ABSTRACT
Introduction: Currently, major depressive disorder generates a high burden of disease in the general population, which is usually higher in medical students. The Patient Health Questionnaire-9 (PHQ-9) is a widely used instrument in the general population to assess the severity of depression in primary care. Objective: To validate the factorial structure of the PHQ-9 questionnaire in human medicine interns at a reference university in Peru. Methods: An observational, cross-sectional and instrumental design was used. We worked with a sample of 343 human medicine interns. From the responses to the questionnaire, the Cronbach's alpha coefficient was calculated, as well as the factorial analysis to determine the construct validity of this instrument in the target population. Results: Cronbach's alpha coefficient was 88.2%, the item/test conversion coefficients presented values greater than 0.5. A value greater than 0.05 was obtained for the chi2 goodness-of-fit test for the model, as well as results greater than 0.9 for the model's goodness-of-fit coefficients. Conclusion: The factorial structure of the PHQ-9 has adequate validity and reliability in the population of human medicine interns.