For Over a Hundred Years, research on pathological lying has remained tucked away in case studies, mentioned in some neuroscience articles, alluded to within clinical assessments, or briefly touched on in book chapters and encyclopedias. As a result, pathological lying has been called by different names and characterized in innumerable ways, with no formal definition or diagnosis. Recently, there has been a reemergence of research examining pathological lying, which has helped establish research markers, categorical distinctions, assessment profiles, and clinical parameters. This book synthesizes and unifies historical and contemporary writings and research on pathological lying into a functional and cohesive resource for researchers and clinicians. By offering a succinct, theory-driven, and empirically corroborated account of this disorder, the authors aim to provide clinicians with the tools they need to more accurately identify and effectively treat patients.