What labs should be checked for sudden mood changes?

Laboratory Tests for Sudden Mood Changes

For patients with sudden mood changes, a comprehensive laboratory workup should include thyroid function tests, electrolyte panel, complete blood count, glucose levels, toxicology screen, and vitamin B12 levels to identify potential medical causes that could be contributing to or causing the mood disturbance.

Initial Laboratory Evaluation

When evaluating patients with sudden mood changes, laboratory testing should be guided by clinical presentation rather than performed as an extensive routine battery. Targeted testing based on history and physical examination yields the highest clinical value while minimizing false positives.

Essential Laboratory Tests:

• Thyroid Function Tests (TSH, T3, T4)

  • Hypothyroidism and hyperthyroidism can present with mood disturbances
  • Particularly important in patients with affective disorders 1

• Basic Metabolic Panel

  • Sodium, potassium, calcium, glucose, BUN, creatinine
  • Electrolyte imbalances can cause acute mental status changes 1
  • Hypercalcemia (from hyperparathyroidism) may present with mood symptoms 2

• Complete Blood Count (CBC)

  • Screens for infections, anemias that may affect mood
  • Particularly important in elderly patients 1

• Fasting Glucose

  • Hypoglycemia and hyperglycemia can cause mood alterations
  • Diabetes screening is important in patients with mood disorders 1

• Toxicology Screen (urine and/or serum)

  • Essential to rule out substance-induced mood disorders
  • Particularly important in patients without prior psychiatric history 1

• Vitamin B12 and Folate Levels

  • Deficiencies can present with mood changes, especially in older adults 1

Additional Testing Based on Clinical Presentation

• Liver Function Tests

  • Important for patients with suspected Wilson's disease or other metabolic disorders 2

• Lipid Panel

  • Recommended for patients taking atypical antipsychotics 1

• Inflammatory Markers (ESR, CRP)

  • Consider when autoimmune or inflammatory conditions are suspected 3

• Cortisol Levels

  • When Cushing's syndrome is suspected (weight gain, mood changes) 2

High-Risk Patient Groups Requiring More Extensive Testing

More comprehensive laboratory testing is warranted in:

1. Elderly patients - higher risk of medical conditions presenting with psychiatric symptoms 1
2. Patients with substance abuse history 1
3. Patients without prior psychiatric history presenting with new-onset mood changes 1
4. Patients with comorbid medical complaints 1
5. Patients with lower socioeconomic status - may have undiagnosed medical conditions 1
6. Patients with sudden onset of symptoms - more likely to have medical etiology 2

Common Pitfalls to Avoid

• Assuming all mood changes are primarily psychiatric - Medical conditions like thyroid disorders, Cushing's syndrome, and pancreatic cancer can present initially with mood symptoms 2

• Overlooking substance use - Intoxication and withdrawal can mimic mood disorders; always screen for substances 1, 4

• Missing mixed mood states - Patients may present with both manic and depressive symptoms simultaneously, requiring careful assessment 4

• Neglecting circadian rhythm disruptions - Sleep-wake cycle disturbances can present as mood changes and require specific evaluation 3

• Relying solely on laboratory testing - History remains the most sensitive tool (94% sensitivity) for identifying medical conditions in psychiatric patients 1

Follow-up Monitoring

For patients diagnosed with mood disorders requiring medication:

• Medication-specific monitoring:
  • Lithium: Baseline CBC, thyroid function, renal function, calcium; follow-up every 3-6 months 1
  • Valproate: Baseline liver function, CBC, pregnancy test; periodic monitoring every 3-6 months 1
  • Atypical antipsychotics: Baseline BMI, waist circumference, blood pressure, fasting glucose, lipid panel; follow BMI monthly for 3 months then quarterly; blood pressure, glucose, and lipids after 3 months then yearly 1

Remember that laboratory testing should be targeted based on clinical presentation, with more comprehensive testing reserved for high-risk groups or when the initial evaluation suggests a medical cause for mood changes.