Case Presentation: A 32-year-old Caucasian man is brought to the Emergency Department by EMS after being found hiding naked in a tunnel of a nearby playground. EMS reports he would not let anyone touch him en route. During your interview, the man stops tells you he shed his clothes because the FBI had put a tracer in the fabric. He is very fidgety and quickly becomes irritated when a nurse attempts to start an IV. On physical exam you note slight tremors, dilated pupils, and tachycardia.

By combining the 2010 census populations of California, Washington state, Oregon, Hawaii, and Alaska, you approximate how many adult patients with psychiatric or behavioral emergencies accounted for emergency department visits between 1992 and 2001 in the United States: 53 million. Two decades later, that number just keeps climbing. In North Carolina alone, from 2008-2010, the annual number of emergency department visits for mental health-related complaints increased by 17.7%.

Psychosis has been defined within the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) as requiring the presence of hallucinations (without insight into their pathologic nature), delusions, or both hallucinations without insight and delusions. In the cause of the psychosis, however, lies one of the many nuances of medicine. When initially evaluating a psychotic patient, the starting diagnostic differential is extensive. An episode of psychosis may be due to a medical condition (most commonly) such as a vitamin or nutritional deficiency, central nervous system tumor, or endocrine abnormality, substance or medication induced, delirium or dementia, mood disorder induced, or a true psychosis including such disorders as brief psychotic disorder or a disorder within the schizophrenia spectrum. All of these can be divided into primary causes (or “true” psychiatric disorders) or secondary causes (the “everything else” category). As a physician, understanding the potential underlying causes of a psychosis can lead to quicker diagnoses and more effective and efficient treatment for the patient.

The prevalence of psychosis in the Emergency Department ranges between 6%-25% based on reported prevalence of substance-induced psychosis, post-partum psychoses, and true psychotic disorders such as disorders on the schizophrenia spectrum. In some hospitals, the substance-induced psychosis rates are as high as 20% of all emergency department presentations. Illicit drug users show high prevalence of co-occurrence of mainly independent mood and anxiety psychiatric disorders which can, in turn, increase the likelihood of experiencing an episode of superimposed psychosis during their lifetime. Given this high prevalence, it is important to review the important substances and medications that are the most frequent causes of this psychosis.

Alcohol – While alcohol intoxication is not typically associated with psychosis, moderate to severe withdrawal can present with visual and tactile hallucinations – better known as Delirium Tremens. Delirium Tremens occurs in approximately 5% of alcoholics5 and is associated with a high mortality rate if not adequately identified and treated. Additionally, long term effects of alcohol on the brain lead to syndromes such as Wernicke encephalopathy (acute, reversible depletion of intracellular thiamine) and Korsakoff psychosis/dementia (focal acidosis and cell death due to unresolved depletion of thiamine over time leading to irreversible damage to short term memory). Although both disorders are well described and frequently reviewed in medical education, acute psychosis has been reported as a result of Wernicke encephalopathy in unique circumstances such as post-gastric bypass surgery.  

Hallucinogens – By definition, hallucinogens cause distortion, illusion and frank hallucinations. These hallucinations and distortions can be associated with panic, paranoia and delusional states. Approximately 7% of college students try marijuana at some point during their college career. In one study of those that reported trying marijuana, approximately 15% reported going to or considering going to the emergency department. While rare, psychotic symptoms present as a result of cannabis intoxication in approximately 1% of users. In addition to the short-term consequences, recent reports show increased risk of persistent cognitive defects and schizophrenia-like psychoses as a result of long-term cannabis use. One Danish study goes so far as to suggest up to 44% of patients diagnosed with cannabis-induced psychoses later develop a schizophrenia-spectrum disorder.

Dissociative drugs – Phencyclidine (PCP), and its cousin Ketamine, cause dissociative and delusional symptoms which often lead to the characteristic violent behavior of intoxication. These symptoms, in additional to the disordered speech and disorientation that accompanies PCP intoxication, have been noted to mirror the positive and negative symptoms, as well as the cognitive defects of schizophrenia. It has been suggested that continuing use of PCP after intoxication with psychotic features is associated with higher incidence of psychosis with repeated use.

Steroids – After Cortisone’s introduction in the early 1940s, first reports of psychiatric side effects began to emerge in the 1950s, .  Acute onset psychosis associated with corticosteroids commonly declares itself within the first week of treatment but can occur at any time. Prior psychiatric diagnoses have shown to be a predicting factor in those who develop steroid-induced psychotic symptoms. One study showed as high as 50% of patients with posttraumatic stress disorder had worsening of depressive aspects after corticosteroid use. Other evidence suggests a rate of 20-40% incidence of psychiatric features presenting with a mood disorder. Additionally, corticosteroid use was noted in many patients who presented with bipolar mood disorder and it has been suggested that the corticosteroid treatments activate the underlying mood disorder as later non-steroid induced episodes occurred.  

Amphetamines – Most commonly seen with methamphetamines, temporary paranoid delusional states can be achieved after prolonged use; these may last weeks to years. Long term amphetamine use can lead to alterations of brain structure and function including concentration, memory, and sometimes psychotic symptoms. When evaluated over a lifetime, prevalence of substance-induced psychosis occurs in as high as 42% of cases. Methamphetamine psychosis can very closely resemble that of schizophrenia with an inability to determine if the auditory hallucinations are real.

Inhalants – The most commonly abused substance for school-aged children is the average household inhalant. In 2005, 72% of new volatile substance abusers were younger than 18 years old with a mean age of 16 years. Inhalants provide a quick-onset, short-duration high with minimal hangover or withdrawal symptoms. The most common symptoms associated with inhalant abuse include dizziness, diplopia, ataxic gait, and slurred speech. Visual hallucinations can occur with prolonged use and may be the symptom that brings these patients to the emergency department. Physical exam findings may also include mucous membrane involvement or irritation. Prolonged exposure to inhalants can lead to a demyelination of neurons leading to muscle weakness, tremor, dementia/memory loss, and mood changes. Diligent history taking is vital as a detailed substance use history from the patient may be one of the only indicators that suggest prolonged inhalant use.

Initial management of acute psychosis relies primarily on the presenting level of agitation. A review of treatment by Hillard in 1998 offered a succinct algorithm for the treatment of acutely psychotic patients that has remained applicable. As patient and provider safety are top priorities, Hillard first proposes verbal de-escalation of the patient. If this is unsuccessful, physical restraints may be utilized to allow for a thorough physical exam as cause of psychosis will ultimately determine treatment and disposition. If the patient continues to be agitated/hostile, a history of psychosis or use of antipsychotic medication should be considered. History directs the provider to consider use of antipsychotics prior to the use of benzodiazepines. If no history of psychosis exists, and the patient is not elderly, brain damaged, intoxicated with sedative hypnotics or has a known allergy to benzodiazepines – benzodiazepines may be used for sedation. If any of the previously mentioned conditions exist, the algorithm directs the provider to consider antipsychotics as the first line treatment.

Psychosis presents in many forms and can be the result of many causes. When treating psychosis in the acute setting, patient and provider safety are top priorities, followed closely by adequate evaluation to discover the cause of the psychosis. Many psychiatrists will admit that all too often, the most accurate psychiatric diagnoses are products of extensive history and development as symptoms continue to declare themselves over time. Evidence shows that psychiatric patients often receive less monitoring and care for their medical illnesses, . Our patients deserve our best efforts each day, even if they have one of these potentially developing psychiatric diagnoses.  There are many causes of psychosis – most of which are not a “true” psychiatric illness. As such, it is important to keep in mind other potential causes, including medications and substances of abuse.  

Psychiatric patients aren’t simply “mad people.” According to the Cheshire Cat from Alice in Wonderland, “we’re all mad here. I’m mad. You’re mad.” However, Lewis Carroll also reminds us “the best people usually are.”


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