Hospital emergency departments (EDs) were initially used to provide immediate care for patients experiencing acute medical conditions or trauma. Their role expanded to provide more extensive management of people with other types of conditions that require immediate care, including people experiencing psychiatric emergencies. Now, EDs are experiencing increased use by people who do not have a primary care physician and use EDs for routine medical care, causing stress on available healthcare resources.

The misuse of emergency services by patients who do not have primary care physicians and use the ED for routine office visits is a continuing problem in the United States and can contribute to ED crowding. According to an analysis by the Centers for Disease Control and Prevention (CDC), the foundation of the overcrowding problem is that the demographics of the U.S. population have changed over time (e.g., a greater number of older Americans, higher incidence of obesity and diabetes) and there are fewer EDs [76,84].

There are many myths regarding ED usage. It is often asserted that most visits to EDs are for non-urgent conditions, but the reality is much different. Based on 2020 CDC National Hospital Ambulatory Medical Care Survey data, 12% of adult and pediatric ED visits nationwide were classified as immediate or emergent, 51.3% as urgent or semi-urgent, and only 2.5% were classified as nonurgent [4]. It is also often reported that Medicaid patients or the uninsured are using EDs as primary care; however, in 2015, the number of adult visits classified as emergent, for example, was higher for privately insured (7.9%) than publicly insured (6.9%) and uninsured (4.4%) patients [4]. The prevailing belief is that poor, uninsured/publicly insured individuals are the problem, when in fact there has been a disproportionate increase in ED use as primary care among privately insured individuals [75,76].

Thorough medical evaluation is clearly indicated for patients with psychiatric emergencies, although the feasibility and extent of screening may differ. The American College of Emergency Physicians (ACEP) has developed policies that address the diagnosis and management of adult psychiatric patients in the ED [5]. There are three elements of the initial assessment of a psychiatric patient in an emergency setting [5,79]:

Patients with suggestive histories, abnormal vital signs, and/or abnormal physical examinations should be cleared of medical illnesses during their evaluation [5]. This generally requires more intensive diagnosis utilizing laboratory and radiologic screening. Several groups have been identified as necessitating further medical evaluation if presenting with psychiatric symptoms, including the elderly, those with substance abuse problems, those with pre-existing or new medical complaints, and those of lower socioeconomic status [6,7]. In addition, patients without a prior psychiatric history should be carefully evaluated for possible physiologic causes of the behavioral changes [6].

Although some studies have indicated the use of laboratory and radiologic evaluation of all patients presenting with psychiatric disturbances in the ED, evidence does not support these interventions for most patients [5]. For alert, cooperative patients with no signs of physical distress whose primary complaint is psychiatric, the ACEP has recommended that diagnostic evaluation be directed by the history and physical examination. Routine laboratory testing is not necessary, because it usually does not change the management or disposition of the patient [5]. However, there are several life-threatening medical conditions that may precipitate a psychotic emergency, including central nervous system or systemic infection, collagen vascular disease, drug overdose or intoxication, head trauma, hypertensive crisis, hypoglycemia, hypoxemia, sedative-hypnotic agent withdrawal, and thyrotoxicosis [8,10]. If the cause of psychosis is unclear, these etiologies should be investigated.

The Classification of Violence Risk (COVR) program, developed by researchers involved with the MacArthur Violence Risk Assessment Study, is software designed to allow clinicians to assess adult patients' risk for violent behavior based on approximately "40 individualized questions, generated by computer algorithms in response to answers to previous questions" [12]. The COVR analyzes 106 variables, which the publisher contends may be ascertained from a chart review and a 10-minute interview with the patient [12].

In addition to chest pain, several other seemingly medical conditions may be linked to psychiatric issues. Asthma attacks certainly have a physical component, but they are also exacerbated by psychological issues, particularly anxiety and fear. Intoxication can be a complicated and potentially dangerous condition that involves self-medication for an untreated or poorly controlled psychiatric disorder. Hopelessness has been found to be a feature in irritable bowel syndrome [16]. It is important to recognize that time constraints may lead professionals to depend on experience when the time to reflect on and investigate other possibilities is not available.

Imminent danger is characterized by a patient describing or manifesting self-destructive behavior that shows a reasonable probability of happening in the immediate hours rather than days, weeks, or months later. Subjectivity comes into play with each professional's interpretation of the patient's statements. The time period for imminent danger may be modified depending on the patient's suicide plan.

There are several levels to suicidal behavior (Table 2). The first level is suicidal ideation. People experiencing personal or financial duress commonly have passing thoughts about "not waking up," "just leaving the mess," or other fleeting thoughts of death. Suicidal ideation, though, is a much more significant pattern of thinking. Instead of transient thoughts when distressed or fatigued, an individual with suicidal ideation experiences frequent and specific thoughts about dying and possible plans of action. No longer is the thought about "not waking up;" it is about how to accomplish that end and either insulate family or friends or blame them for the suicidal decision. At the point of suicidal ideation, the person may not have a firm plan for suicide but instead thinks about it when driving, cutting vegetables with a knife, or engaging in a potentially dangerous activity.

In various studies, researchers have found that 4% of pediatric patients and up to 9% of all patients seeking medical treatment at EDs for nonpsychiatric reasons experienced suicidal ideation, suicide attempt, or self-harm; another 2% of patients had definite suicide plans [19,82,83]. Among those experiencing suicidal ideation or plans, 97% had depression, anxiety, or substance abuse problems. Thus, there may be a psychiatric emergency among people who do not initially present with psychiatric complaints. Because the reason for seeking treatment at an ED may not be psychiatric, it can be easy to overlook the risk of imminent danger.

Hallucinogenic drugs alter the user's perception of reality, mimicking psychosis. The resulting behavior may be dangerous to the user as well as those around the user. Examples of these substances are d-lysergic acid diethylamide (LSD), phencyclidine (PCP), peyote, and hallucinogenic mushrooms. Patients under the influence of hallucinogens often experience periods of anxiety, during which aggressive behavior toward others may be seen, or depression, during which suicide is a serious risk. Paranoia is present along with impaired judgment. Hallucinogenic drugs produce ideas of reference, often influenced by mood prior to ingestion of the substance, in which the user reads personal messages in common events. For example, a song on the radio may be perceived as a special message. Because this is perceived as real, individuals may react protectively or follow orders from an auditory hallucination.

Dementia, delirium, and amnestic disorders are included under the broader category of cognitive disorders. These disorders are based on medical, neurologic, or biochemical factors, generally organic in nature, that adversely affect brain functioning. Delirium and dementia are the primary psychiatric emergencies in this category. Patients experiencing acute or active phases of delirium or dementia require immediate medical care. As such, patients with these disorders are often assessed in EDs. Behavioral manifestations include disorientation, hallucinations, illusions, delusions, and personality changes. A normally mild-mannered person may become quite aggressive and assaultive.

Patients suffering from delirium or dementia cannot participate in healthcare decisions while actively impaired by their illness. In an emergency, family and knowledgeable friends can be valuable sources of information about the patient's health. However, the Health Insurance Portability and Accountability Act (HIPAA) regulations may complicate acquiring helpful information, as discussion of the patient's condition with other individuals may be restricted or impossible.

Major depressive disorder can manifest either as a single episode or a recurring condition. Severity can range from mild to severe, and other factors, including postpartum depression and psychosis, may be present. At least five of the symptoms of this disorder (e.g., depressed mood, loss of pleasure or interest in activities, significant change in weight, sleep disturbance, psychomotor symptoms, fatigue, feeling of worthlessness or inappropriate guilt, diminished ability to think or concentrate, suicidal ideation) must be present nearly every day for at least two weeks for the diagnosis to be made [26]. Psychiatric emergencies with major depressive disorder are the result of the unremitting nature of the symptoms and the intensity with which they are felt. If treatment has either not worked or has not been undertaken for sufficient time, patients with major depressive disorder may become despondent and suicidal, as continuing life is perceived as too painful. Some become extremely withdrawn and experience catatonia, becoming so unresponsive to events around them that they stop eating and begin suffering the physical changes of malnutrition. This is more likely to happen when the person lives alone and does not see others on a frequent basis. Worried family and friends can be the reason that this person is brought to the ED or other professional setting.

Bipolar disorder accounts for approximately 18% of all psychiatric emergencies [32]. It typically appears in the late teens or early 20s and affects men and women equally [33]. The disorder is characterized by manic phases of extreme activity, poor judgment, and loss of contact with reality, and depressive phases, in which the patient becomes depressed, lethargic, and possibly suicidal. Bipolar disorder is categorized as bipolar I or bipolar II disorder.

PTSD secondary to deployment to a military conflict or war is another consideration when assessing patients, particularly due to the military operations in Afghanistan and Iraq. Individuals who have served in a war may develop PTSD due to several unique factors, including exposure to severe combat; having personally killed enemy combatants and, possibly, innocent bystanders; exposure to unpredictable, life-threatening attacks; postcombat exposure to the consequences of combat; exposure to the sights, sounds, and smells of dying men and women; and observation of refugees, devastated communities, and homes destroyed by combat [40]. Certain factors have been identified in veterans of the current conflicts that indicate a greater risk for development of PTSD, including [40,41,42]:

Researchers have found that anxiety is one of the intense affective states associated with suicide ideation and that social phobia, specifically, is associated with suicide attempts [45]. Anxiety disorders have the highest prevalence of all psychiatric disorders. Although suicidal behavior is less likely to occur in patients with anxiety disorders than in patients with other psychiatric disorders, patients with anxiety disorders can be at risk for suicidal behavior, especially when comorbid conditions are present. Professionals providing treatment to anxious patients should assess the degree of suicidality present.

Cluster C personality disorders, which include dependent, obsessive-compulsive, and avoidant individuals, share anxiety as a symptom. Among patients with these disorders, the risk for suicide or harmful behavior usually emerges at the end of a chronic and painful mental illness. Dependent individuals seek the acceptance and approval of others; they will go to great lengths to avoid contradicting someone if they think it would make them angry or unhappy. When an emergency develops, it is because the cluster C personality is finally tired of being dependent on others. It is this sense of hopelessness that may ultimately lead to suicidal behavior.

Personality disorders are not usually the primary reason for seeking emergency treatment. They are, however, an underlying factor behind seeking help in some cases. For example, an overdose may be the reason for going to the ED and the primary focus of treatment; but, borderline personality disorder may be the psychological cause of the overdose. The presence of personality disorders reportedly increases the clinical severity of patients with panic disorder and suicidal behavior [38]. Of all of the personality disorders, paranoid and borderline types are associated with the greatest risk for suicidal behavior. Although treatment of personality disorders is not necessary during emergency or crisis intervention, the diagnosis will help guide treatment and discharge planning. Consequently, the focus in the ED and crisis intervention should include an assessment of imminent danger, whether directed toward self or others. Treating the personality disorder will require long-term therapy by a nonemergency mental health professional.

It has been suggested that improper diagnosis and treatment for mental health issues in the pediatric population, in which approximately 20% suffer from a major psychiatric illness with at least some impairment, has precipitated the increase in emergency services utilization [48,49]. This is particularly true in patients with public insurance, who typically have limited access to mental health services and fewer treatment options [50]. Additionally, there has been a reduction in the number of inpatient beds available at state psychiatric hospitals, where less than half are allocated for acute care, while at the same time funding for outpatient mental health services has not increased to offset the losses [67]. Of pediatric ED visits for psychiatric illnesses, approximately 70% are made by adolescents, and more than 66% of these are classified as urgent [50]. For children and adolescents, the first symptoms of psychiatric illness may result in presentation to the ED, making accurate assessment and referral vital.

As with adult patients, the primary factor in assessing a pediatric patient for psychiatric emergency is determination of imminent danger. A classification system exists to measure risk for harm or other adverse events among pediatric patients [51]. According to this system, patients who exhibit suicidal or homicidal behaviors (actions that are potentially life-threatening) are considered class I. Class II designates patients who are in a "heightened state of disturbance" and require immediate assistance (e.g., rape victims) [51]. Serious but not life-threatening conditions, such as verbal threats of violence, are categorized as class III. Patients with class III conditions should be treated as soon as possible, but not necessarily immediately. Class IV refers to conditions or situations that require attention, but are not considered psychiatric emergencies, including misuse of emergency services or lack of a mental health provider. Classification based on this metric allows healthcare professionals to quickly assess the patient and determine the level of intervention that is warranted. Triage tools (e.g., the Mental Health Triage Scale, Emergency Severity Index, Ask Suicide Screening Questions [ASQ]) that may be incorporated into practice also have been developed based on this system [48,88,89]. All classifications require action, whether it is immediate psychiatric intervention or referral to the appropriate resource. This tool may also be helpful for social work, general health, and allied professionals who are attempting to determine if emergent treatment is indicated.

Suicide is the second leading cause of death in the United States among persons 10 to 24 years of age, accounting for 19.7% of deaths [81]. In the 12 months prior to the 2019 Youth Behavior Risk Survey, 18.8% of high school students seriously considered suicide and 8.9% had ever attempted suicide [54]. Suicidal ideation and attempt among high school students are much higher in girls (24.1% and 11.0%, respectively) than in boys (13.3% and 6.6%, respectively). Overall, planning and attempting suicide peaks for girls during the 10th grade and boys during the 12th grade. Suicide ideation and attempt among girls increased significantly between 2017 and 2019 [54]. Psychosocial factors that have been identified as heightening the risk for suicidal behavior in children and adolescents include [55]:

In many cases, agitation is the most treatable manifestation of a psychiatric emergency. Furthermore, treatment of agitation and/or aggression can facilitate the opportunity for a more thorough analysis and diagnosis. Agitated patients should be thoroughly examined for both physical and psychological causes for the agitation. Organic conditions that may cause agitation range from infections, such as urinary tract infections in the elderly or HIV, to substance abuse [57,58]. Many of these patients will require pharmacologic intervention to calm them quickly and effectively. The recommendation is to start with a low dose of the medication and slowly increase the amount if the required benefit is not achieved.

For the acutely agitated, undifferentiated patient in the ED, benzodiazepines (e.g., lorazepam or midazolam) or first-generation antipsychotics (e.g., haloperidol) have been suggested as effective therapy for initial drug treatment; ketamine may also be considered [5,79]. Recommended initial therapy consists of combination haloperidol and lorazepam [78]. The addition of benztropine or diphenhydramine may reduce the risk of extrapyramidal symptoms. Second-generation antipsychotics, such as ziprasidone and olanzapine, may also be used for initial drug treatment and have fewer short term side effects than haloperidol [59,91]. Agitated but cooperative patients may be treated orally with olanzapine, sublingual asenapine, or a combination of lorazepam and risperidone [79,91]. For the patient with known psychiatric illness for which antipsychotics are indicated, the ACEP has recommended treatment with an antipsychotic (typical or atypical) as effective monotherapy both for management of agitation and initial drug therapy. In 2022, the U.S. Food and Drug Administration (FDA) approved orally dissolving sublingual dexmedetomidine for agitation in patients with schizophrenia or bipolar disorder, and this may be an option for cooperative patients [92].

For the acutely agitated, undifferentiated patient in the ED, benzodiazepines (e.g., lorazepam or midazolam) or first-generation antipsychotics (e.g., haloperidol) have been suggested as effective therapy for initial drug treatment; ketamine may also be considered [5,79]. Recommended initial therapy consists of combination haloperidol and lorazepam [78]. The addition of benztropine or diphenhydramine may reduce the risk of extrapyramidal symptoms. Second-generation antipsychotics, such as ziprasidone and olanzapine, may also be used for initial drug treatment and have fewer short term side effects than haloperidol [59,91]. Agitated but cooperative patients may be treated orally with olanzapine, sublingual asenapine, or a combination of lorazepam and risperidone [79,91]. For the patient with known psychiatric illness for which antipsychotics are indicated, the ACEP has recommended treatment with an antipsychotic (typical or atypical) as effective monotherapy both for management of agitation and initial drug therapy. In 2022, the U.S. Food and Drug Administration (FDA) approved orally dissolving sublingual dexmedetomidine for agitation in patients with schizophrenia or bipolar disorder, and this may be an option for cooperative patients [92].

Delirium and dementia are considered organic conditions, meaning that these conditions generally stem from biologic and/or physiologic causes. Patients with either disorder will require follow-up care. Because these patients can become agitated and combative, it is important to administer a fast-acting sedative. Perphenazine and haloperidol may be used to treat agitated individuals, including children and the elderly [61]. Examples of medications used in the treatment of patients with dementia are donepezil and rivastigmine [61].

As discussed, each state or commonwealth has its own laws pertaining to involuntary hospitalization. Healthcare professionals working with and around psychiatric patients should know the applicable laws or have quick access to that information. Usually, the signatory officer for an order of involuntary hospitalization is a physician or clinical psychologist. The signatory officer should interview the patient and, exercising professional opinion, determine that imminent danger is present and hospitalization is necessary to protect the patient from self-harm. Some states or commonwealths require two signatures. One signature initiates the order to hospitalize the patient, and the other is from the physician at the receiving hospital. Of course, both must agree that imminent danger is present.

Individual practices without an administrative staff or other professionals working in the office are at particular risk in the case of a psychiatric emergency. Again, a locked door that separates the therapy offices from the waiting room and a safe exit from the offices should be installed. Some may invest in a video camera system to monitor who enters the waiting room and what is occurring. Practitioners should decide how to best protect themselves and any patients with them if an emergency occurs.

The Tarasoff Rule requires mental health professionals to: notify law enforcement when they become aware of a threat against someone else; inform the identified target; and provide both law enforcement and the target with the name of the threatening person. It has been recommended that professionals seek legal counsel regarding the requirements in specific states about notifying others of a patient's threat.