Psychosis in Medical Conditions

Defining Secondary Psychosis - Medically‑Induced Madness

• Psychosis directly due to a general medical condition's physiological effects.
• DSM-5 Highlights (📌 HPL-ND-NOD):
  • Prominent hallucinations/delusions.
  • Evidence (History, Physical, Labs) of medical cause (HPL).
  • Not during Delirium (ND).
  • Not another mental Disorder (NOD).
• Temporal link: Psychosis onset/worsening tied to medical illness.

⭐ The diagnosis requires evidence that the psychosis is a direct pathophysiological consequence of the medical condition.

Common Medical Causes - Body's Betrayal Brain

📌 NEuro MITES V Mnemonic: (Neurologic, Endocrine, Metabolic, Infectious, Trauma/Toxin, Electrolyte, Systemic/Autoimmune, Vitamin deficiency)

⭐ Anti-NMDA receptor encephalitis: key autoimmune cause; prominent psychosis, esp. young females.

Clinical Clues & Workup - Red Flag Roundup

• Clinical Red Flags (Suspect Medical Cause): 📌 Mnemonic: 'OLDER Vitals'
  • Older age of onset (>40 years).
  • Late onset (new psychosis at an atypical age).
  • Different hallucinations (prominent visual, tactile, olfactory vs. primarily auditory).
  • Erratic course (fluctuating symptoms, lucid intervals).
  • Rapid onset (acute or subacute).
  • Vitals instability (e.g., fever, tachycardia, BP changes) AND/OR Neurological signs (e.g., focal deficits, seizures, ataxia).
  • Clouding of consciousness (key indicator of delirium overlap).
  • Recent medical illness, surgery, or new medication/substance change.

⭐ Visual hallucinations in an adult with new-onset psychosis strongly suggest an underlying medical or substance-induced cause over a primary psychotic disorder.

• Diagnostic Workup Algorithm:

*   **Initial Labs:** CBC, CMP (electrolytes, glucose, renal & liver function), TFTs, urinalysis, urine toxicology.
*   **Further Investigations (guided by clinical suspicion):** Vitamin B12/folate, syphilis serology, HIV test, autoimmune screen (ANA, anti-NMDAR Ab), CSF analysis, EEG, Brain imaging (CT/MRI).

Management Blueprint - Fixing the Fault

• Treat Underlying Medical Condition: Paramount, often curative.
• Symptomatic Management:
  • Antipsychotics (APs): Cautious use. 'Start low, go slow'.
    • Atypical APs (risperidone, olanzapine) preferred: ↓ EPS risk.
    • Monitor: QTc, metabolic effects.
    • Short-term use ideal.
    • ⚠️ Avoid high anticholinergic APs (elderly/delirium).
  • Benzodiazepines (BDZs): For agitation/anxiety, use cautiously (risk: disinhibition, worsening delirium).
• Supportive Care:
  • Safe environment.
  • Reorientation.
  • Family involvement.
• Prognosis: Good if underlying cause treated.

⭐ The primary goal in managing psychosis due to a medical condition is to treat the underlying medical illness; antipsychotics are adjunctive for symptom control.

High‑Yield Points - ⚡ Biggest Takeaways

• Rule out medical/substance causes first in any new-onset psychosis.
• Key triggers: delirium, dementia, endocrine (thyroid), autoimmune (SLE, anti-NMDA), infections (HIV), metabolic, B12 deficiency.
• Temporal link between illness and psychosis is vital for diagnosis.
• Features: often visual hallucinations, fluctuating course, cognitive decline.
• Treat the underlying medical cause primarily; use low-dose antipsychotics cautiously.
• Investigations: EEG, neuroimaging, targeted lab tests are essential.
• Remember iatrogenic psychosis (e.g., steroids, L-dopa).