Tegretol did not cause weight gain for me.

It calmed me nicely, less anxiety and no ruminations. But it stopped working after 5 months. All the tweaks with dose and other meds did nothing but make things worse. It did, for a time, help with hypomania and anxiety, but when a depressive episode swung around, it was useless. After two years we gave up on it. I was left with a bunch of tooth decay, after being cavity free for 20 odd years. I should add that this was 15 years ago, but I'm pretty sure my memory of my experience is accurate.

But, I did not gain weight with it. This is just my experience with Tegretol.

TL;DR No, I did not gain weight with Tegretol. No, it did not help with depression.