“I think, therefore I suffer,” or when thinking too much brings harm. This is the leitmotif of the book. According to the author, this is a real pandemic that happened in the modern world. The belief that with the help of rational reasoning one can solve all issues and manage one’s life leads to the fact that excessive thinking can create problems for a person that he is not able to cope with on his own. The reader will become acquainted with various types of doubts that overcome a person in different life situations, and using the example of clinical cases, the author introduces readers to his method of using therapeutic doubt, which helps to cope with emerging difficulties. The innovative approach of J. Nardone, known as Brief Strategic Therapy, allows you to see how the most complex mental problems can be solved with the help of simple but effective solutions. The book is intended for psychotherapists, psychologists, doctors, students of these specialties and other readers interested in modern psychology and solving human problems. Scientific editor Ph.D. psychol. Sciences E. Pervysheva. The publishing layout is saved in PDF A4 format.