- Published on
Emergency And Acute Medicine – Psychosis: Medical vs. Psychiatric
Psychosis is a mental derangement characterized by hallucinations, delusions, or grossly disorganized behavior resulting in loss of contact with reality. Its pathophysiology is complex and not fully understood, though excess dopaminergic signaling is thought to contribute. Psychosis can range from mild thought disturbance to severe states such as catatonia. Central nervous system impairment leading to psychosis may arise from neurologic disease, metabolic disturbances, toxins or medications, infections, or primary psychiatric illness. Distinguishing medical from psychiatric causes is critical in emergency care.
Certain features increase suspicion for a primary psychiatric disorder: onset in late adolescence or early adulthood, preserved orientation, and hallucinations incorporated into a structured delusional system. In contrast, features suggesting a medical cause include middle- or late-life onset, acute presentation, fluctuating course, abnormal vital signs, disorientation, distractibility, recent memory loss, substance use history, absence of prior psychiatric or family history, and presence of underlying medical illness. Visual hallucinations in particular are more commonly associated with medical etiologies such as delirium, dementia, migraines, dopaminergic therapy, posterior cerebral infarcts, or narcolepsy.
Medical causes of psychosis span multiple systems. Neurologic conditions include head trauma, tumors, stroke, seizures, hydrocephalus, and neurodegenerative disorders such as Parkinson, Huntington, Alzheimer, Pick, and Wilson disease. Infectious causes include urinary tract infection or pneumonia in the elderly, HIV, neurosyphilis, encephalitis, Lyme neuroborreliosis, and parasitic infections such as cerebral malaria or toxoplasmosis. Metabolic derangements include electrolyte abnormalities, hypoglycemia, hypoxia, porphyria, and withdrawal syndromes. Endocrine disorders (thyroid, parathyroid, adrenal, pituitary), organ failure (renal, hepatic, cardiac), nutritional deficiencies (B12 deficiency, Wernicke–Korsakoff syndrome, pellagra), autoimmune disease (SLE, sarcoidosis), demyelinating disease, and postoperative delirium may also present with psychosis. Intoxicants (alcohol, stimulants, hallucinogens, opioids, cannabis), toxins (carbon monoxide, heavy metals, organophosphates), and numerous medications—including corticosteroids, anticholinergics, sedative–hypnotics, antiparkinsonian agents, antibiotics, cardiac drugs, and over-the-counter sympathomimetics—must be considered. Primary psychiatric causes include schizophrenia spectrum disorders, mood disorders with psychotic features, delusional disorder, stress-related disorders, and postpartum psychosis.
Clinically, psychosis involves impaired reality testing, inappropriate affect, and poor impulse control. Hallucinations are sensory perceptions without external stimuli, while delusions are fixed false beliefs held with certainty and incorrigibility. Thought process abnormalities may include loose associations or disorganization. Affective features such as mania, depression, or catatonia may coexist. History should assess time course (acute vs. chronic), medication adherence, substance use, recent surgery or trauma, systemic symptoms (fever, weight loss), and family history. Collateral information is often essential. Physical examination must include vital signs and a focused neurologic and cognitive assessment, particularly attention and orientation.
A detailed history and exam guide the workup. In patients with known psychiatric illness, benign history, and normal exam, the likelihood of significant laboratory abnormalities is low. First-line laboratory studies often include CBC, electrolytes (including calcium), renal function, glucose, liver function tests, thyroid function tests, B12 and folate levels, urinalysis, and toxicology screening. Second-line tests are guided by suspicion and may include ammonia, HIV testing, fluorescent treponemal antibody absorption (for neurosyphilis), ceruloplasmin (for Wilson disease), heavy metal screening, ESR, CRP, or autoimmune markers. Neuroimaging is indicated when history or examination suggests neurologic disease, or in first-episode psychosis in patients over age 50. CT or MRI may be used; routine imaging without clinical indication has limited value. ECG is recommended before neuroleptic administration to assess QT interval. Lumbar puncture and EEG are not recommended for routine screening but may be appropriate when specific concerns arise.
Management begins with ensuring safety of the patient, staff, and bystanders. Vital signs, oxygen saturation, and serum glucose should be checked promptly. If the patient is uncooperative and dangerous, behavioral control may be necessary. When a medical cause is identified, treatment should target the underlying condition. For behavioral control, haloperidol combined with lorazepam is commonly used and minimally interferes with ongoing medical evaluation. Atypical antipsychotics such as olanzapine or ziprasidone may be administered IM; dissolving oral preparations of olanzapine and risperidone are available. IM lorazepam should not be given concurrently with IM olanzapine due to risk of respiratory depression. QT interval should be assessed before administering neuroleptics.
First-line pharmacologic management often includes haloperidol 2–10 mg IM or IV combined with lorazepam 0.5–2 mg IM or IV. Second-line options include olanzapine 5–10 mg PO/SL/IM, risperidone 1–2 mg PO/SL, quetiapine 25–100 mg PO, or diazepam 5–10 mg IV. In geriatric patients, antipsychotics carry increased mortality risk; lower starting doses are recommended, and benzodiazepines should be used cautiously, particularly in delirium. In pregnancy, first-generation antipsychotics such as haloperidol have the strongest safety data.
Disposition depends on etiology and risk. Patients with medical causes require admission to the appropriate medical service. Patients with primary psychiatric causes may require psychiatric hospitalization if they pose danger to themselves or others, cannot care for themselves, or have severely disorganized thought processes. Laws governing involuntary hospitalization vary by jurisdiction. Discharge is appropriate only when the patient is medically stable, not suicidal or homicidal, able to care for themselves, and capable of medical decision-making, with follow-up arranged within one to two weeks.
A key principle is to maintain high suspicion for organic causes before attributing psychosis solely to psychiatric illness. Collateral history is essential, as psychotic patients may not provide reliable accounts. Careful assessment and systematic evaluation are critical to prevent missing reversible medical causes.
Psychosis is a mental derangement characterized by hallucinations, delusions, or grossly disorganized behavior resulting in loss of contact with reality. Its pathophysiology is complex and not fully understood, though excess dopaminergic signaling is thought to contribute. Psychosis can range from mild thought disturbance to severe states such as catatonia. Central nervous system impairment leading to psychosis may arise from neurologic disease, metabolic disturbances, toxins or medications, infections, or primary psychiatric illness. Distinguishing medical from psychiatric causes is critical in emergency care.
Certain features increase suspicion for a primary psychiatric disorder: onset in late adolescence or early adulthood, preserved orientation, and hallucinations incorporated into a structured delusional system. In contrast, features suggesting a medical cause include middle- or late-life onset, acute presentation, fluctuating course, abnormal vital signs, disorientation, distractibility, recent memory loss, substance use history, absence of prior psychiatric or family history, and presence of underlying medical illness. Visual hallucinations in particular are more commonly associated with medical etiologies such as delirium, dementia, migraines, dopaminergic therapy, posterior cerebral infarcts, or narcolepsy.
Medical causes of psychosis span multiple systems. Neurologic conditions include head trauma, tumors, stroke, seizures, hydrocephalus, and neurodegenerative disorders such as Parkinson, Huntington, Alzheimer, Pick, and Wilson disease. Infectious causes include urinary tract infection or pneumonia in the elderly, HIV, neurosyphilis, encephalitis, Lyme neuroborreliosis, and parasitic infections such as cerebral malaria or toxoplasmosis. Metabolic derangements include electrolyte abnormalities, hypoglycemia, hypoxia, porphyria, and withdrawal syndromes. Endocrine disorders (thyroid, parathyroid, adrenal, pituitary), organ failure (renal, hepatic, cardiac), nutritional deficiencies (B12 deficiency, Wernicke–Korsakoff syndrome, pellagra), autoimmune disease (SLE, sarcoidosis), demyelinating disease, and postoperative delirium may also present with psychosis. Intoxicants (alcohol, stimulants, hallucinogens, opioids, cannabis), toxins (carbon monoxide, heavy metals, organophosphates), and numerous medications—including corticosteroids, anticholinergics, sedative–hypnotics, antiparkinsonian agents, antibiotics, cardiac drugs, and over-the-counter sympathomimetics—must be considered. Primary psychiatric causes include schizophrenia spectrum disorders, mood disorders with psychotic features, delusional disorder, stress-related disorders, and postpartum psychosis.
Clinically, psychosis involves impaired reality testing, inappropriate affect, and poor impulse control. Hallucinations are sensory perceptions without external stimuli, while delusions are fixed false beliefs held with certainty and incorrigibility. Thought process abnormalities may include loose associations or disorganization. Affective features such as mania, depression, or catatonia may coexist. History should assess time course (acute vs. chronic), medication adherence, substance use, recent surgery or trauma, systemic symptoms (fever, weight loss), and family history. Collateral information is often essential. Physical examination must include vital signs and a focused neurologic and cognitive assessment, particularly attention and orientation.
A detailed history and exam guide the workup. In patients with known psychiatric illness, benign history, and normal exam, the likelihood of significant laboratory abnormalities is low. First-line laboratory studies often include CBC, electrolytes (including calcium), renal function, glucose, liver function tests, thyroid function tests, B12 and folate levels, urinalysis, and toxicology screening. Second-line tests are guided by suspicion and may include ammonia, HIV testing, fluorescent treponemal antibody absorption (for neurosyphilis), ceruloplasmin (for Wilson disease), heavy metal screening, ESR, CRP, or autoimmune markers. Neuroimaging is indicated when history or examination suggests neurologic disease, or in first-episode psychosis in patients over age 50. CT or MRI may be used; routine imaging without clinical indication has limited value. ECG is recommended before neuroleptic administration to assess QT interval. Lumbar puncture and EEG are not recommended for routine screening but may be appropriate when specific concerns arise.
Management begins with ensuring safety of the patient, staff, and bystanders. Vital signs, oxygen saturation, and serum glucose should be checked promptly. If the patient is uncooperative and dangerous, behavioral control may be necessary. When a medical cause is identified, treatment should target the underlying condition. For behavioral control, haloperidol combined with lorazepam is commonly used and minimally interferes with ongoing medical evaluation. Atypical antipsychotics such as olanzapine or ziprasidone may be administered IM; dissolving oral preparations of olanzapine and risperidone are available. IM lorazepam should not be given concurrently with IM olanzapine due to risk of respiratory depression. QT interval should be assessed before administering neuroleptics.
First-line pharmacologic management often includes haloperidol 2–10 mg IM or IV combined with lorazepam 0.5–2 mg IM or IV. Second-line options include olanzapine 5–10 mg PO/SL/IM, risperidone 1–2 mg PO/SL, quetiapine 25–100 mg PO, or diazepam 5–10 mg IV. In geriatric patients, antipsychotics carry increased mortality risk; lower starting doses are recommended, and benzodiazepines should be used cautiously, particularly in delirium. In pregnancy, first-generation antipsychotics such as haloperidol have the strongest safety data.
Disposition depends on etiology and risk. Patients with medical causes require admission to the appropriate medical service. Patients with primary psychiatric causes may require psychiatric hospitalization if they pose danger to themselves or others, cannot care for themselves, or have severely disorganized thought processes. Laws governing involuntary hospitalization vary by jurisdiction. Discharge is appropriate only when the patient is medically stable, not suicidal or homicidal, able to care for themselves, and capable of medical decision-making, with follow-up arranged within one to two weeks.
A key principle is to maintain high suspicion for organic causes before attributing psychosis solely to psychiatric illness. Collateral history is essential, as psychotic patients may not provide reliable accounts. Careful assessment and systematic evaluation are critical to prevent missing reversible medical causes.
0 Comments
