This chapter reviews the most common psychiatric medications used in the emergency setting. It discusses the larger group of psychiatric medications one encounters daily on patients' medication lists. The most commonly prescribed psychiatric medications are the antidepressants, subdivided into four classes: tricyclic antidepressants (TCAs), heterocyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs). Antipsychotics, despite numerous side effects, have revolutionized the treatment of schizophrenia, allowing patients who once had to be hospitalized to live fairly normal lives. Several medications are considered mood stabilizers, also referred to as antimania medications. They include lithium, carbamazapine, valproic acid, and some atypical antipsychotics. Chemical restraint of an agitated patient is perhaps the most common reason psychiatric medications are used in the emergency department. The most common medications used for chemical restraint are haloperidol, droperidol, ziprasidone, olanzipine, lorazepam, and midazolam. The atypical antipsychotics are increasingly being used for acute agitation.

Substance use is highly prevalent among patients presenting to emergency departments (EDs). Substance use complicates differential diagnosis of the ED patient, as substance use can mimic a variety of psychiatric syndromes. Chronic drug and/or alcohol use significantly increases the likelihood that a person will use an ED for medical treatment. The drugs of abuse and intoxication include alcohol, opiates, sedative hypnotics, stimulants, hallucinogens and dissociative agents, inhalants, and cannabinoids. Drug intoxication is commonly involved in ED visits, and patients may present with a variety of medical and psychiatric complaints. Drug intoxication complicates clinical presentation and can lead to prolonged ED length-of-stay, deployment of resources, including the use of restraints in severe intoxication syndromes, and creates a challenge for disposition and treatment.

In malingering and factitious disorder, the patient pretends to be ill or intentionally causes his or her own symptoms. This chapter reviews the diagnosis, assessment, and management of these, often difficult, patients, providing practical advice to the emergency physician. Malingering and factitious disorder are both forms of somatization in which the patient is aware of producing or feigning their symptoms. A sub-category of factitious disorder, Munchausen syndrome, named after the famous 18th century traveling storyteller, Baron von Munchausen, is characterized by patients who travel widely and tell elaborate tales about their illnesses and treatments thus becoming career medical imposters. Both malingering and factitious disorder are diagnoses of exclusion. While recognition is the first step in the psychiatric management of malingering and factitious disorder, this is not easy to do when an unknown patient presents to the emergency department (ED). The chapter summarizes recommendations for the management of these disorders.