Effects of Zopiclone, a New Anxiolytic-Sedative Drug, on the Frontal Midline Theta Activity in Man

The theta activity which appears on the frontal midline area during performance of mental tasks has been designated as Fmθ. In the present study, a possibility of zopiclone as an anxiolytic was investigated using Fmθ as compared with diazepam. Sixteen male university students were given placebo, diazepam 5 mg, zopiclone 5 mg and 10mg, in a double-blind, cross-over design. EEGs were recorded before and during performance of an arithmetic addition test. This was repeated twice before and 1 hr after the drug administration. Diazepam increased Fmθ markedly but both zopiclone 10mg and placebo slightly and zopiclone 5 mg failed to affect Fmθ. Scores of the state anxiety were reduced most markedly by diazepam and slightly by zopiclone 10 mg but not affected by either zopiclone 5 mg or placebo. The tasks performed were reduced markedly and dose-dependently by zopiclone 5 mg and 10mg, and very slightly by diazepam but slightly increased by placebo. These results suggest that zopiclone possesses rather potent hypnotic effect than anxiolytic, and that Fmθ might be a useful tool to predict the clinical efficacies of anxiolytic drugs in normal humans.

zopiclone

diazepam

抗不安作用

脳波

Fmθ