Correlates of dependence and beliefs about the use of hypnotics among zolpidem and zopiclone users

Background: Zolpidem and zopiclone are the two most commonly prescribed Z-drugs approved to treat insomnia. Objectives: To examine the demographic and clinical correlates of dependence and beliefs about hypnotic use among long-term zolpidem and zopiclone users in psychiatric treatment for insomnia. Methods: A total of 392 psychiatric outpatients who received zolpidem or zopiclone treatment for at least 3 months for insomnia were studied. Participants' severity of hypnotic dependence and beliefs about the use of hypnotics to treat sleep problems were assessed. The correlation of dependence and beliefs about zolpidem and zopiclone treatment with demographic characteristics, hypnotic-using behaviors, co-use of addictive substances, and depressive symptoms were analyzed using multiple regression analysis models. Results: Zolpidem users reported more severe dependence and a lower level of necessity regarding the use of hypnotics than zopiclone users did. High equivalent doses of hypnotics and long duration of use were significantly associated with severe dependence and a low level of necessity. Severe depressive symptoms were signiciantly associated with severe dependence, a low level of necessity, and a low level of concern. Educational level was also associated with the levels of concern and necessity. Conclusions/Importance: There were differences in the level of dependence and belief about hypnotic use between zolpidem and zopiclone users. The correlates of dependence and belief identified in this study can serve as the basis for prevention and intervention programs.