I'm on a low dose of lithium (400 - 600 mg daily) and haven't gained any weight. I was originally on depakote and I put loads of weight on with that but when I changed to lithium it began to come off. If the weight gain is making you unhappy then have a chat with your Dr to see if there is an alternative, however if it is working well and stabilizing your mood well then you need to weigh up the pros and cons .
What is your current dosage at?
I took Lithium for a second time from December 2009 to January 2010 and gained 15 pounds. My Psychiatrist immediately took me off it. However, I did take Lithium back in July of 2009, and do no recall any weight gain, but it was not continued for one reason or another.
Unfortunatly weigt gain seems to accompany all the physc medications. I've gained too. I am tryin to watch my caloric intake and get some exercise to burn off some fat!
Would love to share happy news but no... I definitely gained weight too. It doesn't help that I eat when I'm really happy or when I'm feeling down.
Ironic isn't it - we take the meds to help stabilize our mood but gain weight and end up feeling depressed!
Take care!