**Core Concept**
Lithium is a mood stabilizer commonly used in the treatment of bipolar disorder. Its narrow therapeutic index and potential for toxicity necessitate careful pre-treatment evaluation to minimize risks.

**Why the Correct Answer is Right**
Pre-treatment evaluation for lithium therapy should include assessment of renal function, particularly eGFR (estimated glomerular filtration rate), to prevent lithium toxicity. This is because lithium is primarily excreted by the kidneys, and impaired renal function can lead to lithium accumulation and toxicity. The recommended dose of lithium should be adjusted in patients with renal impairment to avoid adverse effects.

**Why Each Wrong Option is Incorrect**
**Option A:** Electrolyte panel is not the primary focus of pre-treatment evaluation for lithium therapy, although it may be included as part of a comprehensive assessment.
**Option B:** Thyroid function tests are not directly related to lithium therapy, although lithium can affect thyroid function in some patients.
**Option C:** Complete blood count (CBC) is not a specific requirement for lithium therapy, although it may be part of a general medical evaluation.

**Clinical Pearl / High-Yield Fact**
Lithium toxicity can occur even at therapeutic doses in patients with impaired renal function, highlighting the importance of careful dose adjustment and regular monitoring of renal function in patients receiving lithium therapy.

**Correct Answer: C. Complete blood count is not a specific requirement for lithium therapy, although it may be part of a general medical evaluation.