Emergency psychiatric evaluation is a dynamic process requiring familiarity with a variety of psychiatric syndromes and medical and neurologic issues that mimic and overlap with psychiatric illness. In many areas, emergency medicine physicians and non-psychiatric clinicians are called upon to evaluate and manage psychiatric illness in the emergency or urgent-care setting, or patients may be boarded in an emergency department awaiting disposition. This book uses a case-based teaching format to illustrate principles of diagnosis, evaluation, and treatment across a broad spectrum of phenomena encountered by clinicians in the emergency setting. Chapters cover the basic diagnostic categories of mood, anxiety, trauma-related, personality and psychotic disorders, with focus on risk-assessment and initial treatment recommendations. Additional chapters focus on special populations, including children and adolescents, geriatric patients, patients with developmental disabilities, and patients who are homeless or do not speak English. Medical and neurologic syndromes that mimic psychiatric pathology are discussed, as well as somatic symptom disorders, focusing on the role of consultants to the medical emergency department. Therapeutic relationships in the ED setting are discussed from a psychodynamic perspective, including how clinicians can avoid blind spots and provide a therapeutic environment by being more aware of their own reactions to patients. Also discussed are the use of short-term crisis intervention treatment and community-based mobile crisis teams for managing complex cases and the ethical, legal, and forensic issues encountered in the emergency setting. The case descriptions are followed by discussions and literature review and highlighted by clinical pearls for the ED setting.