text: In the United States, eszopiclone is a schedule IV controlled substance under the Controlled Substances Act. Use of eszopiclone may lead to physical and psychological dependence. The risk of non-medical use and dependence increases with the dose and duration of usage and concomitant use of other psychoactive substances. The risk is also greater in patients with a history of alcohol use disorder or other substance use disorder or history of psychiatric disorders. Tolerance may develop after repeated use of benzodiazepines and benzodiazepine-like drugs for a few weeks.
  A study funded and carried out by Sepracor, the manufacturer of eszopiclone, found no signs of tolerance or dependence in a group of patients followed for up to six months.