INTRODUCTION AND EPIDEMIOLOGY
Psychosis has been defined as a “fundamental derangement of the mind characterized by defective or lost contact with reality.”1 The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition,2 defines psychotic disorders as those that include abnormalities in one or more of five domains: hallucinations, delusions, disorganized or abnormal motor behavior, disorganized thinking, and negative symptoms. The hallmark of these psychoses, schizophrenia, has a worldwide prevalence of 0.5% to 1%3 and affects approximately 2.4 million adults in the United States.4 Schizophrenia is considered one of the leading causes of chronic incapacity.5-7
The assessment of the psychotic patient presenting to the ED can be challenging, because patients may be agitated, combative, uncooperative, or unable to provide any history. The goals of evaluation are multiple. First, minimize any potential harm to the patient and ensure the safety of the ED staff and other patients. In the case of an aggressive or violent patient, this may require the use of verbal de-escalation techniques, physical restraints, or chemical sedation. Second, assess for any coexisting or confounding medical or traumatic conditions. Emergency care providers are gatekeepers to the psychiatric world, because once the patient is funneled into the psychiatric treatment realm, organic conditions may become more difficult to identify and treat. Psychiatric conditions contribute to increased mortality from comorbid medical conditions as compared to the general population.8 In fact, patients with schizophrenia have a life expectancy of approximately 20 years less than that of the general population.9 Finally, aim to optimize the treatment of the patient’s underlying psychiatric illness, either by connection with the appropriate inpatient or outpatient resources or by contacting their psychiatrist.
Both environmental and genetic factors contribute to the schizophrenia spectrum of disorders.10,11 The disorders have been linked to a spectrum of risk alleles, with overlap between the alleles associated with schizophrenia and those associated with other disorders such as autism and bipolar disorder.12 It is thought that dopamine acts as the common final pathway of a wide variety of predisposing factors, either environmental, genetic, or both, that lead to the disease. Other neurotransmitters, such as glutamate and adenosine, may also collaborate with dopamine to give rise to the entire picture of schizophrenia.13,14
Features of psychoses include hallucinations, delusions, disorganized thinking, and negative symptoms.
A hallucination is an “apparent, often strong subjective perception of an external object or event when no such stimulus or situation is present.”2 Although hallucinations may occur in any sensory modality, they are most commonly auditory in schizophrenia and other psychotic disorders. Typically these are experienced as voices distinct from the individual’s own thoughts. Not all hallucinations are considered to be pathologic; they may be a normal part of certain religious and cultural experiences.