Did some googling about benzos last night and stumbled on a website with these chemistry geeks talking about new developments in anti-anxiety drugs. It appears that drug companies are gearing their R & D towards benzos with what are called "ligands" that will reduce anxiety but have absolutely no effect on sleep. Ligands have some relationship to the analogs that fit on to the basic benzene-diazepine ring of the benzo molecule. These ligands attach to the GABA receptors at various attachment sites. Benzos have traditionally been non-selective so that in the right dose they produce both a reduction in anxiety as well as sleep in many cases. Why on earth would you want a benzo that reduced anxiety but did nothing to help you sleep? The only plausible reason I can come up with is that these new formulations would "supposedly" be non-addictive.