Later sleep schedule and depressive symptoms are associated with usage of multiple kinds of hypnotics.

OBJECTIVE: Usage of high doses of hypnotics possibly causes various adverse events. However, the risk factors of using multiple kinds of hypnotics have been inconclusive. To clarify this, we conducted a web-based cross-sectional questionnaire survey on the Japanese adult population.

METHODS: A cross-sectional Internet-linked survey was conducted on 10,016 individuals and 1030 participants (10.3%) having subjective insomnia proceeded to subsequent analyses. The analyzed subjects were categorized into non-users of hypnotics (n = 833; 80.9%), users of a single kind of hypnotic (n = 96; 9.3%), and users of multiple kinds of hypnotics (n = 101; 9.8%). The descriptive variables including demographic data, scores of Center for Epidemiological Studies Depression Scale (CES-D), Short Form-8 Health-Related Quality of Life [QOL (SF-8)], Pittsburgh Sleep Quality Index (PSQI), and other parameters were compared among the groups.

RESULTS: The users of multiple kinds of hypnotics had the highest mean score of CES-D, the lowest mental component summary of QOL (SF-8), and the latest sleep schedule among the three groups (p < 0.001). Logistic regression analyses revealed that sex (female: OR = 2.38; p < 0.001) and age (≥43 years old: OR = 2.61; p < 0.001) were independently associated with use of a single kind of hypnotic, while later sleep schedule (midpoint of sleep ≥5:30 a.m.: OR = 2.26; p < 0.001) and higher CES-D score (≥16 points: OR = 2.41; p < 0.001) were independently associated with use of multiple kinds of hypnotics.

CONCLUSIONS: Characteristics of users of multiple kinds of hypnotics were different from those of users of a single kind of hypnotic.