Abstract
BACKGROUND: Medical students face demanding academic requirements, fierce competition, self-doubt and financial concerns contributing to high rates of depression, anxiety, stress, sleep problems and burnout, highlighting a need for effective interventions. We explored an intervention called Enhanced Stress-Resilience Training (ESRT), a modified form of mindfulness training adapted for clinicians, that was applied to medical students for the first time. METHODS: Graduate-entry medical students (N = 118) were randomised to ESRT or an active control condition as part of a registered trial (ISRCTN16324994). A 3 (Time: pre-, post-, and six-month follow-up) × 2 (Group: ESRT, control) mixed design was used to assess changes in psychological flexibility, resilience, and stress reactivity. Due to attrition (T3 n = 47), additional sensitivity analyses, including intention-to-treat and subgroup analyses based on baseline resilience, were conducted. Qualitative data from exit evaluations (n = 25), interviews (n = 12), and focus groups (n = 11) underwent reflexive thematic analysis to explore student experience and contextualise quantitative findings. RESULTS: ESRT users demonstrated increased psychological flexibility scores at post-intervention (p = .001, d = 0.62) and six-months follow-up (p = < 0.001, d = 0.96), and these findings were confirmed in intention-to-treat analysis. Exploratory analyses revealed that those with low baseline resilience who underwent ESRT displayed increased resilience (p = < 0.001, d = 1.86) and decreased stress reactivity (p = < 0.001, d = 1.58) at the six-month follow-up. Qualitative findings highlighted high acceptability, perceived value, and a strong desire for curricular integration, while also revealing barriers to engagement, particularly time constraints. CONCLUSIONS: This study offers new evidence that ESRT may enhance psychological flexibility and resilience, and decrease stress reactivity, especially among more vulnerable students. Sustained effects and positive qualitative feedback suggest that curricular integration could improve feasibility and reach. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-025-07768-6.