This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
[{'content': 'Drug of choice for bipolar syndrome: \nSelect and explain. \nA. Lithium, B. Imipramine, C. Phenytoin, D. Clozapine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. LithiumLithium is mood stabilizer which is drug of choice for bipolar syndrome. It has narrow therapeutic index. (8-1.2ng/dl). It is known to cause tremor, nephrotoxicity, hypothyroidism and Ebstein anomaly. Other drugs like SSRI, valproate, carbamazepine, lamotrigine can also be given in bipolar disease.', 'role': 'assistant'}]