This volume is to examine the phenomena of non-disclosure in its wide ranging forms, study its properties, and to deepen the capacity of a mental health professional --as well as all clinicians who provide mental health counseling -- to detect and engage it across a range of clinical settings. Unengaged, sustained DNDD represents an impasse that is destructive to a clinician’s capacity to both understand and treat a patient. Successfully engaged, on the other hand, DNDD offers a unique perspective on in individuals anxieties, presuppositions, and mental functioning. A clinician who is both aware that a patient is withholding information, and comfortable with that awareness, may approach the patient material while listening for both indications of non-disclosed material and—critically—a growing awareness of psychopathology or other motivational forces driving non-disclosure. Written by experts in this area from both adult and child psychiatric specialties, this book is the first to address the issue of DNDD and present clinical pearls for addressing it. This text is a valuable resource for psychiatrists, psychologists, addiction medicine specialists, family physicians, and a wide array of clinicians treating patients who may struggle with disclosure and integrity.