Abstract
Background: Resistant major depression (RMD) is characterized by persistent depressive symptoms despite adequate pharmacological treatment, leading to functional impairment and increased physical comorbidity. Lifestyle interventions, particularly physical activity, are promising adjuncts, yet factors influencing engagement remain poorly understood. Methods: A purposive sampling approach and thematic analysis informed by a socioecological framework were employed to explore participants' lived experiences after completing a 12-week supervised combined exercise program. Semi-structured interviews were thematically analyzed. Results: Engagement was influenced by three main themes: intrapersonal (symptoms, lifestyle, medication, program expectations), interpersonal (family, peers, healthcare professionals), and environmental (program location, schedule, session design) factors. Motivation was shaped by emotional, physical, and social goals, while barriers included fatigue, anhedonia, and side effects of medication. Conclusions: Engagement in exercise interventions for RMD is shaped by the interaction of personal, social, and environmental factors. Understanding lived experiences can inform the design of person-centered, sustainable interventions.