3. Thyroid stimulating hormone (TSH) over \>20% above the upper normal limit (participants maintained on thyroid medication must be euthyroid for at least 3 months before Visit 1;
4. Other contraindication to lithium,
5. Patients who have had severe adverse reaction to Lithium;
8. Pregnancy as determined by serum pregnancy test or breastfeeding;
9. History of nonresponse to lithium at doses ≥ 900 mg/d for ≥ 8 weeks;
10. Unwilling to have blood drawn
11. Patients with chronic medical conditions such as diabetes, coronary artery disease, immune diseases, infectious diseases and neurological disorders;
12. Active suicidal ideation with a plan or intent, a suicide attempt within past 6 months or more than 2 suicide attempts within the past 2 years.
