Abstract
OBJECTIVE: To culturally adapt the Patient Health Questionnaire (PHQ-9) for Aymara-speaking populations in Peru and Bolivia and to evaluate its psychometric properties. MATERIALS AND METHODS: A study was conducted with a non-probabilistic sample of 1,607 Aymara speakers from Peru (n = 969) and Bolivia (n = 638), aged 18 to 74 years, with both sexes represented. In the first phase, forward and backward translations were carried out, followed by expert review to ensure cultural contextualization, and focus group with Aymara speakers. In the second phase, internal structure validity, external criterion validity, group-based invariance, and reliability were assessed. RESULTS: The Aymara PHQ-9 demonstrated a unidimensional factor structure with satisfactory fit indices (CFI & TLI > 0.95 and RMSEA & SRMR < 0.08) across Aymara variants in Peru and Bolivia. Measurement invariance was established across age, sex, residential area, education level, and marital status. External validity revealed significant relationships with the GAD-7 and WHO-5. Both country-specific versions showed high reliability coefficients (Peru α = 0.847 to 0.849; Bolivia ω = 0.943 to 0.942). CONCLUSIONS: The Aymara PHQ-9 for Peru and Bolivia demonstrated robust internal structure validity, external validity, measurement invariance, and reliability. This version is therefore recommended for depression screening among Aymara populations. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40359-026-03972-1.