My son just got put on Lithium for his bipolar disorder: What should I know about this medication?

My experience with bi-polar is that it is rare to have one so young be diagnosed with the condition. Lithium, like most all medications for treatment of a mental condition requires a certain amount of time to reach what is called theutic levels - usually about a month or more. Weight gain is a common occurrence although my wife took Lithium for a number of years without that particular side effect, nor did she develop any side effects until after approx. twelve years when she developed hand tremors as an aculative effect of long term use. I suggest you do an on line search of Lithium as well as the other medications your son is taking. I will only add that the drugs your son is on seems excessive.