Validation and Reliability of the Spanish Internet Addiction Test-7 (IAT-7) for Adolescents

Problematic internet use has been consistently associated with different adverse effects on bio-psycho-social health outcomes. However, there is a lack of consensus in the definition and measures. This study aimed to translate and culturally adapt the Internet Addiction Test-Short Form (IAT-7) into Spanish and to evaluate its validity and reliability among adolescents. A total of 783 participants aged 12-18 years completed the questionnaires while 106 answered again two months later to assess test-retest reliability. Construct validity was examined using confirmatory factor analysis to test the two-factor structure. Convergent and discriminant validity, reliability, and invariance were analyzed. All items showed significant standardized loadings (0.55-0.85; p < 0.001), and fit indices supported the two-factor model. Both factors showed adequate convergent validity, while moderate correlation between factors (ρ = 0.667) supported discriminant validity. Test-retest reliability was strong (ICC = 0.814), and internal consistency was satisfactory (Cronbach's α = 0.850; McDonald's ω = 0.853). Furthermore, measurement invariance analyses supported the equivalence of the scale across gender and age. In conclusion, the Spanish IAT-7 is a valid and reliable instrument for assessing problematic internet use in adolescents aged 12-18 years.