Zopiclone
Zopiclone was developed and first introduced in 1986 by Rhône-Poulenc S.A., now part of Sanofi-Aventis, the main worldwide manufacturer. Initially, it was promoted as an improvement on benzodiazepines, but a recent meta-analysis found it was no better than benzodiazepines in any of the aspects assessed. On April 4, 2005, the U.S. Drug Enforcement Administration listed zopiclone under schedule IV, due to evidence that the drug has addictive properties similar to benzodiazepines.
Zopiclone
Similarly to other sedative hypnotic drugs, zopiclone causes a decrease in the core body temperature and is effective in decreasing sleep latency. It causes similar alterations on EEG readings and sleep architecture as benzodiazepines and causes disturbances in sleep architecture on withdrawal as part of its rebound effect. Zopiclone reduces both delta waves and the number of high-amplitude delta waves whilst increasing low-amplitude waves. Zopiclone reduces the total amount of time spent in REM sleep as well as delaying its onset. Cognitive behavioral therapy has been found to be superior to zopiclone in the treatment of insomnia and has been found to have lasting effects on sleep quality for at least a year after therapy.