BENZODIAZEPINE RECEPTOR DISTRIBUTION AND DIAZEPAM-BINDING IN SCHIZOPHRENIA - AN EXPLORATORY-STUDY

Clinical studies indicate that patients with acute schizophrenia may b enefit from benzodiazepine treatment. Therefore we investigated the be nzodiazepine receptor distribution and diazepam binding in 20 patients with DSM-III schizophrenia using single photon emission computed tomo graphy (SPECT) with iomazenil as the ligand. In each patient, two SPEC T images were obtained: SPECT 1 was obtained 2 h after intravenous inj ection of 200 MBq 1-123-iomazenil. Following SPECT 1, patients receive d 10 mg diazepam intravenously. Twenty min later, SPECT 2 was started. The highest iomazenil uptake was found in the occipital cortex follow ed by the frontal and temporal cortices. Baseline iomazenil uptake in the medial frontal cortex was significantly CP < 0.05) correlated with the BPRS total score (r = 0.46). Diazepam injection led to a signific ant activity decrease in iomazenil binding which was greatest in the f rontal regions of interest. With respect to the medial frontal cortex, this effect was significantly (P < 0.05) more pronounced in patients with a remitting than a chronic course of the disorder. These findings suggest that changes of the benzodiazepine receptor system in the fro ntal cortex may be associated with severity and chronicity of schizoph renia. (C) 1997 Elsevier Science Ireland Ltd.