Benzodiazepine receptor distribution and diazepam binding in schizophrenia: an exploratory study.
Clinical studies indicate that patients with acute schizophrenia may benefit from benzodiazepine treatment. Therefore we investigated the benzodiazepine receptor distribution and diazepam binding in 20 patients with DSM-III schizophrenia using single photon emission computed tomography (SPECT) with iomazenil as the ligand. In each patient, two SPECT images were obtained: SPECT 1 was obtained 2 h after intravenous injection of 200 MBq I-123-iomazenil. Following SPECT 1, patients received 10 mg diazepam intravenously. Twenty min later, SPECT 2 was started. The highest iomazenil uptake was found in the occipital cortex followed by the frontal and temporal cortices. Baseline iomazenil uptake in the medial frontal cortex was significantly (P < 0.05) correlated with the BPRS total score (r = 0.46). Diazepam injection led to a significant activity decrease in iomazenil binding which was greatest in the frontal 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 frontal cortex may be associated with severity and chronicity of schizophrenia.
Schröder
J
J
Department of Psychiatry, University of Heidelberg, Germany.
Bubeck
B
B
Demisch
S
S
Sauer
H
H
D000328:Adult; D001569:Benzodiazepines / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001665:Binding Sites; D002908:Chronic Disease; D003975:Diazepam / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000627:therapeutic use; D005442:Flumazenil / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D009778:Occipital Lobe / Q000378:metabolism; D011963:Receptors, GABA-A / Q000378:metabolism*; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D013702:Temporal Lobe / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
D011963:Receptors, GABA-A; D001569:Benzodiazepines; D005442:Flumazenil; C063038:iomazenil; D013006:Growth Hormone; D003975:Diazepam; D006854:Hydrocortisone