Adverse Childhood Experience International Questionnaire–Mexican Spanish Version

1. Abstract

The Adverse Childhood Experience International Questionnaire–Mexican Spanish Version (ACE-IQ Mexican Spanish Version; Casas-Muñoz et al., 2024) is a psychometrically validated, culturally adapted self-report instrument designed to quantify the prevalence, frequency, and severity of adverse childhood experiences (ACEs) among adolescents living in low- and middle-income socioeconomic contexts. Adapted directly from the World Health Organization’s global ACE-IQ initiative, this 47-item multi-dimensional inventory systematically evaluates childhood trauma across expanded ecological domains, moving beyond conventional household dysfunction to capture systemic community violence, peer victimization, and severe structural stressors. Specifically, the instrument assesses nine interrelated developmental adversity domains: living with a household member who uses psychoactive substances; living with a household member experiencing severe mental health disorders; household incarceration; parental loss through death, separation, or desertion; chronic or life-threatening parental physical illness; exposure to domestic, community, and collective violence; physical, psychological, and contact sexual abuse; emotional and physical neglect; and chronic peer bullying victimization.

Methodologically tailored for electronic administration among Mexican youth aged 11 to 19 across 20 federal entities, the scale implements a dual response format: dichotomous recording (Yes/No) for family dysfunction markers, and a four-point ordinal frequency scale (“Never,” “Once,” “A few times,” and “Many times”) alongside a sensitive-item opt-out (“I do not wish to answer”) for interpersonal abuse, neglect, and violence exposure. Robust psychometric evaluation demonstrated exceptional structural validity and internal consistency. Confirmatory factor analysis supported the multidimensional construct fit (χ²(666) = 4187.65, p < .001; Comparative Fit Index [CFI] = 0.95; Root Mean Square Error of Approximation [RMSEA] = 0.03 [95% CI: 0.02–0.03]; Standardized Root Mean Square Residual [SRMR] = 0.06). Reliability estimates for ordinal data demonstrated superior internal consistency, yielding an ordinal Cronbach’s alpha (α) of 0.88 and an ordinal McDonald’s omega (ω) of 0.91. The instrument represents a critical advance for clinical screening, epidemiological surveillance, and trauma-informed health policy across Latin America.

2. Keywords

Adverse Childhood Experiences, ACE-IQ, Mexican Spanish Version, Adolescent Mental Health, Childhood Adversity, Structural Violence, Trauma Assessment, Psychometrics, Confirmatory Factor Analysis, Child Maltreatment, Low- and Middle-Income Countries, Cross-Cultural Adaptation

3. Authors

The adaptation, standardization, and psychometric validation of the Mexican Spanish ACE-IQ were spearheaded by an interdisciplinary team of pediatricians, clinical psychologists, epidemiologists, and public health researchers associated with the National Institute of Pediatrics in Mexico and international child welfare bodies:

• Abigail Casas-Muñoz, MD, PhD — Centro de Estudios Avanzados sobre Violencia-Prevención (CEAVI-P), Instituto Nacional de Pediatría (INP), Mexico City, Mexico.
• Ángel Eduardo Velasco-Rojano, MSc — Centro de Estudios Avanzados sobre Violencia-Prevención (CEAVI-P), Instituto Nacional de Pediatría (INP), Mexico City, Mexico; Primary Corresponding Author (Email: [email protected]).
• Aarón Rodríguez-Caballero, PhD — Research Division, Instituto Nacional de Pediatría, Mexico City, Mexico.
• Eva Prado-Solé, MSc — United Nations Children’s Fund (UNICEF) Mexico Country Office, Mexico City, Mexico.
• Martín G. Álvarez, PhD — Centro de Estudios Avanzados sobre Violencia-Prevención (CEAVI-P), Instituto Nacional de Pediatría, Mexico City, Mexico.

Institutional correspondence regarding the questionnaire and its epidemiological implementation should be directed to the Centro de Estudios Avanzados sobre Violencia-Prevención (CEAVI-P), 1er Torre de Investigación, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Coyoacán, Ciudad de México, C.P. 04530, Mexico.

4. Purpose

The primary clinical, epidemiological, and theoretical objective of the Adverse Childhood Experience International Questionnaire–Mexican Spanish Version is to provide a robust, culturally grounded, and developmentally sensitive measurement instrument capable of identifying the cumulative burden of developmental trauma among adolescents aged 11 to 19 years residing in low- and middle-income regions of Mexico. Early adverse experiences exert enduring neurobiological, socio-emotional, and cognitive impacts across the lifespan. However, standard measurement paradigms developed within high-income Western nations frequently neglect environmental, political, and community-level threats that disproportionately afflict developing economies, such as narco-trafficking skirmishes, systemic gang violence, collective community trauma, and endemic poverty-related household stressors.

From an epidemiological surveillance perspective, the instrument addresses a critical void in Latin American pediatric and psychiatric public health. While traditional screening protocols derived from the seminal Kaiser Permanente and Centers for Disease Control and Prevention (CDC) studies (Felitti et al., 1998) emphasized nuclear family dysfunction (e.g., divorce, maternal battery, domestic alcoholism), youth living in middle-income countries like Mexico frequently face dual vectors of trauma: intra-familial abuse and pervasive extra-familial victimizations. By validating a 47-item instrument that captures both internal household dynamics and external ecological dangers, the scale enables health ministries, public school systems, and nongovernmental organizations such as UNICEF to map the real-world geographic distribution of childhood adversity, quantify structural inequities across diverse states, and deploy targeted, resource-efficient secondary prevention programs.

In clinical psychiatric and psychotherapeutic settings, the scale serves as an essential intake and diagnostic stratifier. Cumulative ACE scores are known to exhibit strong, dose-dependent associations with pediatric depression, non-suicidal self-injury, substance dependence, early sexual debut, academic attrition, and subsequent cardiometabolic dysregulation. By applying a psychometrically sound metric equipped with frequency gradations rather than simple historical presence, clinicians can distinguish isolated, low-frequency stressors from chronic, pervasive poly-victimization. This granular diagnostic stratification informs trauma-informed cognitive behavioral therapy (TF-CBT), guides socio-emotional rehabilitation within social work facilities, and provides objective baselines against which recovery trajectories can be monitored.

5. Psychological Construct

The psychological construct assessed by the instrument is Adverse Childhood Experiences (ACEs), conceptualized through an ecological systems paradigm that encompasses acute, episodic, and chronic toxic stressors occurring from infancy through late adolescence. Rather than viewing developmental trauma as a unidimensional latent variable, the instrument operationalizes ACEs as an extensive, interrelated spectrum of familial, interpersonal, and environmental adversities distributed across nine specific domains:

• Household Substance Abuse: Continuous cohabitation with a primary caregiver or immediate household resident who chronically misuses psychoactive substances, including alcohol, prescription sedatives, illicit narcotics, or inhalants. This dimension captures the domestic instability, parental emotional unavailability, unpredictable erratic behavior, and economic depletion inherent in family addiction cycles.
• Household Mental Illness: Living with adult family members or cohabitants experiencing debilitating, untreated, or severe psychiatric conditions, including major depressive disorder, psychotic spectrum episodes, bipolar disorder, or severe suicidal behavior, which impairs safe parenting practices.
• Incarcerated Household Member: The experience of having a biological parent, guardian, or immediate cohabitant arrested, remanded in custody, or serving a prison sentence, which introduces intense social stigma, abrupt attachment disruption, and domestic economic destitution.
• Parental Loss: Disruptions to early childhood primary attachment networks caused by the death of a mother or father, chronic parental abandonment, long-term geographic desertion, or volatile marital dissolution.
• Parental Serious Physical Illness: Long-term cohabitation with a parent or primary caregiver afflicted by a life-threatening, incapacitating, or terminal medical illness, frequently forcing the adolescent into premature parentification and severe emotional distress.
• Domestic, Community, and Collective Violence: Multi-tiered exposure to physical warfare and interpersonal violence, ranging from witnessing intimate partner violence against a caregiver in the home, to witnessing neighborhood homicides, armed cartel incursions, extortion, police clashes, and widespread community-level armed conflict.
• Physical, Psychological, and Sexual Abuse: Direct, intentional infliction of harm by an adult caregiver, relative, or person of authority. Physical abuse includes beating, burning, bruising, or bodily injury; psychological abuse involves systematic verbal humiliation, terrorizing, threats of abandonment, or scapegoating; and sexual abuse encompasses non-contact exhibitionism, digital grooming, unwanted sexual touching, and forced penetrative sexual assault.
• Physical and Emotional Neglect: Systematic failure of adult caregivers to fulfill essential survival and developmental needs. Physical neglect involves severe deprivation of nutritional food, clean clothing, shelter, supervision, and necessary medical care; emotional neglect entails parental emotional detachment, lack of affection, rejection, and complete indifference to the child’s emotional crises.
• Bullying Victimization: Persistent, asymmetric peer aggression occurring within educational, neighborhood, or digital environments, characterized by repeated verbal insults, social ostracization, physical intimidation, theft, or deliberate malicious humiliation.

6. Theoretical Framework

The conceptual foundation of the instrument synthesizes three major paradigms in contemporary developmental psychopathology: Urie Bronfenbrenner’s Ecological Systems Theory, Attachment Theory (John Bowlby), and the Neurobiology of Toxic Stress (Jack P. Shonkoff and Bruce McEwen).

Under Bronfenbrenner’s ecological model, adolescent development unfolds within nested concentric environmental layers. Traditional Western ACE scales historically restricted their scope to the microsystem of the immediate home environment. The World Health Organization (WHO) and Casas-Muñoz et al. (2024) expanded this framework to recognize that in low- and middle-income societies, the mesosystem (school and peer networks) and the exosystem/macrosystem (neighborhood violence, structural organized crime, socio-economic marginalization) penetrate the adolescent’s daily experience with equal developmental toxicity. When community and peer ecosystems are violent, they compound intra-familial dysfunction, creating an omnipresent climate of existential threat.

Attachment theory elucidates the severe psychological sequelae of familial abuse, neglect, and parental loss. Bowlby posited that infants and youth require a predictable, emotionally attuned, and physically protective secure base to construct internal working models of self-worth and relational trust. When the primary caregiver becomes a source of terror (physical or sexual abuse), unpredictability (substance misuse and untreated mental illness), or absence (incarceration and abandonment), the adolescent cannot establish organized attachment. This relational rupture often results in disorganized attachment styles, emotional dysregulation, impaired mentalization, and chronic hypervigilance.

Finally, the neurobiological model of toxic stress posits that prolonged, frequent activation of the physiological stress-response apparatus—specifically the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary system—in the absence of protective caregiving buffers leads to “allostatic load.” This biological wear-and-tear impairs neurogenesis within the prefrontal cortex, hippocampus, and amygdala, explaining why adolescents exposed to multi-domain ACEs exhibit executive dysfunction, emotional impulsivity, heightened risk for affective disorders, and chronic systemic inflammation.

7. Validity

The construct, factorial, convergent, and content validity of the 47-item instrument were comprehensively evaluated across a diverse, multi-state representative cohort of Mexican adolescents. Content and face validity were established through iterative expert panel reviews comprising child psychiatrists, pediatric trauma specialists, and adolescent psychology researchers. Cultural and linguistic adaptation protocols strictly followed international guidelines established by the World Health Organization, ensuring that expressions, idiomatic terminology, and colloquial Mexican Spanish descriptors of violent and abusive behaviors maintained clinical equivalence without introducing conceptual ambiguity.

Construct validity was rigorously substantiated through large-scale structural equation modeling and confirmatory factor analysis (CFA). In psychometric modeling involving categorical and ordinal indicators, traditional linear maximum likelihood assumptions are violated; consequently, robust estimators (e.g., robust weighted least squares / WLSMV) were implemented. The nine-factor structural configuration demonstrated an excellent fit to empirical data, meeting the conservative benchmark thresholds established by Hu and Bentler: Comparative Fit Index (CFI) > 0.95, Standardized Root Mean Square Residual (SRMR) ≤ 0.08, and Root Mean Square Error of Approximation (RMSEA) ≤ 0.08. Specifically, the observed CFI of 0.95 and RMSEA of 0.03 (95% CI: 0.02–0.03) confirm that the hypothesized multi-dimensional construct accurately reproduces the underlying covariance matrix of adolescent traumatic experiences in Mexico.

Convergent and criterion validity were supported by the strong directional associations identified between cumulative ACE domain scores and adverse adolescent health indices. Elevated exposure to family dysfunction, neglect, and interpersonal violence correlated strongly with internalizing symptoms (major depressive episodes, generalized anxiety, suicidal ideation), externalizing pathology (substance experimentation, conduct difficulties), and academic failure. Discriminant validity across latent factors was confirmed through factor correlation matrices, which revealed that while the nine subscales share meaningful covariance indicative of underlying poly-victimization, each factor maintains distinct empirical independence without excessive collinearity.

8. Reliability

Evaluating internal consistency reliability within instruments featuring mixed dichotomous and polytomous ordinal scales requires specialized psychometric coefficients, as standard Pearson-based Cronbach’s alpha coefficients underestimate true measurement precision when item responses are skewed or bounded. Casas-Muñoz et al. (2024) addressed this by calculating ordinal internal consistency indices based on polychoric correlation matrices.

The scale exhibited outstanding internal consistency across the entire 47-item battery:

• Ordinal Cronbach’s Alpha (α): 0.88, demonstrating that the pool of items possesses robust inter-item homogeneity and minimal measurement noise across diverse adversity domains.
• Ordinal McDonald’s Omega (ω): 0.91, providing a rigorous composite reliability estimate that accommodates varying factor loadings across indicators and reinforces the scale’s structural integrity.

Individual subscale reliabilities were evaluated across the nine dimensions. Interpersonal abuse (physical, psychological, sexual), peer bullying, and domestic violence domains consistently maintained subscale omega coefficients exceeding 0.80. The high overall reliability indicates that the Mexican Spanish Version operates with very low standard errors of measurement (SEM), rendering it appropriate not only for aggregate group-level epidemiological surveillance but also for sensitive clinical evaluations where diagnostic accuracy is paramount.

9. Factor Analysis

The factorial structure of the Mexican Spanish Version was validated via rigorous Confirmatory Factor Analysis (CFA) conducted on an extensive empirical sample of youth aged 11 to 19 spanning 20 Mexican states. Hypothesizing a multidimensional first-order configuration aligned with the WHO expanded ACE taxonomy, the empirical model evaluated nine primary correlated latent factors.

The global goodness-of-fit statistics derived from the confirmatory structural equation model demonstrated exceptional congruence with the empirical data:

• Chi-Square Goodness-of-Fit: χ²(666) = 4187.65, p < .001. Although statistically significant—a standard occurrence in structural equation modeling when sample sizes are large—the ratio of χ² relative to degrees of freedom remained within acceptable limits.
• Comparative Fit Index (CFI): 0.95, indicating that 95% of the covariation in the measured indicators is accounted for by the specified multi-factor model compared to a baseline null model.
• Root Mean Square Error of Approximation (RMSEA): 0.03 (95% Confidence Interval: [0.02, 0.03]), falling well below the strict 0.05 threshold and confirming exceptional parsimonious fit.
• Standardized Root Mean Square Residual (SRMR): 0.06, comfortably beneath the conservative 0.08 cutoff, verifying minimal residual discrepancy between observed and model-implied correlations.

All 47 items demonstrated statistically significant (p < .001) standardized factor loadings onto their designated theoretical dimensions. Loadings for core interpersonal abuse, neglect, domestic violence, and bullying items were strong (λ generally ranging from 0.55 to 0.85), indicating that each item explains a substantial portion of variance in its parent latent construct. Inter-factor correlations were positive and moderate-to-high (ranging from r = 0.30 to r = 0.68), supporting the clinical reality of trauma clustering: adolescents who experience one form of adversity (e.g., domestic violence) face heightened vulnerability to co-occurring adversities (e.g., parental substance misuse, direct physical abuse, and community exposure).

10. Instrument / Measurement Tool

The practical administration characteristics, architectural design, and operational scoring metrics of the inventory are structured as follows:

• Instrument Name: Adverse Childhood Experience International Questionnaire–Mexican Spanish Version (ACE-IQ Mexican Spanish Version).
• Test Type: Standardized, culturally adapted diagnostic and epidemiological screening questionnaire.
• Target Population: Adolescents and youth aged 11 to 19 years; validated across public educational institutions and clinical pediatric centers.
• Total Number of Items: 47 items.
• Administration Modality: Self-administered electronic format via tablets, smartphones, or computers; adaptable to paper-and-pencil or structured clinical interviews when digital hardware is inaccessible.
• Completion Time: Approximately 15 to 25 minutes, depending on the adolescent’s reading literacy level.
• Response Scales:
  • Household Dysfunction Subscales: Dichotomous categorical scale: 0 = No, 1 = Yes.
  • Abuse, Neglect, Violence, and Bullying Subscales: 4-point ordinal frequency scale: 0 = Never (Nunca), 1 = Once (Una vez), 2 = A few times (Pocas veces), 3 = Many times (Muchas veces).
  • Sensitive Item Protection: Every question incorporates a non-penalized opt-out option: “I do not wish to answer” (No deseo responder), ensuring ethical compliance and participant autonomy.
• Scoring Methodologies:
  • Continuous Dimensional Scoring: Raw frequency responses within each subscale are summed to generate continuous severity scores for each of the nine adversity domains.
  • Binary Exposure Threshold Scoring (WHO Standard): Each domain is categorized as “Present” (1) or “Absent” (0) based on established clinical frequency cutoffs (e.g., for severe abuse, endorsement of “Once,” “A few times,” or “Many times” qualifies as positive exposure; for milder or common peer conflicts, higher thresholds like “Many times” are applied).
  • Cumulative ACE Score: Summed binary domains produce an overall cumulative index ranging from 0 to 9, facilitating risk categorization (e.g., Low Risk: 0–1 ACEs; Moderate Risk: 2–3 ACEs; High Risk: 4+ ACEs).

11. Permissions & Fee and Test Year

The Adverse Childhood Experience International Questionnaire–Mexican Spanish Version was published and psychometrically established in 2024. The tool represents an academic adaptation of the public health instrument originally developed by the World Health Organization.

As an instrument developed through academic research funded by public pediatric institutions (Instituto Nacional de Pediatría) and international child protection entities (UNICEF Mexico), the tool is generally intended for non-commercial academic, clinical, and public health research. Researchers, health systems, and clinicians seeking to employ the official Mexican Spanish Version, its full scoring algorithms, or its electronic administration architecture must formally consult the primary research team and corresponding author, Ángel Eduardo Velasco-Rojano (email: [email protected]), and reference the foundational publication (Casas-Muñoz et al., 2024). Commercial licensing, corporate deployment, or inclusion within proprietary diagnostic software suites is strictly prohibited without explicit written authorization from the authors and affiliated institutions.

12. References

Below are foundational academic references documenting the instrument, its theoretical derivation, and relevant psychometric paradigms:

• Casas-Muñoz, A., Velasco-Rojano, Á. E., Rodríguez-Caballero, A., Prado-Solé, E., & Álvarez, M. G. (2024). ACE-IQ extended version validation and ACE’s frequency in Mexican adolescents. Child Abuse & Neglect, 150, Article 106492. https://doi.org/10.1016/j.chiabu.2023.106492
• Felitti, V. J., Anda, R. F., Nordenberg, D., Williamson, D. F., Spitz, A. M., Edwards, V., Koss, M. P., & Marks, J. S. (1998). Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults: The Adverse Childhood Experiences (ACE) Study. American Journal of Preventive Medicine, 14(4), 245–258. https://doi.org/10.1016/S0749-3797(98)00017-8
• World Health Organization. (2018). Adverse Childhood Experiences International Questionnaire (ACE-IQ). World Health Organization. https://www.who.int/publications/m/item/adverse-childhood-experiences-international-questionnaire-(ace-iq)
• McEwen, B. S. (1998). Protective and damaging effects of stress mediators. New England Journal of Medicine, 338(3), 171–179. https://doi.org/10.1056/NEJM199801153380307
• Shonkoff, J. P., Garner, A. S., The Committee on Psychosocial Aspects of Child and Family Health, & The Section on Developmental and Behavioral Pediatrics. (2012). The lifelong effects of early childhood adversity and toxic stress. Pediatrics, 129(1), e232–e246. https://doi.org/10.1542/peds.2011-2663
• Hu, L. T., & Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling: A Multidisciplinary Journal, 6(1), 1–55. https://doi.org/10.1080/10705519909540118

13. Items of the Scale