This book provides brief biographical descriptions of historical and contemporary public figures, with a focus on the behaviors and personality traits that relate to the person's psychological functioning. Diagnostic impressions are provided based on the criteria in the diagnostic manual used by psychiatrists, psychologists, and mental health counselors, the DSM-5. Most of the people described in this book have never been analyzed in terms of current diagnostic criteria. Those whose conditions are diagnosed include politicians, scientists, writers, artists, business leaders, entertainers, and murderers, as well as seven of the most well-known psychological theorists, and four prominent founders of religious movements. The biographical profiles provide enough information for the reader who has some knowledge of psychopathology to be able to form an opinion of whether the person had a mental disorder, and if so which specific disorder it might be. Professional clinicians can use the case studies to compare their diagnostic impressions with those of the author. Students in mental health counseling, clinical psychology, and psychiatry can use the case studies to practice their diagnostic skills. This book may also be of interest to general readers who are interested in the lives of historical and public figures and are curious about how mental health clinicians make diagnoses. In order to avoid any ethical concerns about discussing living people, all of the people described in this book are deceased. The diagnostic impressions provided in this book are tentative rather than definitive. It is almost impossible to know much about a deceased person's mental state at a certain point in their life. Ordinarily, in clinical practice diagnoses are only made after thorough in-person evaluation, observation, and interviewing, sometimes including interviews with friends and family and a review of any relevant medical records. Since interviews are not possible with deceased public figures, the diagnoses offered here are speculative. Even so, there is a great deal of information available about the behavior and personality of many historical figures which supports tentative retrospective diagnosis. Some of the public figures described in this book spoke or wrote openly about their struggles with mental illness, and many of them received diagnoses of their conditions by mental health specialists they consulted.The biographical descriptions in this book are based on published resources, including autobiographies, biographies, articles, medical reports, personal diaries and letters, and video recordings. The biographical profiles summarize the information provided in primary and secondary sources. Sources sometimes have conflicting information regarding details of a person's life, but cross-checking and combining sources can help approximate historical reality. Readers may wish to do further reading and research to develop a fuller understanding of the people described in this book.