We appreciate all the kind remarks and suggestions from the many medical students over the past 3 years. Your positive reception has been an incredible encouragement, especially in light of the short life of the Case Files® series. In this sixth edition of Case Files®: Psychiatry, the basic format of the cases has been retained, but we have updated medications, cases, and questions in the book. We grouped the cases in the same order as they may be found in the DSM-5 categories in the book. For example, neurodevelopmental disorders such as intellectual disability and attention deficit hyperactivity disorder come first, and the personality and paraphilic disorders come last. This will allow for the ability to compare and contrast related disorders side by side, something that has been requested by our readers. The case listing and the index will allow a student to quickly reference similar cases for the sake of comparison as well. We have used entrustable professional activities (EPA) corresponding to the learning objectives. The summary of the case scenarios are in bullet style to allow for easier reading. The multiple-choice questions have been carefully reviewed and rewritten to ensure that they comply with the National Board and USMLE Step 2 CK format. We have also revised our review questions to the book, and a more uniform format has been added to each case. New psychiatric medications have been introduced too. In using this sixth edition, we hope that the reader will continue to enjoy learning psychiatry through the simulated clinical cases. It is certainly a privilege to teach so many students, and it is with humility that we present this edition.