reduce recidivism, improve reintegration outcomes, and decrease the long-term societal costs associated with violence and criminal behavior. By rigorously evaluating an innovative VR-enhanced intervention, this study has the potential to inform evidence-based practice within juvenile justice systems and to support the implementation of more effective, engaging, and developmentally appropriate treatment programs.

This project is expected to make several key contributions to the field. First, it will provide high-quality empirical evidence regarding the effectiveness of a multicomponent VR-enhanced intervention compared to both TAU and active control condition. Second, it will contribute to the understanding of psychological and neurophysiological mechanisms underlying changes in aggressive behavior among adolescents. Third, by employing a novel VR software specifically designed for juvenile offenders and adapted to the Spanish context, the study will offer a scalable and transferable intervention model with potential applicability in other settings.

In summary, this randomized controlled trial aims to advance both scientific knowledge and clinical practice by addressing a pressing social problem through the integration of innovative technology and evidence-based psychological intervention.

In addition, this project brings together two entities: the GINSO association, the Innovae Group company that creates VR software, and the university research team. The GINSO Association has more than 20 years of experience in managing intervention programs aimed at minors and young people in vulnerable situations. It has a comprehensive approach that encompasses juvenile justice, child protection, and child and adolescent mental health, with the treatment of violence being a cross-cutting objective in all its programs. The results of the study could improve the organization's practices in several ways. First, if the evaluation shows a significant improvement in the effectiveness of the programs, confirming that virtual reality (VR) is a useful and complementary approach to standard treatment, this technology could be integrated into general intervention programs. Second, updating tools would not only increase the effectiveness of treatments but also contribute to the training of the association's professionals, improving their technical skills to meet the needs of minors in the centers. In this context, it should be noted that there are specific lines of funding aimed at the technification and digitization of the third sector, promoted at both the national and European levels. In addition, this project brings together two entities: the GINSO association, the Innovae Group company that creates VR software, and the university research team. The GINSO Association has more than 20 years of experience in managing intervention programs aimed at vulnerable minors and young people. It has a comprehensive approach that encompasses juvenile justice, child protection, and child and adolescent mental health.

The project will also allow UFV to transfer knowledge, impacting not only the academic sphere but also contributing to the strengthening of professional practices in this sector.

Based on the collaboration between these entities, new VR scenarios could be developed to address specific forms of violence, such as bullying and gender violence, as well as other antisocial behavior problems, such as drug use. Finally, the results of the research may influence public policies related to the treatment of youth violence. It is essential to prioritize access to innovative treatments, especially for people with limited economic resources, as is the case for most users of the centers managed by the GINSO Association.

Inclusion Criteria:

• 12-18 years old at the moment of recruitment and allocation.
• Minimum facility stay of 6 months since the begining of the study.
• Documented records of recent aggresive behavior.

Exclusion Criteria:

• Neurological disorder, brain injury, or psyquiatric pathology that affects cognitive functions or advises against use of virtual reality.
• Not being fluent in Spanish.

Individual participant data will not be shared publicly due to the highly vulnerable nature of the study population, which consists of minors (aged 12-18 years) under judicial custody. The data collected are sensitive and include mental health information, psychophysiological measures, and records of aggressive behavior within the juvenile justice system. Informed consent signed by participants and their legal guardians restricts data use to the research teams of Universidad Francisco de Vitoria and GINSO. Restricting data access ensures compliance with data protection regulations (GDPR and Spanish data protection law) and protects participants' privacy. In line with the principle of responsible openness, study results will be disseminated in aggregated and anonymized form. Any exceptional access to anonymized data would require a justified request to the Principal Investigator and evaluation under scientific, ethical, and legal criteria.