This case study examines the mental health of Mary, a 41-year-old woman experiencing depression. It explores the correlation between mental and physical health, diagnosing Mary with recurrent major depressive disorder based on DSM-IV and ICD-10 criteria. The study delves into treatment options, including antidepressant medications like SSRIs and cognitive behavioral therapy, highlighting the significance of personal recovery. It emphasizes the implications for nursing practice, such as building therapeutic relationships and promoting healthy behaviors. The analysis underscores the importance of understanding the link between mental and physical well-being to improve the quality of life for individuals with mental illness. The case study also addresses the role of nurses in patient care, medication compliance, and lifestyle choices, providing a holistic approach to mental health treatment.