The BIMSTRESS study protocol: biofeedback, interoception, and mindfulness for stress reduction in a university population

Purpose Stress-related disorders are increasingly prevalent in modern societies and represent a major public mental health concern, particularly in academic environments. While stress is an adaptive response, chronic exposure is associated with psychological distress, impaired well-being, and physiological dysregulation. Non-pharmacological interventions such as heart rate variability biofeedback, interoceptive training, and mindfulness-based programs have shown promise in stress reduction, yet few studies have compared these approaches within a single population using both subjective and objective outcomes. The BIMSTRESS study aims to evaluate the effectiveness of these three interventions in reducing perceived stress in a university population and to explore individual differences in intervention response using psychophysiological and neurophysiological markers. Methods BIMSTRESS is a longitudinal, four-arm, randomized, wait-list controlled trial conducted in a Spanish university community, including students, teaching staff, and administrative personnel. Participants are randomly allocated to heart rate variability biofeedback, interoceptive training, mindfulness-based intervention, or wait-list control. Interventions are delivered over six weeks using a hybrid format that combines weekly laboratory sessions with home-based practice. Assessments are conducted at baseline and post-intervention (7 weeks). The primary outcome is change in perceived stress. Secondary outcomes include psychological well-being, mindfulness, affect, cognitive performance, and physiological measures of stress regulation, including heart rate variability and quantitative electroencephalography. Conclusion The BIMSTRESS study will provide evidence on the comparative effectiveness of scalable, non-invasive stress-reduction interventions in a university setting and will contribute to understanding the role of physiological and neurophysiological markers as potential moderators and mediators of intervention response, informing personalized and preventive approaches to mental health promotion. Clinical trial registration #: NCT06695715