Changes in the biochemical integrity and function of the GABA(A)-benzodiazepine receptor (BZR) complex have been implicated in various neurological and psychiatric disorders. The development of specific radioligands for the GABA(A)-BZR have not only contributed to the elucidation of the receptor's biochemical functions, but also provided a means by which these changes are correlated to disease states when studied with the functional imaging modalities of positron emission tomography (PET) and single photon emission computed tomography (SPECT).