Although agitation has been interpreted in many ways, perhaps the most accurate and concise definition is “excessive verbal and/or motor behavior” (1). Agitation can escalate toward aggression, which also can be verbal and/or physical in nature, and violence. Signs of agitation include pacing, irritability, affective lability, verbal outbursts, clenching of the fists or jaw, and threatening or destructive behavior, such as slamming doors and banging walls.

The significance of agitation cannot be overstated. Of psychiatric emergency visits in the United States, it is estimated that anywhere from 20% to 50% might involve patients at risk for agitation (2,3). Up to 10% of patients seen in psychiatric emergency settings might be agitated or violent during their evaluation (4). As many as 1.7 million medical emergency room visits per year may involve agitated patients (3).

At the very least, agitation disrupts a therapeutic milieu. Because agitation can lead to destruction and violence in the absence of intervention, adverse events can affect an institution significantly both in terms of cost and casualties. In a survey of psychiatric emergency services across the country in 1999, it was estimated that agitation led to an average of eight patient-to-staff assaults per facility annually, with some centers reporting more than 25 assaults per year (5). Most of these assaults resulted in staff injury severe enough to miss work (5). One study determined that one third of such assaults were apparently random, whereas two thirds occurred during containment procedures (6). Violence in acute psychiatric care settings correlates positively with a lower staff-to-patient ratio, higher percentage of female staff, and presence of staff without specific training in psychiatry or aggression (7). In contrast, younger staff and staff with greater training and expertise were protective factors against violence (7).

Further confounding the problem of agitation, this behavioral emergency does not arise from a singular illness or mechanism but can manifest through markedly different presentations and diagnoses. Early recognition and intervention are critical in treating the patient and limiting the potential for destruction.

The differential diagnosis of agitation is quite broad, encompassing both psychiatric and medical conditions. Although clinicians most commonly associate agitation with an underlying psychotic disorder, several psychiatric disorders
should be considered in the differential diagnosis. These conditions include mood and anxiety disorders, substance intoxication and withdrawal syndromes, and personality disorders. Common medical disorders, including delirium, dementia, hyperthyroidism, hypoxia, and acidosis, need to be ruled out because early intervention and treatment can limit the morbidity and mortality associated with these conditions.

The emergency psychiatrist faces the challenge of assessing the agitated patient as completely as possible while also containing the patient and limiting the potential for harm. Most violence that is not premeditated is preceded by a prodrome, often 30 to 60 minutes in duration, of increasing psychomotor agitation, such as pacing or loud speech (8).

When possible the interview should be conducted in a quiet, nonstimulating setting. However, given the often busy, loud, and overcrowded settings of psychiatric emergency rooms, this might be much easier said than done. If the interview is conducted in an enclosed space, both patient and psychiatrist should have unobstructed access to the exit so that the patient does not feel boxed in and so that the psychiatrist is able to readily escape should the patient escalate. The psychiatrist must take care to avoid any behavior that could be construed as threatening to the patient, such as touching, staring, or standing over the patient. The interviewer should be empathic and nonconfrontational. Reassuring patients that they are in a safe place, correcting patients’ distortions, and addressing their underlying, irrational fears may be helpful.

The amount of information that can be obtained from interviewing an agitated patient varies dramatically. An interview should always be attempted provided that the psychiatrist does not feel there is imminent danger. Having an additional staff member present during the interview of an agitated patient is a wise safety precaution.

In general, the psychiatrist should attempt to obtain the same information from an agitated patient as from any other patient. This information includes history of present illness, past psychiatric history, history of violence, history of suicidal or self-injurious behavior, past medical history, medications, drug allergies, and substance abuse history. A mental status exam should screen for mood and anxiety disorders, psychotic disorders, and current psychotic symptoms. Screening for suicidal and homicidal ideation is imperative. If the patient allows, a more thorough mental status exam should be conducted, particularly if there is significant concern that the patient may be delirious or suffering from an acute medical condition. If at any point during the interview staff members feel that their own safety is jeopardized, premature termination of the interview is appropriate.

In addition to conducting a thorough interview, diagnostic studies and medical examination can further assist in narrowing the broad differential diagnosis. Abnormal vital signs may be the first clue of an underlying medical disorder or of a substance intoxication or withdrawal syndrome, and should be obtained on all patients. Recognition that symptoms are due to an acute medical condition rather than a psychiatric one might be apparent from just a markedly elevated temperature, pulse, or blood pressure.

Resources available for an adequate medical workup vary significantly depending on the treatment setting. Physicians working in a medical emergency room will commonly have access to laboratory and imaging studies that might not be available to a psychiatrist or social worker in a crisis clinic. Where possible, the following laboratory studies should be obtained: Breathalyzer or blood alcohol level, urine drug screen, complete blood count, blood glucose level or preferably a comprehensive metabolic panel, oxygen saturation, thyroid-stimulating hormone level, and urinalysis. In a patient with no known psychiatric history, a complete workup would also include a computerized tomographic scan of the head and serology testing for syphilis to rule out treatable organic causes for the observed behavioral change.

Various psychiatric, neurologic, and medical illnesses can trigger agitation. The primary sources that would be evaluated in the psychiatric emergency setting are psychoses, affective disorders, substance abuse, dementia, delirium, and akathisia, or a combination of these illnesses. In addition, mental retardation, impulse control disorders, adjustment
disorders, and personality disorders can precipitate aggression. In children and adolescents, conduct disorder should also be considered.

Interestingly, different causes of agitation are postulated to have disparate pathophysiologic mechanisms. Serotonin, dopamine, and gamma-aminobutyric acid (GABA) are all felt to play a role in aggression (9,10). Agitation in psychosis, mania, and substance abuse appears to be linked to an increase in the neurotransmitter dopamine. A decrease in the neurotransmitter GABA is thought to play a role in the agitation associated with dementia, depression, and anxiety. The agitation of delirium may be the result of multiple different causes (11).