What is the diagnostic workup for acute psychosis?

From the Guidelines

The workup for acute psychosis should begin with a thorough history and physical examination to distinguish between primary psychiatric disorders and secondary causes, as recommended by the American Psychiatric Association 1. The initial assessment should include a review of psychiatric symptoms and trauma history, an assessment of tobacco use and other substance use, a psychiatric treatment history, an assessment of physical health, and an assessment of psychosocial and cultural factors, as outlined in the APA’s Practice Guidelines for the Psychiatric Evaluation of Adults 1. Initial laboratory tests should include complete blood count, comprehensive metabolic panel, thyroid function tests, urinalysis, urine drug screen, and blood alcohol level. Additional testing may include B12, folate, RPR/VDRL for syphilis, HIV testing, and a pregnancy test for women of childbearing age. Neuroimaging with CT or MRI of the brain is indicated, especially for first-episode psychosis, atypical presentations, or when neurological symptoms are present, as suggested by the ACR Appropriateness Criteria for altered mental status, coma, delirium, and psychosis 1. An electroencephalogram (EEG) should be considered if seizure disorder is suspected. Lumbar puncture may be necessary if CNS infection is a concern. Specialized testing like heavy metal screening, autoimmune panels, or genetic testing may be warranted based on clinical suspicion. While conducting the workup, initial management often includes antipsychotic medication such as risperidone 0.5-2mg or olanzapine 5-10mg daily, with close monitoring for side effects, as recommended by the international clinical practice guidelines for early psychosis 1. Benzodiazepines like lorazepam 0.5-2mg may be added for agitation. This comprehensive approach is essential because psychosis can result from various conditions including primary psychiatric disorders (schizophrenia, bipolar disorder), substance use, medications, metabolic disturbances, infections, neurological conditions, or autoimmune disorders. Identifying the underlying cause guides appropriate treatment and improves outcomes. Some key points to consider in the workup and management of acute psychosis include:

• A thorough history and physical examination to distinguish between primary psychiatric disorders and secondary causes
• Initial laboratory tests to rule out underlying medical conditions
• Neuroimaging with CT or MRI of the brain to evaluate for structural abnormalities
• Consideration of specialized testing such as EEG or lumbar puncture based on clinical suspicion
• Initial management with antipsychotic medication and benzodiazepines as needed
• Close monitoring for side effects and adjustment of treatment as necessary.

From the Research

Acute Psychosis Workup

• The workup for acute psychosis involves a thorough assessment, including a complete medical history, physical examination, and laboratory tests 2, 3.
• Patients with primary psychiatric disorders are likely to have auditory hallucinations, prominent cognitive disorders, and complicated delusions, while those with secondary causes may exhibit cognitive changes, abnormal vital signs, and visual hallucinations 2.
• Illicit drug use is the most common medical cause of acute psychosis, and clinicians should ask about recent head injury or trauma, seizures, cerebrovascular disease, or new or worsening headaches 2.
• A subacute onset of psychosis should raise suspicion for an oncologic cause, and collateral history from family members is helpful in establishing the presentation and course of the illness 2.

Laboratory Tests

• Suggested initial laboratory tests include a complete blood count, metabolic profile, thyroid function tests, urine toxicology, and measurement of parathyroid hormone, calcium, vitamin B12, folate, and niacin 2.
• Testing for human immunodeficiency virus infection and syphilis should also be considered 2.
• A basic metabolic panel can help identify electrolyte abnormalities and kidney disorders, which can impact renal function and acid-base homeostasis 4.

Physical Examination

• The physical examination should include complete neurologic and mental status assessments 2.
• Tachycardia or severe hypertension may indicate drug toxicity or thyrotoxicosis, while fever may suggest encephalitis or porphyria 2.
• Verbal de-escalation and other psychosocial interventions can help create a safe and therapeutic environment for patients with acute psychosis 5.