I have a diagnosis of Bipolar I. I was initially given 900mgs/gabapentin as a second "mood-stabilizer," but..it hit me like a ton of bricks. I don't do well with hydroxyzine and benzodiazepines are out (its a community/public mental health clinic...), so the doctor changed the prescription to 100mgs capsules as needed for anxiety+agitation.

Its not ideal, but I don't think most anti-anxiety drugs are, really. It slows me down enough to get me to simmer down a couple notches. When I'm extra agitated, I take a couple 100mgs capsules with my other as-needed psych drug, low dose risperidone. The combination is sedating enough to lull me to sleep, and then I wake up remarkably...less agitated, less troubled, etc.

so...yeah. I think it depends on the person. I find that when I take it regularly my mood improves a bit. For me, that's better than Klonopin, which I found dampened my mood a bit over time.

Have you tried Lyrica? I think its somewhat controlled (Schedule V, maybe...), but its like uber-neurontin or something. I dunno. the dosing is only 2x daily, vs 3x daily for gabapentin. Just a thought...