Psychological distress across successive assessment periods of the rotating medical internship: burnout, anxiety, and depression among medical interns in Ecuador: a repeated cross-sectional study

Introduction Medical internship is a critical transition stage characterized by severe clinical demands and substantial psychosocial vulnerability. Methods A repeated cross-sectional study with four independent assessment waves (baseline, 3, 6, and 9 months) was conducted at Hospital General del Sur de Quito. Responses were anonymous and could not be linked across waves; repeated participation by the same intern cannot be excluded. MBI, HAM-A, and PHQ-9 validated scales were administered; the HAM-A was self-administered in a modified 13-item version. Multivariable linear and logistic regression and sex-stratified analyses were performed. Adjusted trend tests were Holm-corrected for multiplicity; all other analyses, including sex-stratified ones, were exploratory. Results Overall, 206 independent assessments were analyzed. Moderate-or-greater depression prevalence was 27.8% at baseline, 50.0% at 3 months, 58.1% at 6 months, and 56.0% at 9 months ( p = 0.002); the adjusted OR was 1.75 per period ( p = 0.001), an average log-odds gradient that does not imply a monotonic increase given the plateau after 6 months. High emotional exhaustion was more prevalent at 9 months than at baseline (68.0% vs. 32.2%; p < 0.001; β = 4.19 per period), and high depersonalization at 3 months than at baseline (43.8% vs. 21.1%; p = 0.035). Low personal accomplishment was 31.1% at baseline and 44.0% at 9 months ( p = 0.019; exploratory). Anxiety scores were higher at later periods ( β = 2.28, p < 0.001). Exploratory sex-stratified analyses, based on small, imprecise subgroups, suggested a steeper gradient among men for anxiety (OR = 3.46, p = 0.007) and depression (OR = 2.73, p = 0.014); these do not constitute evidence of a sex-specific effect. After Holm correction, lower personal accomplishment (adjusted p = 0.080) and overall burnout were not significant. Discussion This repeated cross-sectional study showed greater distress at later internship assessment periods (independent samples, not individual change), with higher depressive symptoms, anxiety, and emotional exhaustion; lower personal accomplishment did not remain significant after correction. Findings support early, sustained institutional strategies to monitor and protect interns' mental health. They are associational and establish neither within-person change nor causality.