Psychiatric emergencies are encountered throughout the practice of medicine, in many clinical settings. They may range from a patient expressing suicidal thoughts in an outpatient medical visit to an agitated, threatening patient with psychosis who is acutely intoxicated brought to the Emergency Department by ambulance. Decisions regarding admission, discharge, treatment, and referral are time-sensitive in the emergency setting or when acute safety issues are at stake. A broad knowledge of psychiatry and an understanding of potential medical etiologies of behavioral changes are important, as...