This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Personality Disorders, Subject name: Psychiatry
Lithium most commonly used in: 
Select and explain. 
A. Bipolar disorder, B. Depressive disorder, C. Personality disorder, D. Headache
A: Bipolar disorder
Answer: A: Bipolar disorder 
Explanation: Ans. (a) Bipolar disorderRef.: Harrison 19th ed. / 2717* DOC for prophylaxis of bipolar disorder- Lithium* DOC for acute mania: Lithium* Lithium can also be used in treatment of neutropenia and cluster headache and major depression episodes.* Therapeutic level of lithium: 0.8 - 1.2 mEq/L* Toxicity seen after >1.5 mEq/L* Most common side effect of lithium: Tremor* Lithium is contraindicated in 1st trimester of pregnancy. It can cause congenital heart defect- Ebstein anomaly.