Thought Disorders

Background and Importance

Patients with a history of mental disorders have a higher rate of emergency department (ED) visits than the general population. Patients with at least one primary psychiatric visit to an ED are four times more likely to become frequent ED users compared to patients with none, and the severity of mental illness correlates with the frequency of ED utilization. The rate of ED visits for patients with mental disorders has increased substantially over the last several years for both adults and children. Schizophrenia is among the top 10 most disabling and economically catastrophic medical disorders as ranked by the World Health Organization, and the global burden of disease continues to increase, affecting almost 1% of the world’s population. Slightly more men than women are affected and at a younger age. The modal age of onset is between 18 and 25 years for men and between 25 and 35 years for women.

Groups at high risk for developing schizophrenia include migrants, urban dwellers, people born in late winter to early spring, and those with advanced paternal age at conception. The mortality rate for patients with schizophrenia is 2.5 times that of the general population and continues to grow, especially in populations with low socioeconomic status. Patients diagnosed with schizophrenia have a mean life expectancy almost 15 years shorter than the general population and a 5% to 10% life-time risk of death by suicide. Financial costs associated with schizophrenia are disproportionally high relative to other chronic mental and physical health conditions, reflecting both direct costs of care, and indirect costs of lost productivity, criminal justice involvement, social needs, and homelessness.

Pathophysiology

Although the etiology of schizophrenia is multifactorial, it has a substantial genetic component with approximately 80% of disease expression attributed to genetic factors. In addition to genetic factors, environmental and neurodevelopmental influences increase risk of the disease. Such influences include perinatal stress and hypoxia, poor nutrition, infections, and vitamin D and zinc deficiencies. Newer research is showing that schizophrenia may be detectable at earlier stages of development, prior to the first psychotic episode, which may open the window for earlier interventions.

Alterations in the dopaminergic, serotonergic, cholinergic, glutamatergic, and GABA-ergic pathways have been implicated in the pathophysiology of schizophrenia. Symptoms may be caused by cortical excitatory-inhibitory imbalance and subcortical dopamine dysregulation in the frontal, temporal, and mesostriatal brain regions. Imaging and postmortem studies have revealed disturbed oligodendroglia-related processes, altered gene expression, disturbed myelination, and altered numbers of oligodendrocytes in the brains of patients with schizophrenia. Genetic predisposition, coupled with early neurodevelopmental disturbances during postnatal brain maturation, are thought to trigger the onset of overt schizophrenia.

Patients often present to the ED via family, police, or EMS exhibiting symptoms of disorganized thought and behavior. They may express language, ideas, and behavior found to be inappropriate and disruptive to accepted patterns of social interaction. Whether the issue involves thought content (delusions), hallucinations or thought form (structure of thinking), the clinical impression is that of psychosis (detachment from reality and societal norms). Acutely psychotic patients raise concerns for the safety of themselves, those around them, and those attempting to care for them.

The emergency clinician’s role is to prevent and control violent and disruptive behavior while simultaneously determining if the underlying etiology of the psychosis is functional versus organic in nature. Functional causes include schizophrenia and schizophrenia-like illness, mania, and mood disorder–associated psychosis. Organic causes can mimic a functional psychosis. Medication effects, substance abuse, and certain medical disorders must be excluded before symptoms of psychosis can be attributed to an underlying psychiatric illness.

Medical Disorders

Numerous acute and chronic medical conditions can precipitate thought disorders and mimic acute psychosis ( Box 96.1 ). Patients with underlying psychiatric diseases may develop medical conditions that can exacerbate behavioral symptoms and cloud the distinction between psychiatric and organic brain disease.