Epidemiological data are the first step in estimating the impact of a health problem. Comorbidity of mental and physical disorders is a field that recently has been the focus of increasing attention. This book addresses this timely topic using epidemiological data regarding the main chronic physical conditions (pain, stroke, coronary artery disease, hypertension, diabetes, asthma, tuberculosis, chronic lung disease, parasitic disease, gastrointestinal ulcer, thyroid disease, neurological disorders, HIV infection, cancer) as well as psychiatric conditions, including depressive, anxiety, and substance use disorders. Importantly, the book presents data gathered using similar methodologies from 17 countries (10 developed countries, including the United States, and seven developing countries) in six continents in conjunction with the World Health Organization (WHO) World Mental Health Survey Initiative, and thus it gives the reader a truly global perspective. This book not only reports data, it has been written using a well-integrated observational and theoretical perspective. Using a stimulating approach to the concept of the "mind-body duality," the authors try to answer questions about the relationship between the mind and body and their mutual influence as well as their relevance to health, disabilities, mortality, and social status. In summary, this book comprises a huge compilation of data from the most reliable surveys in the world. It can serve as a basis to generate hypotheses and devise clinical and public health solutions to improve the health of patients who suffer from these highly prevalent chronic mental and physical diseases.