Depression is a pervasive and debilitating mental health disorder affecting millions worldwide. It is characterized by persistent feelings of sadness, hopelessness, and a lack of interest or pleasure in activities once enjoyed. Furthermore, it is a major risk factor for suicidal thoughts. Depression encompasses a wide range of emotional and physical symptoms, significantly impairing daily functioning. Our environment and lifestyle contribute to the rising prevalence of depression globally.This book delves into various critical issues, including the impact of climate change on depression, the interconnections between anxiety, depression, and stress with changing lifestyles and environmental factors, and the future of depression in a digitalized world. It also examines the effects of pollution on mental health. Additionally, the book offers practical solutions for managing stress, such as yoga, meditation, and fostering an optimistic outlook characterized by a positive attitude and hopeful expectations for the future. Optimism acts as a catalyst for improving our lifestyle and serves as a powerful tool in managing depression.