Lamictal is also an anticonvulsant.
Lamictal also doesn't cause weight gain and topamax is an anticonvulsant
Trileptal has a lower incidence of weight gain.
The biggest issue with Lamictal is "the lamictal rash," but this is actually usually either very temporary or the sign of a serious allergic reaction (like it was for me) I got awful purple splotches head to toe that itched and then eventually hurt like bruises. I wish I wasn't allergic because I gained 40 pounds while taking Seroquel over a six month period!
I have BP1 and I take Lamictal. However, it works best on depression, not so well for mania,
Lamictal isn't supposed to cause weight gain, but since I've been on it (5 months) I have gained 30 lbs and gone up two sizes. None of my clothes fit anymore. And the rate of weight gain seems to be increasing, not decreasing.
No change in my other meds, diet, or exercise level.
From reading around the Internet, it seems lamictal is commonly weight-neutral but does cause weight gain in some people.
In my case, enough to cause enough weight-related health risks and self-esteem issues, I am going to go off it.