I am 19 yrs and doctor says I have this manic problem. He has advised Lithium 900 mg daily to me. How long will I have to take it. Another doctor mentioned that I don't need this medicine. He said that I am not manic but I have not learnt to control my mind when I am attracted to anything and when somebody tells me to do something or refrain from doing something I get angry.

What are the side effects and how long witll I have to take it?

Somebody advise. Please