This article discusses the theory of functionalism and its application in understanding mental state and the concept of sick role. It explores the causal relationship between individuals and their mental state, emphasizing the rights and responsibilities of those who are unwell. The article also highlights the prevalence of depression in women and the evidence-based nursing interventions provided to both male and female patients. Additionally, it examines the role of functionalism in explaining the patterns and trends in health and illness, particularly the higher prevalence of depression and anxiety in women due to social stress and overuse of medications.