Is there a medicine recommended?

I realize that in addition to suffering from lows and states of severe depression.. i also have states of mania and extreme mania.

Sometimes I feel like I have a greater purpose.. and i'm "better" than alot of people.. sometimes i am focused on so many things at once i lose control of my thoughts. someetimes it feels like my mind is going 1000 mph, and i start to slip slowly after.

the fall down into depression is what really kills me. knowing that i will most likely feel depressed in the next few days.