I've been on 100 mg for 4 years. Although it has worked well as a mood-stabilizer and kept me off drugs and alcohol, I hated the morning brain fog. I tried to taper off too quickly and had horrible side effects - deep depression, head-aches, total loss of energy and of course insomnia. I am now back up to 50 mg after going from 100 to 50 to 25 to zero in a week. I feel I have to go much slower this time. I'll prob do 50 / 25 every other night for a month, then 25 every night for a month, then 25 / zero every night for another month so we are talking very very slow. It was no problem going from 100 to 50 at all. That's why I guess I kept going so rapidly. There's something that happens when you get to those lower doses like it's almost more intense of an effect. I hope that helps! A