After reading various studies on Anxiety disorders, Bipolar and this study on Depersonalization, I'm surprised to see the correlation between hyperactivity in the occipital (spatial), cingulate and limbic systems in each of these illnesses.
Another interesting finding is that low GABA levels appear to be partly responsible for anxiety conditions such as GAD and panic disorder
. Lamictal, which is thought to increase the levels of GABA in the brain is used to treat Bipolar as a mood stabilizer, Anxiety disorders for its inhibitory effects in the over excited limbic system, and DP/DR (see Mt Sinai research) in some unknown magical way (that I haven't yet read about).
I'm unsure what the implications of this may be, but the relationships and thus the treatments are certainly interesting to ponder.