Objective: evaluate the impact of a Life Skills Training (LST) intervention on substance use intention by analyzing changes in neuropsychological organization and psychological regulation processes in adolescents living in social assistance institutions.Methodology Design: Parallel-group randomized controlled trial with a 1:1 allocation ratio. Participants: 20 adolescents aged 12 to 17 with a minimum of 3 months of residence in foster care homes in Mexicali, Baja California.Intervention: The experimental group will undergo 8 sessions (60 minutes each) of LST, while the control group will receive a traditional psychoeducational intervention of the same duration.Key Measures: Electroencephalography (EEG) will be used to monitor cortical maturation (Alpha/Theta power) and frontal asymmetry. Clinical scales including DERS, DUSI, BANFE-2, and substance use intention questionnaires will also be administered.RationaleIn Mexico, the average age of onset for substance use has dropped to 12-13 years. Institutionalized adolescents face heightened vulnerability due to histories of trauma, neglect, and environmental exposure to high-lethality substances such as fentanyl and methamphetamines in the border region

Adolescence is a vital stage characterized by biopsychosocial changes, marking the transition from childhood to adulthood. Recent decades have shown demographic and epidemiological shifts associated with morbidity and mortality in this group. Health problems in this age range are often determined by risk behaviors such as substance use, sedentary lifestyles, poor nutrition, and risky sexual behaviors.During this stage, impulsivity, sensation-seeking, and exposure to social pressure increase the likelihood of engaging in risk behaviors. Studies based on the Theory of Planned Behavior (Ajzen, 1991) suggest that substance use intention-a cognitive, emotional, and social predisposition-is a key predictor of early consumption. This is particularly critical in adolescents due to the incomplete development of the prefrontal cortex, which limits inhibitory control and the ability to evaluate future consequences.Scientific evidence indicates that preventive programs based on life skills (LS)-such as self-regulation, decision-making, and peer pressure resistance-can effectively delay and reduce drug use. For example, Italian adaptations of LS training showed significant reductions in alcohol and tobacco use.Context in Mexico and Baja California National Level: The average age of drug use onset dropped from 20.7 years (2002) to 15.3 years (2023) among those receiving treatment. Common starter substances include alcohol (38.6%), tobacco (31.4%), and marijuana (16.8%). Methamphetamine use has increased by 218% between 2013 and 2022.Regional Level (Baja California): Methamphetamine is the primary health threat, representing 56.5% of specialized treatment demands. Fentanyl cases tripled from 3.8% in 2022 to 10.9% in 2024.Mexicali: 48.1% of the population identifies "street drug use" as the most frequent criminal behavior in their environment. Institutionalized adolescents in this region face high environmental availability of substances, increasing the risk of early use.

Problem Statement Research Question What are the psychological and neuropsychological effects of a life-skills-based intervention in institutionalized adolescents?

Specific Questions What is the effect of a Life Skills (LS) intervention on brain function organization?

What is the effect of an LS-based intervention on social skills?

What is the effect of a Life Skills intervention on inhibitory control?

What is the effect of an LS-based intervention on emotional regulation?

What effect do LS-based interventions generate on substance use intention?

Background Adolescence is a vital stage characterized by biopsychosocial changes, marking the transition from childhood to adulthood. Recent decades have shown demographic and epidemiological shifts associated with morbidity and mortality in this group. Health problems in this age range are often determined by risk behaviors such as substance use, sedentary lifestyles, poor nutrition, and risky sexual behaviors.

During this stage, impulsivity, sensation-seeking, and exposure to social pressure increase the likelihood of engaging in risk behaviors. Studies based on the Theory of Planned Behavior (Ajzen, suggest that substance use intention-a cognitive, emotional, and social predisposition-is a key predictor of early consumption. This is particularly critical in adolescents due to the incomplete development of the prefrontal cortex, which limits inhibitory control and the ability to evaluate future consequences.

Scientific evidence indicates that preventive programs based on life skills (LS)-such as self-regulation, decision-making, and peer pressure resistance-can effectively delay and reduce drug use. For example, Italian adaptations of LS training showed significant reductions in alcohol and tobacco use Context in Mexico and Baja California National Level: The average age of drug use onset dropped from 20.7 years (2002) to 15.3 years (2023) among those receiving treatment. Common starter substances include alcohol (38.6%), tobacco (31.4%), and marijuana (16.8%). Methamphetamine use has increased by 218% between 2013 and 2022.

Regional Level (Baja California): Methamphetamine is the primary health threat, representing 56.5% of specialized treatment demands. Fentanyl cases tripled from 3.8% in 2022 to 10.9% in 2024. Mexicali: 48.1% of the population identifies "street drug use" as the most frequent criminal behavior in their environment. Institutionalized adolescents in this region face high environmental availability of substances, increasing the risk of early use.

Objectives General Objective To evaluate the impact of a Life Skills (LS) intervention on substance use intention by analyzing changes in neuropsychological organization and psychological regulation processes in institutionalized adolescents.

Specific Objectives Analyze changes in general neurocognitive functioning after the LS intervention.

Determine the effect of the LS program on the participants' social skills. Evaluate the efficacy of the intervention in improving inhibitory control. Identify modifications in emotional regulation capabilities. Contrast pre- and post-intervention levels of substance use intention. JustificationAdolescents are vulnerable due to incomplete brain development, specifically in areas related to decision-making and inhibitory control. Institutionalized youth (those in group homes/shelters) face higher risks because of prior experiences with neglect, abandonment, family disintegration, or abuse. These factors negatively impact emotional self-regulation and social skills.Intervening in the intention to consume-the psychological stage preceding the behavior-has high preventive value. This study will contribute to the social protection of a vulnerable group by strengthening protective factors and potentially improving institutional coexistence and school performance.FeasibilityAccess: Participants are in a residential setting, which ensures availability for pre-tests, sessions, and post-tests, minimizing drop-out rates.Resources: The psychoeducational intervention is low-cost and does not require expensive technology. The researcher is supported by a National Graduate Scholarship (SECIHTI).Competencies: The researcher has the academic training in psychology and methodology required to work with vulnerable populations.MethodologyDesign: Parallel randomized clinical trial with a 1:1 allocation.Groups:Experimental Group: 8 sessions (60 min each) of Life Skills training.Control Group: 8 sessions of traditional psychoeducational intervention.Participants: 20 adolescents (ages 12-17) residing in non-profit group homes in Mexicali.

Inclusion Criteria:

• Adolescents aged 12 to 17 who have lived in the participating children's home.
• Ability to understand and respond to the tests and questionnaires administered during the study.
• Approval and signature of the director or legal guardians of the social welfare institutions on the informed consent form.

Informed consent of the adolescent.

Exclusion Criteria:

• Adolescents diagnosed with externalizing disorders, intellectual disabilities, or severe or serious psychiatric disorders that prevent them from understanding the intervention protocol.
• Adolescents who are undergoing administrative processes such as family reintegration or imminent relocation that make it difficult to complete the assessments.
• Participation in other studies that interfere with the application of the assessment instruments.
• Situations of acute emotional, medical, or behavioral crisis observed by the administrative staff of social welfare institutions.