I took gabapentin as a mood stabilizer about 10 years ago and it didn't do a heck of a lot for my mood. It did help a bit with anxiety, but was pretty useless otherwise. You might be interested to read an article I found about it. The company was sued for illegal marketing. Basically, people did better on placebo than they did on gabapentin.

Here's the link: http://bipolar.about.com/cs/neuronti...ontin_suit.htm