This is a popular psychological book that popularizes psychological knowledge by explaining cases of psychological disorders. Since its release in 2006, the original English version has occupied the top spot on the European and American psychology bestseller lists for a long time. It is still firmly in the top ten of Amazon's "Nursing Psychiatry and Mental Health" list in the United States. It has been highly recommended by authoritative organizations such as the American Psychological Association, the American Psychiatric Association, and the Canadian Psychological Association. The author, Dr. Morrison, not only popularizes the scientific definition of mental illness from theoretical knowledge, but also gives you an in-depth understanding of the different impacts of different mental illnesses on people's daily lives through more than 100 real cases. The book introduces the basic characteristics of psychological diseases such as depression, mania, anxiety, fear, obsessive-compulsive disorder, and dementia. It also describes in detail the real situations when patients undergo psychological consultation. On the one hand, this book unveils the mystery of psychological counseling and psychological diagnosis, allowing the general public to see how professionals use scientific methods to evaluate patients' mental health problems; on the other hand, it also systematically and rigorously introduces the scientific methods of psychological diagnosis, helping psychology-related practitioners to establish professional diagnostic thinking. Therefore, this book is not only an interesting popular science book for psychology enthusiasts, but also can be used as a desk reference book for professionals and a teaching aid for professional examinations.