What are the causes and treatment options for psychosis in patients over 80 years of age?

Causes of Psychosis in Patients Over 80 Years of Age

Secondary medical causes are the most common etiology of new-onset psychosis in patients over 80 years of age, requiring thorough medical evaluation before attributing symptoms to primary psychiatric disorders. 1

Common Causes of Psychosis in the Elderly (80+)

Medical Conditions

• Delirium: Most common cause of acute psychosis in the elderly 1

  • Key features: acute onset, fluctuating course, inattention, altered consciousness
  • Common precipitants: infections (especially UTI, pneumonia), medications, metabolic disturbances

• Neurological Disorders:

  • Dementia with psychotic features (Alzheimer's, Lewy body dementia, vascular dementia)
  • Cerebrovascular disease (strokes, TIAs)
  • Parkinson's disease
  • Brain tumors or metastases
  • Traumatic brain injury

• Endocrine/Metabolic Disorders:

  • Electrolyte imbalances (sodium, calcium, glucose)
  • Thyroid dysfunction
  • B12 or folate deficiency
  • Hepatic or renal failure

• Infections:

  • Urinary tract infections (particularly common in elderly)
  • Pneumonia
  • Sepsis
  • CNS infections (meningitis, encephalitis)

Medication-Related Causes

• Medication side effects or toxicity:
  • Anticholinergic medications
  • Opioid analgesics
  • Benzodiazepines
  • Corticosteroids
  • Dopaminergic medications (for Parkinson's)
  • Polypharmacy interactions

Substance-Related Causes

• Alcohol intoxication or withdrawal
• Prescription medication misuse
• Illicit substance use (less common in this age group)

Primary Psychiatric Disorders

• Late-onset schizophrenia (rare as new onset after age 80)
• Delusional disorder
• Mood disorders with psychotic features (depression, bipolar disorder)

Evaluation Approach

1. Rule out delirium first - most common and potentially life-threatening 1

   • Use validated screening tools like Confusion Assessment Method (CAM)
   • Assess for fluctuating course and inattention

2. Medical workup:

   • Complete blood count, comprehensive metabolic panel
   • Urinalysis and urine culture
   • Thyroid function tests
   • B12, folate levels
   • Medication review for potential interactions/toxicity
   • Brain imaging (CT or MRI) to rule out structural causes 1

3. Neuroimaging considerations:

   • CT or MRI is appropriate for new-onset psychosis in elderly patients 1
   • May need to tailor examination for shorter scan times or use motion-reducing sequences 1

Treatment Considerations

1. Address underlying medical causes first

   • Treat infections, correct metabolic abnormalities
   • Adjust or discontinue offending medications

2. For persistent psychotic symptoms requiring medication:

   • WARNING: Antipsychotics carry black box warnings for increased mortality in elderly patients with dementia-related psychosis 2, 3, 4
   • Start with low doses of atypical antipsychotics if needed:
     • Risperidone: Initial dose 0.25 mg daily (maximum 2 mg daily) 1
     • Quetiapine: Initial dose 12.5 mg twice daily 1
     • Olanzapine: Initial dose 2.5 mg daily 1

3. Non-pharmacological approaches:

   • Provide orientation cues and familiar surroundings
   • Ensure adequate sensory input (glasses, hearing aids)
   • Maintain regular sleep-wake cycle
   • Involve family in care planning 1

Important Cautions

• Antipsychotic medications in elderly patients with dementia-related psychosis increase mortality risk (1.6-1.7 times) 2
• Deaths are typically cardiovascular or infectious in nature 2
• Use the lowest effective dose for the shortest duration possible
• Regular monitoring for side effects is essential
• Avoid typical antipsychotics when possible due to higher risk of extrapyramidal symptoms 1, 5

Remember that new-onset psychosis in patients over 80 is a medical emergency until proven otherwise, and thorough evaluation for underlying causes should precede any psychiatric diagnosis or treatment.