To be more clear, Lyrica is not acting on GABA receptors in any way that was proven, a theory exist that it increase the amount of GABA in your brain by making the enzyme that produce it more effective but haven't been proven.
As for its effect, its basically to partially block your body to recieve feedback information from your spinal cord and has some less understood mechanism in the brain, but I suspect that it has some positive impact on dopamine release because it helps with my ADD and create some mood elevation in my case, but its only what I experiance and I use it less than once a week with a rather low dose..